Dissertations / Theses on the topic 'Alveolar bone regeneration'

Pathological processes in the alveolar and facial bones can lead to bone loss that may not heal with complete regeneration. Biomaterials can be used to facilitate the healing process and/or as a bone substitute, but the mechanisms are not fully understood. Persistent leakage of bacteria/bacterial toxins, after root canal treatment, may lead to a residual bone defect. The healing is dependent on a placed dental biomaterial providing a tight seal. The composition of the filling material may also influence the healing process. The general aim of this study is to investigate surface properties and biological interactions of biomaterials used in dento-alveolar surgery. A dental biomaterial, a bonded compomer (DAP) containing a corroding glass filler, was used as a root end filling material, promoting a new operation technique. The healing (assessed according to Molven´s x-ray criteria) demonstrates a significant improvement in healing results for the compomer group, compared to a commonly used technique. The surface properties and biological interactions of DAP were analyzed. ICP-OES of DAP cell culture medium extract demonstrated a significant release of Sr, Si and F from the dental biomaterial. Human periodontal ligament (PDL) cells grew on and around DAP specimens without any sign of toxic reactions. DAP extract stimulated proliferation of PDL cells, but caused an inhibition of osteoblastic gene expression in mouse bone marrow cells. The surface properties of the glass containing compomer may contribute to improved healing of the periapical lesions. A bovine inorganic bone graft substitute (BO) is commonly used as a treatment option in dento-alveolar surgery with new bone formation in immediate close contact with BO material. ICP-OES dissolution analysis of cell culture media, after incubation with BO particles, demonstrated a dosedependent release of Si and a decrease of Ca and P. An uptake of Ca from the medium to the BO particle was demonstrated with calcium-45 labeling. The Si dissolution varied between different batches, possibly reflecting a variation in food intake in the animals. Stimulated osteogenic response was seen in close contact to the BO particles in cell cultures. Furthermore, it was clearly demonstrated that the study design is a critical factor for correctly understanding biomaterials’ biological interactions. The surface properties of three bone graft substitutes reported to have good results in dento-alveolar surgery were investigated, in order to establish whether or not dissolution-precipitation reactions could contribute to the bone healing. Dissolution-precipitation extracts of BO, bioactive glass 45S5 (BG) and a marine algae hydroxyl apatite (AP) in cell culture media were analyzed. Dissolution of Si at significant levels was detected for BO and 45S5 over time. Significant uptake levels of Ca and P from the culture were seen for both 45S5, BO and AP but at different times. Surface analysis of the biomaterials with SEM/EDAX, before and after immersion in cell culture media, revealed a smoothing of the surface morphology for 45S5 over time. No obvious alterations for BO and AP were detected. Ca/P ratio decreased significantly for 45S5, but no major changes were detected by XPS for BO or AP. XPS further demonstrated a surface charge for BO, changing from negatively to positively charged when exposed to serum. 45S5 and AP had positive surface charges, both in the absence and the presence of serum. These demonstrated surface changes in biomaterials could contribute to adherence of cells and subsequently affect bone healing. Conclusion: Biomaterials used in dento-alveolar surgery interact with biological surroundings through surface and dissolution-precipitation reactions which may have implications for bone healing.

Peri implant and periapical bone defects are widespread in the world population. Considering the high number of implant placement and root canal treatment performed every year, resolution of these bone defects will be of predominant interest in the next future. The present project has several aims: The first part of the project aimed to investigate how and what factors affect peri implant bone remodeling process. Microchemical analysis of the peri implant bone interface of retrieved human dental implants was performed. In addition, prospective clinical studies were conducted to evaluate the factors mostly related to peri implant bone loss. The second part of the project aimed to evaluate chemical physical and micromorphological properties of hydraulic calcium silicates based materials (CaSi), which gained a particular attention in the endodontic field. Use of these materials claimed to resolve several complex endodontic complications, however few information is present in literature. These materials were compared with some “gold standard” bioinert materials. Given the attractive biointeractive properties of CaSi based materials, the last part of the study will focus on the design and characterization of new mineral based scaffolds, aimed to be applied in future bone regeneration procedures. Scaffolds, composed of a polymeric matrix were doped with CaSi and calcium phosphates, in order to increase the materials biointeractive properties. A complete characterization of their chemical-physical-mechanical-thermal properties was performed, as well as the evaluation of apatite forming ability (bioactivity) and biocompatibility of these mineral based scaffolds. The combination of Human Periapical-cysts Mesenchymal Stem Cells (hPC-MSC) as a potential strategy to achieve periapical bone regeneration was evaluated. Finally, the angiogenesis potential of these scaffolds was investigated through the growth and proliferation of porcine vascular wall mesenchymal stem cells (pvw-MSC) was performed.

This PhD thesis is a compendium of three publications, which sets out to broaden our knowledge and understanding of the topical application of bisphosphonates alone or mixed with a bone graft in alveolar bone defects, to evaluate the potential capacity of them to preserve/enhance alveolar new bone formation. In recent years, research has focused on improving bone substitutes to achieve faster and better regeneration by morphologic and biochemical modification. Bisphosphonates are a group of drugs that reduce bone resorption by inhibiting the formation, recruitment activity of mature osteoclasts; and promoting their apoptosis. In addition, some bisphosphonates enhance osteoblast differentiation and activity. Thence, it has been demonstrated that topical application of a bisphosphonates can minimize the bone resorption following muco-periostial flap surgery or in peri- implantitis; improve the osteoconductive and regenerative capacity of a biomaterial; prevent the surface resorption of onlay bone grafts; or reduce post-extraction dimensional changes. Mandibular second premolars (P2) and first molars (M1) were extracted from six Fox-Hound dogs. P2 were categorized as small defects (SD) and M1 as large defects (LD). Four random groups were created: SC (small control defects with MP3®), ST (small test defects MP3® + pamidronate), LC (large control defects with MP3®), and LT (large test defects MP3® + pamidronate). At four and eight weeks of healing the percentages of new bone formation (NB), residual grafts (RG) and connective tissue (CT) were analysed by histology and histomorphometric analysis. To complement the information already obtained from histological analysis, the samples were evaluated through scanning electron microscopy (SEM), and Energy dispersive X-ray spectroscopy (EDX), to identify the chemical elements present into the biomaterial and surrounding tissues, for understanding the biomaterial’s degradation process. The study was complemented with a systemic literature review of the articles published between January 2000 and December 2016, that evaluated in vivo the effects of the topical application of bisphosphonates on bone regeneration/preservation in alveolar defects. A total of 154 abstracts were identified, of which 18 potentially relevant articles were selected; a final total of nine papers were included for analysis. Histomorphometric and histologic analysis of the present pilot study demonstrated that after 4 and 8 weeks of healing, higher new bone formation for test groups (ST and LT) treated topically with pamidronate, compared with SC and LC respectively; residual graft was significantly higher in both control groups (SC and LC) compared to test (ST and LT) groups; and connective tissue percentage was higher in large defects (LC and LT) compared to small defects (SC and ST). SEM analysis revealed more mineralized bone in test groups (ST and LT) compared with control groups, demonstrated by higher percentages of Ca obtained from EDX spectroscopy. Within the limitations of this experimental study, the findings suggest that porcine xenografts (MP3®) modified with pamidronate favours the new bone formation and increased the porcine xenograft substitution/replacement after 4 and 8 weeks of healing. These results are in accordance with the conclusions obtained from the systematic review. Despite the comparison of the findings of the selected studies was made difficult by the heterogeneity of the articles, the topical application of bisphosphonate solution would appear to favour new bone formation in alveolar defects, and boosts the regenerative capacities of biomaterials resulting in increased bone density.

O objetivo deste trabalho foi comparar os parâmetros clínicos periodontais após tratamento de defeitos infra-ósseos com retalho de espessura total (RET) associado ou não à proteína da matriz do esmalte (PME). Foram selecionados 10 pacientes com saúde geral boa, apresentando periodontite crônica e com um par ou mais de defeitos infra-ósseos (PCS >= 6 mm), totalizando 38 defeitos. Todos os pacientes receberam instruções de higiene bucal, raspagem e alisamento radicular, prévio a cirurgia. Foram divididos em dois grupos: grupo PME recebeu retalho de espessura total associado à proteína da matriz do esmalte; e o grupo RET recebeu apenas retalho de espessura total. Todos os pacientes passaram por sessões de controle e manutenção bucal a cada 3 meses, até o final do experimento. Após 24 meses observamos redução na média da PCS de 4,21 mm (PME) e 3,28 mm (RET),do início ao final do experimento, resultado significativo para ambos os grupos (p < 0,001), entretanto, o PME mostrou redução da PCS estatisticamente superior ao RET, aos 24 meses (p = 0,030). Para o NCIR o ganho médio foi de 5,69 mm (PME) e de 5,24 mm (RET), sendo esses ganhos significativos para ambos os grupos (p < 0,001) comparados o início ao final do experimento, no entanto, não houve diferença significativa quando comparadas às médias entre os dois grupos, ao final do trabalho (p = 0,59). Com relação ao IP, foi detectada uma redução significativa nos dois grupos ao longo do tratamento (p=0,022 para PME; p=0,005 para RET), 60% para o grupo PME e 80% para o grupo RET, sem contudo ser observada uma diferença estatisticamente significante entre os grupos (p=0,46). Quando observado o IG, tanto no PME como no RET, foi detectada uma redução significativa ao longo do experimento (p<0,001), entretanto, não houve diferença significativa entre os grupos em nenhum momento do experimento (p=0,34). A RG foi maior para o PME do que para o RET (p<0,001), sendo que no PME a RG aumentou 1,02 mm, apesar desse resultado, os valores médios de retração gengival não foram diferentes estatisticamente quando comparadas entre os grupos (p=0,68). Não houve alteração significativa na quantidade de gengiva queratinizada no PME (p = 0,23), enquanto no RET houve uma redução significativa na faixa de gengiva queratinizada ao longo do tempo de 0,78 mm (p=0,010), sem diferença estatística significante entre os grupos. A mobilidade dental não sofreu mudanças ao longo do tempo em ambos os grupo (p=0,90). Concluímos que o tratamento de defeitos infra-ósseos periodontais através da associação da proteína da matriz do esmalte com o retalho de espessura total reposto resulta em maior redução da profundidade clínica de sondagem quando comparado ao uso do retalho de espessura total reposto, após 24 meses.
The aim of the present clinical trial was to compare the periodontal clinical parameters after the treatment of intrabony defects with open flap debridement (OFD) with or without enamel matrix derivative (EMD). Ten subjects with good health, chronic periodontite and one or more pair of the intrabony defects (PPD >= 6 mm), totalizing 38 defects. All the patients received instructions of buccal hygiene, scaling and root planning, previous surgery. They were divided into two groups: group PME received open flap debridement associated to the enamel matrix protein; and the group OFD just received open flap debridement. All the patients passed by control sessions and buccal maintenance every 3 months, until the experiment end. After 24 months, a mean reduction of PPD was 4,21 mm (EMD) and 3,28 mm (OFD), beginning at the end of the experiment, significant result for both groups (p < 0,001), however, EMD showed PPD reduction statistically superior to OFD, at 24 months (p = 0,030). For the relative attachment level (RAL) the mean gain was 5,69 mm (EMD) and 5,24 mm (OFD), being these significant for both groups (p < 0,001) compared the beginning at the end of the experiment, however, there was not significant difference when compared to the means between both groups, at the end of the work (p = 0,59). With regard to PI, it was detected a significant reduction in the two groups along the treatment (p=0,022 to EMD; P=0,005 to OFD), 60% to the group EMD and 80% to the group OFD, without however a statistically significant difference between groups be observed (p=0,46). When observed GI, so much in the EMD as in OFP, it was detected a significant reduction along the experiment (p<0,001), however, there was not significant difference between groups in no experiment moment (p=0,34). RG was larger for EMD than for OFP (p<0,001), for EMD increased 1,02 mm, although of this result, the mean values of GR were not different statistically when compared between groups (p=0,68). There was not significant alteration in the keratinized tissue quantity in EMD (p = 0,23), while in the OFD there was a significant reduction in the keratinized tissue band along time of 0,78 mm (p=0,010), without differentiating significant statistics between groups. The dental mobility did not suffer changes along time in both group (p=0,90). In conclusion, the intra-bony periodontal defects treatment through the enamel matrix protein association with the open flap debridement results in more reduction to the probing clinical depth when compared to the open flap debridement, after 24 months.

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A ação da ocitocina (OT) como regulador direto da massa óssea foi reportada em roedores jovens e este efeito anabólico foi atribuído à ação periférica deste hormônio. O objetivo deste estudo foi investigar a ação periférica de OT no processo de reparo alveolar de ratas Wistar de 12, 18 e 24 meses. Ratas de 12 meses com ciclo estral normal e ratas de 18 e 24 meses em diestro permanente receberam duas injeções intra-peritoniais (12 horas de intervalo) de salina (NaCl 0,15M – grupos controle) ou OT (134g/Kg – grupos tratados). Sete dias após, o incisivo direito foi extraído e as análises foram realizadas com 28 dias de reparo alveolar (35 dias após administração de salina ou OT). Os resultados plasmáticos de cálcio e fósforo não diferiram entre os grupos. Os marcadores bioquímicos sistêmicos de formação óssea, fosfatase alcalina (FAL) e osteocalcina (OC), não revelaram diferença significativa de valores na comparação entre grupos controle e tratado de 12 meses, porém esta diferença foi significativa para os dois marcadores quando os animais tratados de 18 e 24 meses foram comparados com os respectivos controles. A análise histomorfométrica e a reação de imunohistoquímica contra OC confirmaram estes resultados mostrando que o tratamento com OT, promoveu maior formação óssea nos animais de 18 e 24 meses. O marcador sistêmico de reabsorção óssea, fosfatase ácida resistente ao tartarato (TRAP) não foi estatisticamente diferente entre animais dos grupos controle e tratado de 12 e 18 meses, porém nos de 24 meses este valor foi significativamente menor nos animais tratados indicando diminuição de reabsorção por ação de OT nos animais desta idade. A imunomarcação para TRAP realizada nos cortes alveolares confirmou os...
The action of oxytocin (OT) as a direct regulator of bone mass has been reported in young rodents and this anabolic effect was attributed to the peripheral action of this hormone. The aim of this study was to investigate the peripheral action of OT in the process of alveolar repair of Wistar rats with 12, 18 and 24 months. Rats of 12 months with normal estrous cycle and rats with 18 and 24 months in permanent diestrus received two intra-peritoneal injections (12 hours apart) of saline (NaCl 0.15 M - control group) or OT (134  g / kg - treated groups). Seven days later, the right incisor was extracted and the analyzes were performed with 28 days of alveolar repair (35 days after administration of saline or OT). The plasma results of calcium and phosphorus did not differ between groups. The systemic biochemical bone formation markers, alkaline phosphatase (ALP) and osteocalcin (OC), revealed no significant difference of values in animals of 12 months, but this difference was significant for both markers when treated animals of 18 and 24 months were compared to controls. The histomorphometric analysis and immunohistochemical reaction against osteocalcin confirmed these results showing that treatment with OT, promoted greater bone formation in animals with 18 and 24 months. The systemic marker of bone resorption, tartrate-resistant acid phosphatase (TRAP) was not statistically different between animals of the control and treated groups of 12 and 18 months, but in 24 months the values were significantly lower in treated animals indicating decreased resorption action of OT in animals of this age. The immunostaining for TRAP performed on alveolar cuts confirmed the results of the results of systemic markers in groups of 12 and 24 months... (Complete abstract click electronic access below)

Orientador: Rita Cássia Menegati Dornelles
Coorientador: Poli Mara Spritzer
Banca: João Cesar Bedran de Castro
Banca: Roberta Okamoto
Banca: Keico Okino Nonaka
Banca: Marcelo Alves da Silva Mori
Resumo: A ação da ocitocina (OT) como regulador direto da massa óssea foi reportada em roedores jovens e este efeito anabólico foi atribuído à ação periférica deste hormônio. O objetivo deste estudo foi investigar a ação periférica de OT no processo de reparo alveolar de ratas Wistar de 12, 18 e 24 meses. Ratas de 12 meses com ciclo estral normal e ratas de 18 e 24 meses em diestro permanente receberam duas injeções intra-peritoniais (12 horas de intervalo) de salina (NaCl 0,15M - grupos controle) ou OT (134g/Kg - grupos tratados). Sete dias após, o incisivo direito foi extraído e as análises foram realizadas com 28 dias de reparo alveolar (35 dias após administração de salina ou OT). Os resultados plasmáticos de cálcio e fósforo não diferiram entre os grupos. Os marcadores bioquímicos sistêmicos de formação óssea, fosfatase alcalina (FAL) e osteocalcina (OC), não revelaram diferença significativa de valores na comparação entre grupos controle e tratado de 12 meses, porém esta diferença foi significativa para os dois marcadores quando os animais tratados de 18 e 24 meses foram comparados com os respectivos controles. A análise histomorfométrica e a reação de imunohistoquímica contra OC confirmaram estes resultados mostrando que o tratamento com OT, promoveu maior formação óssea nos animais de 18 e 24 meses. O marcador sistêmico de reabsorção óssea, fosfatase ácida resistente ao tartarato (TRAP) não foi estatisticamente diferente entre animais dos grupos controle e tratado de 12 e 18 meses, porém nos de 24 meses este valor foi significativamente menor nos animais tratados indicando diminuição de reabsorção por ação de OT nos animais desta idade. A imunomarcação para TRAP realizada nos cortes alveolares confirmou os... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The action of oxytocin (OT) as a direct regulator of bone mass has been reported in young rodents and this anabolic effect was attributed to the peripheral action of this hormone. The aim of this study was to investigate the peripheral action of OT in the process of alveolar repair of Wistar rats with 12, 18 and 24 months. Rats of 12 months with normal estrous cycle and rats with 18 and 24 months in permanent diestrus received two intra-peritoneal injections (12 hours apart) of saline (NaCl 0.15 M - control group) or OT (134  g / kg - treated groups). Seven days later, the right incisor was extracted and the analyzes were performed with 28 days of alveolar repair (35 days after administration of saline or OT). The plasma results of calcium and phosphorus did not differ between groups. The systemic biochemical bone formation markers, alkaline phosphatase (ALP) and osteocalcin (OC), revealed no significant difference of values in animals of 12 months, but this difference was significant for both markers when treated animals of 18 and 24 months were compared to controls. The histomorphometric analysis and immunohistochemical reaction against osteocalcin confirmed these results showing that treatment with OT, promoted greater bone formation in animals with 18 and 24 months. The systemic marker of bone resorption, tartrate-resistant acid phosphatase (TRAP) was not statistically different between animals of the control and treated groups of 12 and 18 months, but in 24 months the values were significantly lower in treated animals indicating decreased resorption action of OT in animals of this age. The immunostaining for TRAP performed on alveolar cuts confirmed the results of the results of systemic markers in groups of 12 and 24 months... (Complete abstract click electronic access below)
Doutor

PURPOSE: The aim of this study is to examine the healing of intact extraction sockets grafted with leukocyte-platelet rich fibrin (L-PRF) as compared to sockets grafted with freeze-dried bone allograft (FDBA) and a resorbable collagen barrier membrane (RCM). METHODS: This prospective randomized, examiner blinded pilot study included 17 subjects randomized to two treatment groups. Serum total cholesterol, low density lipoprotein (LDL), 25-hydroxyvitamin-D3, and platelet counts were determined preoperatively in all subjects. The experimental arm consisted of 8 posterior tooth-bounded intact extraction sites receiving L-PRF plugs. The control group consisted of 9 posterior tooth-bounded intact extraction sites receiving FDBA and RCM. An acrylic stent was fabricated to take duplicate clinical and CBCT measurements immediately post-extraction and at time of implant placement. A repeat-measures analysis of variance was utilized for statistical analysis. RESULTS: The study failed to detect a clinical or radiographic difference between treatment groups in horizontal or vertical ridge dimension changes. Serum cholesterol, LDL, 25-hydroxyvitamin-D3, and buccal plate thickness had a non-significant effect on outcome measurements, although there was a high prevalence of hyperlidpidemia and hypovitaminosis in the study population. CONCLUSIONS: The alveolar ridge dimension changes in intact posterior extraction sockets may be similar when either L-PRF or FDBA and RCM are utilized as socket grafting material. Although there was a high prevalence of high cholesterol and low 25-hydroxyvitamin-D3 levels in the population, this study failed to detect a significant correlation between preoperative serum levels and postoperative ridge dimension changes.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Considerando-se que o processo de reparo ósseo em suínos mostra maior proximidade nos quadros histológicos entre as variáveis estudadas, quando comparado com outros modelos biológicos, teve-se como propósito no presente estudo comparar histologicamente o processo de reparo ósseo em suínos após osteotomias realizadas em osso alveolar e extra-alveolar, empregando-se instrumentos giratórios com refrigeração liquida, de baixa e ultravelocidade. Foram utilizados dezoito suínos da raça Large White com peso corporal entre 20 e 25 Kg, divididos em 3 grupos de seis animais cada, sendo cada grupo constituído por três animais para avaliação do reparo de osteotomias realizadas em osso alveolar e outros três em osso extra-alveolar, nos tempos pós-operatórios de 7, 14 e 28 dias. Foi observado que para o osso alveolar nos tempos pós-operatórios de 14 e 28 dias, os melhores resultados de reparo ósseo ocorreram nas osteotomias realizadas com brocas de baixa velocidade, ao passo que no tempo pós-operatório de sete dias, os resultados do reparo ósseo de osteotomias realizadas com brocas de ultravelocidade foram discretamente melhores, tanto nas áreas alveolares como extra-alveolares. Pela metodologia empregada, não se identificaram diferenças significativas no processo de reparo ósseo alveolar e extra-alveolar nos tempos pós-operatórios estudados
The aim of this study was to compare histologically the process of bony repair in swine after osteotomy accomplished in alveolar and extra-alveolar bone using rotative instruments of drop and ultra speed and liquid refrigeration. Eighteen swine of the race Large White between 20 and 25 Kg were divided in 3 groups of six animals, being each group constituted by three animals for evaluation of the osteotomy repair accomplished in alveolar and other bone three in extra-alveolar bone. The postoperative evaluation happened in the times of 7, 14 and 28 days. It was observed that for the alveolar bone in the final postoperative times, of fourteen and twenty-eight days, the best results of bony repair were observed in osteotomy accomplished with drills of low rotation, while in the postoperative time of seven days, the results of the bony repair of osteotomy accomplished with drills of high rotation they were better. The authors consider that the process of bony repair in swine display larger proximity in the histoloogical pictures among the studied variables, when compared with other biological models. As most of the works told in the literature refers the use of dogs, the authors consider that the present work guarantees your importance in the sense of looking for a closer model of the man, so much in the alveolar as extra-alveolar areas. For the used methodology, they didn't identify significant differences in the process of alveolar and extraalveolar bony repair in the studied postoperative times

Orientador: Alvimar Lima de Castro
Banca: Iracy Costa
Banca: Cleverson Luciano Trento
Banca: Gilberto Aparecido Coclete
Banca: Elerson Gaetti Jardim Junior
Resumo: Considerando-se que o processo de reparo ósseo em suínos mostra maior proximidade nos quadros histológicos entre as variáveis estudadas, quando comparado com outros modelos biológicos, teve-se como propósito no presente estudo comparar histologicamente o processo de reparo ósseo em suínos após osteotomias realizadas em osso alveolar e extra-alveolar, empregando-se instrumentos giratórios com refrigeração liquida, de baixa e ultravelocidade. Foram utilizados dezoito suínos da raça Large White com peso corporal entre 20 e 25 Kg, divididos em 3 grupos de seis animais cada, sendo cada grupo constituído por três animais para avaliação do reparo de osteotomias realizadas em osso alveolar e outros três em osso extra-alveolar, nos tempos pós-operatórios de 7, 14 e 28 dias. Foi observado que para o osso alveolar nos tempos pós-operatórios de 14 e 28 dias, os melhores resultados de reparo ósseo ocorreram nas osteotomias realizadas com brocas de baixa velocidade, ao passo que no tempo pós-operatório de sete dias, os resultados do reparo ósseo de osteotomias realizadas com brocas de ultravelocidade foram discretamente melhores, tanto nas áreas alveolares como extra-alveolares. Pela metodologia empregada, não se identificaram diferenças significativas no processo de reparo ósseo alveolar e extra-alveolar nos tempos pós-operatórios estudados
Abstract: The aim of this study was to compare histologically the process of bony repair in swine after osteotomy accomplished in alveolar and extra-alveolar bone using rotative instruments of drop and ultra speed and liquid refrigeration. Eighteen swine of the race Large White between 20 and 25 Kg were divided in 3 groups of six animals, being each group constituted by three animals for evaluation of the osteotomy repair accomplished in alveolar and other bone three in extra-alveolar bone. The postoperative evaluation happened in the times of 7, 14 and 28 days. It was observed that for the alveolar bone in the final postoperative times, of fourteen and twenty-eight days, the best results of bony repair were observed in osteotomy accomplished with drills of low rotation, while in the postoperative time of seven days, the results of the bony repair of osteotomy accomplished with drills of high rotation they were better. The authors consider that the process of bony repair in swine display larger proximity in the histoloogical pictures among the studied variables, when compared with other biological models. As most of the works told in the literature refers the use of dogs, the authors consider that the present work guarantees your importance in the sense of looking for a closer model of the man, so much in the alveolar as extra-alveolar areas. For the used methodology, they didn't identify significant differences in the process of alveolar and extraalveolar bony repair in the studied postoperative times
Doutor

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A remodelação tecidual ocorre em todos os alvéolos dentais após a extração do elemento dentário, comprometendo a reabilitação funcional e estética do paciente. O objetivo do presente estudo foi avaliar as alterações dimensionais alveolares ocorridas com a técnica da preservação alveolar com pôntico ovóide provisório, comparando-a com outras duas técnicas já estabelecidas. Trinta pacientes foram selecionados e divididos em três grupos de acordo com a técnica de preservação alveolar utilizada: Grupo 1: fechamento com deslize de retalho palatino; Grupo 2: associação de substituto ósseo sintético de fosfato de cálcio bifásico e fechamento com deslize de retalho palatino; e Grupo 3: vedamento das margens do alvéolo com pôntico ovóide provisório. Modelos de gesso e exames de tomografia computadorizada de feixe cônico (TCFC) realizados antes das cirurgias e no pós-operatório imediato respectivamente, e repetidos após quatro meses, foram utilizados para comparar a remodelação alveolar. Os resultados encontrados demonstraram que houve remodelação óssea horizontal em todos os grupos com resultados semelhantes entre as três técnicas. Entretanto, todas as técnicas avaliadas foram capazes de manter as dimensões verticais do rebordo alveolar durante o período de quatro meses sem diferença estatisticamente significativa entre elas. Conclui-se que a técnica proposta do pôntico ovóide provisório é eficaz na preservação alveolar, visto que apresentou resultados semelhantes a técnicas já estabelecidas, além de gerar menor morbidade, menor custo e ser facilmente reproduzível.
Tissue remodeling occurs in sockets after tooth extraction, compromising the functional and aesthetic rehabilitation of the patient. The aim of this study was to evaluate the efficacy of the sealing technique with provisional pontic ovoid for ridge preservation compared with two other standard techniques. Thirty patients were selected and divided into three groups according to the used ridge preservation technique: Group 1: closure with palatal pedicle flap; Group 2: association of synthetic bone substitute and closure with palatal pedicle flap; Group 3: sealing the margins of the socket with a provisional ovoid pontic. Plaster casts and cone-beam computed tomography (CBCT) exams performed before the surgeries and at immediate postoperatively, respectively, and repeated after four months, were used to compare socket remodeling. The results demonstrated horizontal bone remodeling in all groups with similar results noted among all groups. However, the three techniques were able to maintain the vertical dimensions of the ridge over the four-month period without significant statistical diferences among them. It is concluded that the proposed technique involving provisional ovoid pontic is effective in ridge preservation, once it presented similar results to previously established techniques, besides generating lower morbidity, lower cost and being easily reproducible.

A cicatrização de um alvéolo após a extração dental é uma resposta reparadora. Após a exodontia, a cicatrização espontânea irá levar à perda do volume e do formato do rebordo original. A preservação alveolar envolve qualquer procedimento que limite os efeitos da reabsorção pós-extração. O objetivo deste estudo foi avaliar o uso de um substituto ósseo xenogênico na preservação alveolar pós-extração dental comparado com a cicatrização espontânea em dentes anteriores da maxila com defeitos ósseos da parede vestibular maiores do que 50%. Foram tratados 13 pacientes com necessidade de exodontia de dente anterior da maxila com perda >50% da parede vestibular. Todas as exodontias foram realizadas sem retalho. Os pacientes foram alocados aleatoriamente em grupo teste: preservação alveolar com substituto ósseo (7 participantes) e grupo controle: cicatrização espontânea (6 participantes). O desfecho primário foi a alteração dimensional do rebordo alveolar calculada entre as imagens tomográficas de início (pós-exodontia) e depois de 4 meses da intervenção, na espessura 1mm abaixo da porção coronal da crista (HW-1). Os desfechos secundários foram as medidas vestibular e palatina, e os segmentos transversais HW-3 e HW-5. A medida HW-1 reduziu 51,21 % no grupo teste e 82,80% no grupo controle, com uma diferença intergrupos estatisticamente significante de 31,59%. Para as medidas transversais, houve redução estatisticamente significante tanto para HW-3 quanto para HW-5 entre os dois grupos. Em alvéolos com perda da parede vestibular maior que 50%, a utilização do substituto ósseo promoveu uma menor perda horizontal na ordem de 30%.
The healing process of post-extraction sockets is bone resorption. After tooth extraction, spontaneous healing will lead to loss of volume and shape of the original ridge. Alveolar ridge preservation involves any procedure that limits the effects of post-extraction resorption. The objective of this study was to evaluate the use of the xenogenic bone substitute in the post-extraction alveolar preservation compared to spontaneous healing in anterior maxilla teeth with vestibular wall defects greater than 50%. Thirteen patients with anterior maxillary tooth extraction with a > 50% buccal wall loss were treated. All the surgeries were made flapless. Patients were randomly assigned to a test group: alveolar preservation with bone substitute (7 participants); and control group: spontaneous healing (6 participants). The primary outcome was the dimensional alteration of the alveolar ridge calculated between the tomographic images at the beginning (post-extraction) and after 4 months of the intervention, at the thickness 1mm below the coronal portion of the crest (HW-1). Secondary outcomes were measures buccal and palatine, and HW-3 and HW-5 cross-sections. The HW-1 measure reduced 51.21% in the test group and 82.80% in the control group, with a statistically significant intergroup difference of 31.59%. For the other horizontal measurements, there was a statistically significant reduction for both HW-3 and HW-5 between the two groups. In sockets with buccal wall loss greater than 50%, the use of the bone substitute provided a 30% lower horizontal loss.

Resumo: Objetivo:Avaliar a atuação do E2 durante a regeneração alveolar, utilizando a expressão das proteínas OPG, RANK e RANKL como indicadores celulares de predisposição à reabsorção ou formação de tecido ósseo. Material e métodos: Após 8 dias da cirurgia SHAM ou ovariectomia (OVX), as ratas (200g) OVX receberam implantes subcutâneos contendo óleo de milho (grupo OVX/óleo) ou E2 (400μg) (grupo OVX/E2). As exodontias dos incisivos superiores direitos foram realizadas no decorrer do tratamento e agendadas para que ao término de 60 dias fosse possível obter as peças referentes a 14, 28 e 42 dias de regeneração óssea alveolar. As peças foram submetidas a processamento imunoistoquímico. Resultados: Nos animais com ciclo estral regular (grupo SHAM), foi observada expressão baixa aos 14, média/alta aos 28 e a não expressão de OPG e RANKL aos 42 dias. A expressão de RANK iniciou alta e foi diminuindo até o último período analisado. No grupo OVX/Óleo a expressão de RANKL foi crescente até o término da análise aos 42 dias, enquanto que a expressão de RANK diminuiu ao longo do período estudado. Foi observada expressão de OPG no início e ao final do período analisado. Os animais OVX/E2 apresentaram marcação semelhante para OPG, RANK e RANKL aos 14 dias. A expressão de RANKL foi observada até o final do experimento, entretanto não foi detectada expressão de OPG e RANK aos 28 e 42 dias. Conclusão: Estes resultados evidenciam a participação do E2 modulando o ciclo de remodelação óssea alveolar.
Abstract: Objective: To evaluate the role of E2 during alveolar bone regeneration, using OPG, RANK and RANKL protein expression as cellular indicators of predisposition to resorption or bone tissue formation. Methods: Eight days after either SHAM surgery or ovariectomy (OVX), the OVX rats (200g) received subcutaneous implants with corn oil (OVX/oil group) or E2 (400μg) (OVX/E2 group). Extraction of the maxillary right incisors were performed during the course of the treatment and was scheduled in such a way that at the end of a 60-day period it would possible to retrieve anatomic pieces referring to 14, 28 and 42 days of alveolar bone healing. The pieces were submitted to immunohistochemical processing. Results: In the animals with regular estrous cycle (SHAM group), it was observed low expression at 14 days, medium/high expression at 28 days and no OPG and RANKL expression at 42 days. RANK expression started high and decreased continuously up to the last analyzed period. In the OVX/oil group, RANKL expression increased up to the completion of the analysis at 42 days, whereas RANK expression decreased within the studied period. OPG expression was observed in the beginning and the end of the analyzed period. The animals OVX/E2 showed similar labeling for OPG, RANK and RANKL at 14 days. RANKL expression was observed up to the end of the experiment. However, no OPG and RANK expression was detected at 28 and 42 days. Conclusion: These results demonstrate the role of E2 modulating the alveolar bone remodeling cycle.
Orientador: Idelmo Rangel Garcia Júnior
Coorientador: Rita Cássia Menegati Dornelles
Banca: Ana Maria Pires Soubhia
Banca: Teresa Lucia Lamano Carvalho
Mestre

O metabolismo ósseo é influenciado por fatores endócrinos, genéticos, de crescimento, sistema RANK/RANKL/OPG, além de uma variedade de moléculas regulatórias, como as citocinas. Citocinas têm sido implicadas na patogênese de doenças ósseas, no entanto, ainda pouco se sabe sobre os mecanismos envolvidos na interação entre o sistema ósseo e imunológico no processo de reparo ósseo. O objetivo deste estudo foi caracterizar o papel de TNF-α e IL-10 no reparo ósseo alveolar em condições homeostáticas (controle [C]) e infecciosas (alveolite experimental [A]) pós exodontia em camundongos C57Bl/6 (WT), TNFp55KO e IL-10KO. Após a cirurgia nos grupos infectados foi induzida a alveolite por meio de isquemia do alvéolo e uma suspensão de secreção purulenta. As maxilas foram coletadas em 0h, 7, 14 e 21 dias após a extração do incisivo superior para análises histológica, histomorfométrica e molecular (RealTimePCR). Na análise histomorfométrica foram quantificados os parâmetros coágulo, células inflamatórias, fibras, fibroblastos, vasos sanguíneos, matriz óssea, osteoblastos, osteoclastos, e outros espaço do líquido intersticial e medula óssea. Na análise molecular (RealTimePCR) foram quantificados a expressão de fatores de crescimento, marcadores ósseos e de matriz extracelular, citocinas e quimiocinas envolvidos no processo. Os dados obtidos foram submetidos ao teste OneWay ANOVA seguido do teste de comparação múltipla de Tukey. Os resultados demonstraram que nos camundongos WT-C houve a formação inicial de coágulo (0 hora) com início da expressão de BMP2, BMP4, BMP7, TGFb1 and VEGFa que tiveram aumento gradativo com pico em 7 dias. A expressão de TNF-α e IL10 também tiveram seus picos aos 7 dias em paralelo com contagem de leucócitos, associado com a expressão de CCL2, CCL5 e CXCL1. Nos períodos seguintes houve uma diminuição inflamatória e o aumento de marcadores osteoblásticos/osteogênicos. A indução da alveolite experimental em WT-A resultou no aumento marcante na expressão de TNF-α, acompanhada por uma maior expressão de CXCL1 e CCL5, contagem aumentada de leucócitos e diminuição na expressão de IL-10 que só atingiu seu pico aos 14 dias, além de proeminente infiltrado leucocitário e tecido de granulação, bem como evidências histológicas de atraso no reparo ósseo. O impacto negativo da alveolite foi atenuado nos camundongos TNFp55KO, caracterizado por um reparo adequado, diminuição no número de leucócitos e osteoclastos em relação aos WTA. Por outro lado, um atraso no reparo foi observado nos animais IL10KO, evidenciado por uma menor densidade de osteoblastos e de matriz óssea do que o respectivo controle. Em conclusão, os resultados mostraram que ambas citocinas interferem no reparo ósseo alveolar por meio de mecanismos que envolvem o controle da migração de células inflamatórias e modulação de quimiocinas e a expressão de marcadores osteogênicos, uma vez que a ausência de IL-10 está associada a uma maior atividade inflamatória e reabsorção óssea concomitante com menor formação ósseo, já a deficiência de TNF-α afeta o recrutamento de leucócitos e a cinética de reparo óssea alveolar em condições homeostáticas e infecciosas.
Bone metabolism is influenced by endocrine, genetic and growth factors, RANK/RANKL/OPG system, besides a variety of regulatory molecules, such as cytokines. Cytokines have been implicated in pathogenesis of bone diseases, however, little is known about the mechanisms involved in the interaction between skeletal and immune system in the bone repair process. The objective of this study was characterized the role of TNF-α and IL-10 in alveolar bone repair under homeostatic (control [C]) and infectious (experimental alveolitis [A]) conditions in C57Bl/6 (WT), TNFp55KO and IL-10KO mice. After surgery, in infectious groups was induced by ischemia alveolitis the well and a suspension of pus. The maxillas were collected at 0h, 7, 14 and 21 days after extraction of the maxillary incisor for histologic, histomorphometric and molecular (RealTimePCR). In histomorphometric analysis parameters were measured clot, inflammatory cells, fibers, fibroblasts, blood vessels, bone matrix, osteoblast, osteoclast, and other space - the interstitial fluid and bone mar row. Molecular analysis (RealTimePCR) were quantified the expression of growth factors, bone markers and extracellular matrix, cytokines and chemokines involved in the process. The data were submitted to the OneWay ANOVA test followed by Tukey\'s multiple comparison test. The results showed that in WT-C initial clot formation (0 hours) with early expression of BMP2, BMP4, BMP7, and TGFb1 VEGFa who had gradual increase peaking in 7 days. The expression of TNF-α and IL10 also peaked at 7 days in parallel with leukocyte count, associated with CCL2, CCL5 and CXCL1. In late periods there were decrease of inflammation and markers osteoblastic / osteogenic increased. Induction of experimental alveolitis in WT resulted in a marked increase in expression of TNF-α accompanied by increased expression of CXCL1 and CCL5, increased leukocyte count and decreased of IL10 expression that peaked at 14d, besides prominent leukocyte infiltration and granulation tissue, as well as histological evidence of delayed bone repair. Negative impact of alveolitis was attenuated in TNFp55KO mice, characterized by appropriate repair rate, decreased of the number of leukocytes and osteoclasts that WT-A. On the other hand, a lessened repair was observed in IL10KO animals, evidenced by lower density of the density of osteoblasts and bone matrix than respective control. In conclusion, the results show that both cytokines interferes in alveolar bone repair through mechanisms that involve the control of inflammatory cell migration and modulation of chemokines and osteogenic markers expression, since that the absence of IL-10 is associated with higher inflammatory activity and bone resorption concomitant with lower bone formation, while the deficiency of TNF-αa affect the recruitment of leukocytes and the kinetics of alveolar bone healing both in homeostatic and infectious conditions.

1.1. ASTRATTO OBIETTIVI: Lo scopo di questa revisione era di esplorare lo sviluppo degli espansori di tessuti molli, i loro diversi tipi e le loro potenziali applicazioni prima dell'innesto osseo e del posizionamento dell'impianto. MATERIALI E METODI: è stata eseguita una revisione della letteratura pertinente utilizzando PubMed per comprendere la dinamica degli espansori dei tessuti molli e determinare la posizione corrente delle loro applicazioni di pre-incremento. RISULTATI: Ci sono informazioni preliminari sui benefici dell'espansione dei tessuti molli pre-allargamento (STE). I risultati non possono essere generalizzati a causa delle dimensioni campionarie relativamente ridotte degli scarsi studi clinici disponibili in letteratura. CONCLUSIONI: Sono necessari ulteriori studi clinici con campioni di dimensioni maggiori e follow-up a lungo termine prima che gli espansori dei tessuti molli possano essere applicati con sicurezza nella pratica clinica quotidiana.2.1. ASTRATTO OBIETTIVI: Indagare sugli esiti clinici, le complicanze e l'aumento di volume dell'espansione dei tessuti molli pre-aumento (STE). MATERIALI E METODI: Espansori tissutali sono stati impiantati in sette pazienti che richiedono l'aumento osseo verticale e / o orizzontale. La rigenerazione ossea guidata (GBR) è stata effettuata dopo 20, 40 o 60 giorni di STE. I guadagni ossei verticali e orizzontali sono stati analizzati con la tomografia computerizzata a fascio conico (CBCT). Per l'analisi volumetrica sono state utilizzate la scansione ottica e la sovrapposizione di modelli di fusione fabbricati da impronte di alginato pre- e post-augmentazione. RISULTATI: sette siti su sette pazienti sono stati trattati con STE. La perforazione si è verificata in due siti; guasto precoce dovuto alla tenuta della sacca preparata, e ritardo in ritardo a causa di piccole fessure del guscio di silicio che coprono l'espansore a seguito della manipolazione del corpo dell'espansore con una pinzetta dentale. Dopo la dilatazione, la chiusura della ferita primaria è stata facilmente ottenuta con l'aumento senza successive esposizioni del trapianto. Sei mesi dopo l'aumento, l'analisi CBCT ha rivelato un guadagno osseo verticale elevato (media = 7,3 ± 1,2 mm). La media del guadagno osseo orizzontale era di 5,5 ± 2,9 mm. L'analisi volumetrica di tre casi di espansione ha rivelato un aumento medio del volume di 483,8 ± 251,7 mm3. L'aumento del volume dei tessuti molli corrispondeva solo all'espansore del cilindro da 0,24 ml (aumento del volume = 259,4 mm3), mentre questo aumento era quasi la metà del volume dell'espansore finale per gli espansori del cilindro da 0,7 e 1,3 ml (rispettivamente 436,1 mm3 e 755,9 mm3). Tutti gli impianti dentali sono stati osteointegrati nei pazienti sottoposti a successiva terapia implantare. CONCLUSIONI: Elevato guadagno osseo verticale e complicanze post-chirurgiche minime sono state associate a procedure di aumento osseo precedute dall'espansione dei tessuti molli (STE).4.1. ASTRATTO OBIETTIVI: Analizzare i pattern di riassorbimento osseo nelle mandibole posteriori e i corrispondenti innesti ossei digitalmente progettati per capire se si presentano in cluster distinti. MATERIALI E METODI: In questa analisi retrospettiva, sono state analizzate 120 scansioni CBCT per valutare la frequenza della classificazione di Cawood e Howell, nelle mandibole posteriori destra e sinistra. I risultati sono stati confrontati tra sesso ed età. La classe atrofica più frequente che ha bisogno di aumento osseo è stata virtualmente rigenerata nei segmenti mandibolari utilizzando un software specifico. Altezza, larghezza e lunghezza degli innesti ottenuti sono stati analizzati per concludere se questi innesti si presentano in cluster distinti. Risultati. La classe V era la classe atrofica più frequente rispetto alla classe IV e VI nelle mandibole posteriori sinistra e destra (16%, 20,8% rispettivamente). Gli stadi atrofici gravi erano più frequenti nelle femmine (p = 0,029 per il lato sinistro, p = 0,007 per il lato destro) e nei gruppi di età più avanzata (p = 0,008 per il lato destro) Dopo la rigenerazione virtuale dei difetti della classe V, tre cluster erano evidente, che differisce solo per la lunghezza, in base al numero di denti mancanti (p = 0,0001). L'altezza e la larghezza degli innesti virtuali erano comparabili per i tre cluster (p> 0,05). Il volume medio dell'innesto virtuale era di 2.184 mm3 (quattro denti mancanti), 1,819 mm3 (tre denti mancanti) e 1,476 mm3 (due denti mancanti). In conclusione, l'atrofia dello stadio V era il pattern di riassorbimento più frequente rispetto alle classi IV e V, nelle mandibole posteriori. La procedura di rigenerazione virtuale ha rivelato tre gruppi di innesti virtuali, che differiscono solo per la lunghezza in base al numero di denti mancanti. Si consigliano studi futuri per determinare il rapporto di adattamento tra innesti virtuali e reali alla superficie dell'osso.
1.1. ABSTRACT OBJECTIVES: The aim of this review was to explore the development of soft tissue expanders, their different types and their potential applications prior to bone augmentation and implant placement. MATERIALS & METHODS: A review of pertinent literature was performed using PubMed to comprehend the dynamics of soft tissue expanders and determine the current position of their pre- augmentation applications. RESULTS: There is promising, albeit preliminary information regarding the benefits of pre- augmentation soft tissue expansion (STE). Findings cannot be generalized due to relatively small sample size of the scarce clinical studies available in literature. CONCLUSIONS: Further clinical trials with larger sample sizes and long-term follow-up are needed before soft tissue expanders can be confidently applied in everyday clinical practice. 2.1. ABSTRACT OBJECTIVES: To investigate the clinical outcomes, complications and volume gain of pre-augmentation soft tissue expansion (STE). MATERIALS & METHODS: Tissue expanders were implanted in seven patients requiring vertical and/or horizontal bone augmentation. Guided bone regeneration (GBR) was carried out either after 20, 40 or 60 days of STE. Vertical and horizontal bone gains were analyzed with cone beam computed tomography (CBCT) scans. Optic scanning and superimposition of cast models fabricated from pre- and post- augmentation alginate impressions were used for volumetric analysis. RESULTS: Seven sites in seven patients were treated with STE. Perforation occurred in two sites; early failure due to the tightness of the prepared pouch, and late failure due to minor cracks of the silicon shell covering the expander as a result of handling of the expander body with a dental tweezer. Post-expansion, primary wound closure was easily achieved at augmentation without any subsequent graft expositions. Six months post-augmentation, CBCT analysis revealed high vertical bone gain (mean = 7.3 ± 1.2 mm). Mean of horizontal bone gain was 5.5 ± 2.9 mm. Volumetric analysis of three successful expansion cases revealed a mean volume increase of 483.8 ± 251.7 mm3. Soft tissue volume increase corresponded only to the 0.24 ml cylinder expander (volume increase = 259.4 mm3), while this increase was almost half of the final expander volume for the 0.7 and 1.3 ml cylinder expanders (436.1 mm3 & 755.9 mm3 respectively). Volumetric analysis of the late expansion failure reflected soft tissue shrinkage, which might suggest that STE affects tissues by tension and does not cause real volume gain. All dental implants were osseointegrated in the patients that underwent subsequent dental implant therapy. CONCLUSIONS: High vertical bone gain and minimal post-surgical complications were associated with bone augmentation procedures preceded by soft tissue expansion (STE). 3.1. ABSTRACT To ensure a successful dental implant therapy, presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although post-extraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone-grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone-graft substitutes such as 3D-scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D-scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration. 4.1. ABSTRACT OBJECTIVES: To analyze bone resorption patterns in the posterior mandibles and their corresponding digitally designed bone grafts to understand if they come in distinct clusters. MATERIALS & METHODS: In this retrospective analysis, 120 CBCT scans were analyzed to evaluate the frequency of Cawood & Howell classification, in right and left posterior mandibles. Results were compared between gender and age. The most frequent atrophic class that needs bone augmentation was virtually regenerated in the mandibular segments using specific software. Height, width and length of the obtained grafts were analyzed to conclude if these grafts come in distinct clusters. RESULTS: Class V was the most frequent atrophic class in comparison to class IV & VI in the left and right posterior mandibles (16%, 20.8% respectively). Severe atrophic stages were more frequent in females (p= 0.029 for the left side, p= 0.007 for the right side) and in older age groups (p= 0.008 for the right side) After virtual regeneration of class V defects, three clusters were evident, differing only in length, based on the number of missing teeth (p= 0.0001). Height and width of the virtual grafts were comparable for the three clusters (p > 0.05). Mean virtual graft volume was 2,184 mm3 (four missing teeth), 1,819 mm3 (three missing teeth) & 1,476 mm3 (two missing teeth). CONCLUSIONS: Stage V atrophy was the most frequent resorption pattern in comparison to classes IV & V, in posterior mandibles. Virtual regeneration procedure revealed three clusters of virtual grafts, differing only in the length based on the number of missing teeth. Future studies are recommended to determine the adaptation ratio between virtual and actual grafts to bone surface.

A instalação imediata de implante dental na região de molares é crítica, devido a grande perda óssea e da discrepância entre a espessura da crista alveolar e a plataforma do implante. Laserfototerapia (LFT) auxilia na reparação óssea, portanto pode acelerar a instalação do implante. Vinte pacientes foram selecionados para o estudo. Dez pacientes foram submetidos à LFT com laser de diodo de GaAlAs (808nm) no transcirúrgico de exodontia de molares, imediatamente após, e em 24h, 48h, 72h, 96h, 7 e 15 dias. As irradiações foram aplicadas no modo contínuo, em contato e pontual (100mW, 0,04cm2, 075,0J/cm2, 30s por ponto, 3J por ponto, em 5 pontos). O grupo controle (n=10) recebeu o mesmo tratamento, no entanto, o equipamento estava desligado. Quarenta dias depois, espécimes do tecido formado no interior dos alvéolos foram coletados para posterior análise por microtomografia (microCT) e histomorfometria. Dados de ambos os grupos foram comparados pelo test t de Student, enquanto aqueles das diferentes avaliações microtomográficas foram comparados pelo teste de correlação de Pearson (p<0.05). O volume relativo do osso, bem como a área relativa do osso foram significativamente maiores (p<0.001) no grupo laser do que no controle. No grupo controle houve correlação negativa significativa entre número e espessura de trabéculas, e entre número e separação entre trabéculas (p<0.01); entre espessura e separação das trabéculas a correlação foi positiva (p<0.01). O grupo laser mostrou correlação negativa significante entre número e espessura de trabéculas (p<0.01). A Laserfototerapia acelerou o reparo ósseo. Baseado na correlação de Pearson foi possível inferir que o grupo laser apresentou uma distribuição trabecular mais homogênea, com trabéculas menos espessas e mais numerosas, o que pode propiciar a redução do tempo para a instalação do implante.
The immediate dental implant placement in the molars region is critical, because of the high amount of bone loss and the discrepancy between the alveolar crest thickness and the dental implant platform. Laserphototherapy (LPT) improves bone repair thus could accelerate the implant placement. Twenty patients were selected for the study. Ten patients were submitted to LPT with GaAlAs diode laser (808nm) during molar extraction, immediately after, 24h, 48h, 72h, 96h, 7 and 15 days. The irradiations were applied in continuous wave, in contact and punctual mode (100mW, 0.04cm2, 075,0J/cm2, 30s per point, 3J per point, in 5 points). The control group (n=10) received the same treatment; however with the power of the laser off. Forty days later samples of the tissue formed inside the sockets were obtained for further microtomography (microCT) and histomorphometry analyses. Data of both groups were compared by the Student t test, whereas those from the different microCT parameters were compared by the Pearson correlation test (p<0.05). The relative bone volume, as well as the relative area were significantly higher (p<0.001) in the lased than the control group. In the control group there were negative correlations between number and thickness, and between number and separation of trabecula (p<0.01); between thickness and separation of trabecula the correlation was positive (p<0.01). The laser group showed significant negative correlation between the number and the thickness of trabecula (p<0.01). Laserphototherapy accelerated bone repair. By the Pearson correlation test it was possible to infer that the lased group presented a more homogeneous trabecula configuration, with thin and numerous trabecula, which would facilite the reduction of time for the installation of the implant.

O objetivo deste trabalho foi investigar a influência do enxerto ósseo autógeno particulado no processo de reparo do alvéolo dental de ratos Wistar após exodontia. Os animais foram divididos em grupos controle e experimental. Os ratos controles foram submetidos à intervenção cirúrgica para exodontia do incisivo superior direito apenas, enquanto nos ratos experimentais foram realizadas a exodontia e enxertia óssea no alvéolo dental. A eutanásia dos ratos foi realizada no 5o, 15o, 21o e 28o dias de pós-operatório. As amostras obtidas foram processadas para análise histológica. A densidade de área ocupada por osso foi quantificada por um método de contagem diferencial de pontos e com auxílio de um programa de imagens. Os resultados mostraram que a densidade de área preenchida por tecido ósseo não apresentou diferenças estatísticas em nenhum dos tempos pós-operatórios nos grupos analisados. Concluiu-se que o enxerto ósseo autógeno não promoveu um aumento significativo da neoformação óssea no alvéolo dental após exodontia.
After tooth extraction a continuous bone resorption of the alveolar process is observed in the maxilla and in the mandible. The unfavorable anatomy of the reabsorbed bone ridge limits the rehabilitation of the edentulous area with prostheses over dental implants. Filling the dental alveolus after the exodontia with bone grafts and/or biomaterials is a procedure that tries to delay the physiologic resorption of the alveolar process and stimulates bone formation. The aim of this study is to investigate the influence of the particulated autogenous bone graft in the alveolar socket healing following tooth extraction in Rattus Norvegicus Albinus lineage Wistar. Sixty-seven male rats were used, each weighing 190 to 250 g. The animals were divided in a control and an experimental group. The upper right incisor was extracted in the rats of both groups. Following the tooth extraction, in the animals of the experimental group, the socket was grafted with particulated autogenous bone. The bone graft was obtained from the iliac bone of the same grafted animal. At 7, 14 and 21 days of postoperative, some rats received subcutaneous applications of the ossification marker calcein dissolved in a sodium bicarbonate 2% solution. The euthanasia of the animals was accomplished in the 5th, 15th, 21st and 28th days of postoperative. After the euthanasia the bone parts that contain the dental socket of each right maxilla were removed and reduced to small samples. All the samples were then fixed and processed for histological analysis. The total area of bone was quantified in the socket by a differential point-counting method and by use of an image analyzing program. The data were analyzed statistically and showed that there was a progressive increase of the bone total area during the postoperative periods. However, the morphometric analysis of the total area of bone in the control and experimental groups, did not show a significant statistical difference in none of the postoperative periods. The results reveal that the autogenous bone graft did not promote a significant increase of the bone new formation in the dental socket following tooth extraction.

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Objetivo:Avaliar a atuação do E2 durante a regeneração alveolar, utilizando a expressão das proteínas OPG, RANK e RANKL como indicadores celulares de predisposição à reabsorção ou formação de tecido ósseo. Material e métodos: Após 8 dias da cirurgia SHAM ou ovariectomia (OVX), as ratas (200g) OVX receberam implantes subcutâneos contendo óleo de milho (grupo OVX/óleo) ou E2 (400μg) (grupo OVX/E2). As exodontias dos incisivos superiores direitos foram realizadas no decorrer do tratamento e agendadas para que ao término de 60 dias fosse possível obter as peças referentes a 14, 28 e 42 dias de regeneração óssea alveolar. As peças foram submetidas a processamento imunoistoquímico. Resultados: Nos animais com ciclo estral regular (grupo SHAM), foi observada expressão baixa aos 14, média/alta aos 28 e a não expressão de OPG e RANKL aos 42 dias. A expressão de RANK iniciou alta e foi diminuindo até o último período analisado. No grupo OVX/Óleo a expressão de RANKL foi crescente até o término da análise aos 42 dias, enquanto que a expressão de RANK diminuiu ao longo do período estudado. Foi observada expressão de OPG no início e ao final do período analisado. Os animais OVX/E2 apresentaram marcação semelhante para OPG, RANK e RANKL aos 14 dias. A expressão de RANKL foi observada até o final do experimento, entretanto não foi detectada expressão de OPG e RANK aos 28 e 42 dias. Conclusão: Estes resultados evidenciam a participação do E2 modulando o ciclo de remodelação óssea alveolar.
Objective: To evaluate the role of E2 during alveolar bone regeneration, using OPG, RANK and RANKL protein expression as cellular indicators of predisposition to resorption or bone tissue formation. Methods: Eight days after either SHAM surgery or ovariectomy (OVX), the OVX rats (200g) received subcutaneous implants with corn oil (OVX/oil group) or E2 (400μg) (OVX/E2 group). Extraction of the maxillary right incisors were performed during the course of the treatment and was scheduled in such a way that at the end of a 60-day period it would possible to retrieve anatomic pieces referring to 14, 28 and 42 days of alveolar bone healing. The pieces were submitted to immunohistochemical processing. Results: In the animals with regular estrous cycle (SHAM group), it was observed low expression at 14 days, medium/high expression at 28 days and no OPG and RANKL expression at 42 days. RANK expression started high and decreased continuously up to the last analyzed period. In the OVX/oil group, RANKL expression increased up to the completion of the analysis at 42 days, whereas RANK expression decreased within the studied period. OPG expression was observed in the beginning and the end of the analyzed period. The animals OVX/E2 showed similar labeling for OPG, RANK and RANKL at 14 days. RANKL expression was observed up to the end of the experiment. However, no OPG and RANK expression was detected at 28 and 42 days. Conclusion: These results demonstrate the role of E2 modulating the alveolar bone remodeling cycle.

INTRODUCTION During the three-year doctoral period, the candidate developed 3 research projects which, although different, are all related to one of the most controversial topics of advanced implant dentistry which include procedures to make it possible the use of dental implants also in case of severely atrophic edentulous ridges. During the last decade, a variety of surgical procedures have been proposed, each of them with specific indications, contraindications, advantages and disadvantages. Despite the publication of numerous systematic reviews and meta-analyses focused on this fascinating topic, much controversy is still present between clinicians and researches. The aims of the PhD candidate have been to focus on three main areas related to the correction of severely atrophic edentulous ridges in order to: 1) update the present knowledge on this particular field thank to a systematic analysis of the available literature; and 2) develop three different research projects specifically dedicated to regeneration/reconstruction procedures. More in detail, one line of research was focused on the evaluation of medium to long-term results of dental implants placed in severely atrophic jaws reconstructed with autogenous calvarial bone blocks covered with bovine bone mineral and collagen membranes. Seventy-two patients and 330 implants were involved in this retrospective study with a mean follow-up after implant loading of 8 years, ranging from 3 to 19 years. The second project, similar in structure to the previous one, was designed to evaluate retrospectively the medium and long-term results (with a mean follow-up of 10 years) of implants placed in atrophic edentulous ridges grafted with autogenous mandibular blocks covered with bovine bone mineral and collagen membranes. Seventy-five patients, 82 sites, and 182 implants were involved in this study. The third line of research allowed the candidate to design a prospective study which involved edentulous and atrophic patients treated with guided bone regeneration using CAD-CAM customized titanium meshes. The effectiveness of digitally customized titanium meshes in association with autologous bone particles and bovine bone mineral for the regeneration of atrophic edentulous sites, and the survival rate of implants placed in the reconstructed areas were evaluated. A histomorphometric analysis of mandibular regenerated bone were also performed. Forty-one patients, 53 sites, and 106 implants were involved in this study and the follow-up of implants before and after loading ranged from 2 to 23 months (mean: 11 months), and from 1 to 15 months (mean: 6 months), respectively. This latter research is of particular interest, as the literature supporting this particular technique is scarce, and available data are difficult to be compared, because they have been collected in a non- systematic way and mainly retrospectively. In all these studies, a dedicated questionnaire, adapted from the OHIP-14 survey, was performed to evaluate patients’ satisfaction (patient reported outcome measurements – PROMs) as regards the treatment received. It was therefore possible to elaborate a discussion of the results on two different levels: the first associated to the specific regenerative / reconstructive technique; the second allowed a comparison among the different treatment solutions. AIMS The aim of the first and second project, two retrospective longitudinal cohort studies, is to present the medium to long-term outcome of bone reconstructions with calvarium or mandibular grafts , respectively by evaluating: a) complication rate of the reconstructive procedure; b) bone resorption before implant placement; c) peri-implant bone resorption; d) implant-related complications; e) implant survival rate; and, f) patient’s satisfaction inquired with a dedicated questionnaire. The aims of the third project, a prospective, single-arm clinical study, are to evaluate: a) the effectiveness of digitally customized titanium meshes in association with autologous bone particles and BBM and covered with collagen membranes for the regeneration of atrophic edentulous sites; b) the survival rate of implants placed in the regenerated areas and, c) PROMs inquired with a dedicated questionnaire. MATERIALS & METHODS Project 1 – calvarium From 1998 to 2014, 72 patients presenting with severe bone defects were reconstructed with autogenous calvarial bone blocks covered with bovine bone mineral granules and collagen membranes. Four to 9 months later, 330 implants were placed and loaded 3 to 9 months later. The follow-up ranged from 3 to 19 years (mean: 8.1 years). Project 2 – ramus from 1997 to 2015, 75 patients presenting with bone defects of the jaws were grafted with autogenous mandibular bone blocks. One-hundred-eighty-two implants were placed 4 to 12 months later and loaded 3 to 10 months later: the mean follow-up was 10 years (range: 3-16 years). Project 3 – GBR with Ti-mesh 41 patients, presenting with 53 atrophic sites were enrolled between 2018 and 2019. GBR was obtained with titanium meshes filled with autogenous bone chips and bovine bone mineral (BBM). After a mean of 7 months (range: 5-12 months), meshes were removed and 106 implants placed. After a mean of 3.5 months (range: 2-5 months), implants were uncovered and prosthetic restorations started. RESULTS Project 1 – calvarium No patients developed severe complications, such as complete loss or resorption of the grafts. A dehiscence occurred in 6 patients, which developed a mild graft resorption. The mean peri-implant bone resorption before implant placement was 0.13 mm (SD ± 0.71). All patients received the planned number of implants. Three patients were lost during the follow-up. The survival rate of implants at the end of the observation period was 98.5%. The mean peri-implant bone resorption ranged from 0.00 mm to 4.87 mm (mean: 1.11 mm). Finally, 90% of the patients were very satisfied as regards the treatment received. Project 2 – ramus Post-operative recovery was uneventful in the majority of patients. An early dehiscence occurred in three patients, but with no significant bone loss, while 3 experienced temporary paresthesia. The mean vertical and horizontal bone resorption before implant placement was 0.18 mm (standard deviation (SD)=0.43) and 0.15 mm (SD=0.42), respectively. The mean peri-implant bone loss ± standard deviation was 1.06±1.19 (range 0.00 to 5.05) at patient level, and 1.11±1.26 (range 0.00 to 5.20) at implant level. Two implants in 2 patients lost integration and were removed; 10 implants in 7 patients developed peri-implantitis, but healed after surgical treatment. The cumulative implant survival and success rates were 98.11% and 85.16%, respectively. PROMs were very positive: 95.5% of patients would have undergone the procedure again. Project 3 – GBR with Ti-mesh out of 53 sites, 11 underwent mesh exposure: 8 of them were followed by uneventful integration of the graft, while 3 by partial bone loss. The mean vertical and horizontal bone gain after reconstruction was 4.78±1.88mm (range 1.00 to 8.90mm), and 6.35±2.10mm (range 2.14 to 11.48 mm), respectively. At the time of implant placement, mean changes of initial bone gain were -0.39±0.64mm (range -3.1 to +0.80mm), and -0.49±0.83mm (range –3.7 to +0.4mm), in the vertical and horizontal dimensions, respectively. Reduction of bone volume was significantly higher (P<0.001 for both dimensions) in the exposed sites. At histologic analysis, mesh appeared well osseointegrated, except that in sites where membrane exposure occurred. In all sites, newly formed tissue resulted highly mineralized, well-organized and formed by 35.88% of new lamellar bone, 16.42% of woven bone, 10.88% of osteoid matrix, 14.10% of grafted remnants and 22.72% of medullary spaces. Blood vessels were the 4 % of the tissue.The mean follow-up of implants after loading was 10.6±6.5months (range: 2 to 26months). The survival rate of implants was 100%. PROMs were very positive: 92.5% of patients would have undergone the procedure again. DISCUSSION These three projects have offered, on one side, a relevant opportunity to evaluate the short, medium, and long-term outcomes of both reconstructions with autogenous bone blocks and guided bone regeneration with an innovative, customized, titanium mesh. On the other side, “intrinsic” methodologic limits have appeared during the development of this PhD thesis, such as: o heterogeneity of patient samples and type of defects; o retrospective and prospective type of study; o duration of the observation period; o presence/absence of evaluation of bone gain and with different methods; o different methods used to evaluate bone resorption before implant placement. Despite these limits, results from these three researches offered relevant information as regards the behaviour of the transplanted /regenerated bone as well as the behaviour of peri-implant bone over time. Although the three projects significantly differ among them as regards details in the reconstructive procedures, it must be underlined that many aspects are in common. Therefore, to reduce redundancies it has been decided to write a “unified” discussion which will make it possible a direct comparison of pros, cons, indications and contra-indications of each of them. More in detail, each of the following issues will be discussed reporting and comparing obtained from each study: 1. bone gain; 2. complication rate of the reconstructive procedure; 3. bone resorption before implant placement; 4. peri-implant bone resorption; 5. survival rate of implants and implant-related complications; 6. patient’s satisfaction inquired with a dedicated questionnaire. CONCLUSION Despite the descriptive nature of the first two retrospective longitudinal cohort studies and the variability of the selected patients (including different patients anamnesis, defects locations, defect morphologies, and prosthetic rehabilitations), medium- to long-term results seem to confirm the efficacy of reconstruction of atrophic ridges using autogenous bone blocks taken from both the calvarium and the mandibular ramus covered by a protective layer of bovine bone mineral and stabilized by a collagen membrane. The use of autogenous calvarial grafts may be prefer in case of severely deficient edentulous ridges, when the ramus can offer an insufficient quantity of bone. The low postoperative morbidity, the stability over time of the augmented bone, the high survival rate of implants placed in a prosthetically driven way, leading to very satisfactory prosthetic restorations, confirmed the long-term reliability of these procedures. Preliminary results of the third prospective study, on the other hand, despite the limited number of patients, implants, short follow-up, and the non-negligible incidence of Ti-mesh exposures, seem to demonstrate that CAD-CAM customized Ti-meshes may represent a reliable GBR option for the correction severely atrophic edentulous ridges in terms of vertical bone gain, limited peri-implant bone resorption and survival rate of implants. It is however worth noting that if on one hand it is possible to simplify the reconstructive procedure thanks to the customization of Ti-meshes, on the other hand surgeons have to face the non-negligible incidence of Ti-mesh exposures and the higher complexity of their removal at the time of implant placement. Therefore, studies involving a higher sample of patients and with longer follow-ups are necessary. PROMs seem to validate the use of all the regenerative and reconstructive procedures, with high value of patient’ satisfaction.

Several factors, including periodontal disease, can lead to alveolar bone reabsorbtion. The aim of this study was to investigate and compare the efficiency of mononuclear bone marrow cells (MN-BMC) associated with hydroxiapatite with hydroxiapatite alone, to promote bone regeneration. The dogs were separated in two groups (GI and GII) of nine animals. A defect of 4,3 mm diameter was surgically induced by a trephine bur between the dental roots of the fourth pre-molar tooth. In each dog the wound was treated with FMCB associated with HA (GII) or HA alone (GI). Bone marrow was extracted from all four members, the surgical access for this procedure consisted in the major tracanter of the femur and humerus condyle. In order to process the bone marrow a Histopaque® 1.077 gradient was used to separate the layer of mononuclear cells. A small sample of this layer was used for verification of total cell count and viability. The obtained mononuclear cells were then transplanted to the patients as soon as possible. Clinical evaluations for 7 days, radiologic examinations at 14, 45 and 60 days, and histological analyzes at 14, 45 and 60 days were made in order to investigate and compare the efficiency of the treatments in bone regeneration and/or reparation. The surgical procedure was adequate for the investigation purpose and the trephine bur permitted standardization of the bone defects. Adequate cell number and viability were obtained from the four bone marrow extractions followed by their processing. Scarring of the surgical wound was satisfactory and occurred similarly for the two groups. Both groups presented similar progress by radiological examination. Immediate postsurgical exams indicated that the bone defect had an adequate fulfillment. At 14 days, radiopacity had diminished when compared with immediate post-surgical finding; this was followed by an increase in radiopacity at 45 days, in both groups. Even though bone defect was still visible, radiopacity at 60 days was higher than that of 45 days. Histological evaluation indicated a progressive bone formation process in both groups. Immature bone was already visualized at 14 days in GII. In fact, histological and statistical analyzes provide reliable data that bone regeneration occurred in a less amount of time in GII at a probability of 5%. HA was still present at the 60 day group evaluation witch indicates that this biomaterial had not been completely absorbed at this time. Additionally, foreign body reactions were not present proving that the bone grafts used was biocompatible. In summary, this study has shown that the use of MN-BMC in combination with HA resulted in improvement in bone reparation when compared with HA alone.
Vários fatores, dentre eles a doença periodontal, podem levar à reabsorção do osso alveolar. O presente trabalho teve como objetivo avaliar a fração total de células mononucleares (FTCM) proveniente da medula óssea (MO) na regeneração alveolar da mandíbula de cães, quando associadas à hidroxiapatita sintética (HA). Para isso, foram utilizados 18 cães divididos em 2 grupos (GI e GII). No GI o defeito foi preenchido somente com o biomaterial. O GII foi tratado com HA associado à FTCM. Defeitos de 4,3 mm de diâmetro foram criados entre as raízes do quarto pré-molar direito no osso alveolar. Esses foram preenchidos com o implante correspondente a cada grupo. A MO foi coletada dos quatro membros do animal. O acesso para a coleta no membro pélvico foi o trocanter maior do fêmur, já o acesso no membro torácico consistiu no côndilo maior do úmero. Da MO coletada, foi extraída a camada mononuclear por meio de centrifugação em gradiente de Histopaque® 1.077. As células mononucleares foram transplantadas logo após separação. Com a finalidade de investigar e comparar a eficiência da regeneração óssea foi realizado avaliações clínicas diárias durante uma semana; avaliações radiográficas no pós-operatório imediato, aos 14, 45 e 60 dias; e exames histológicos aos 14, 45 e 60 dias. A cicatrização da ferida ocorreu de forma satisfatória e semelhante para ambos os grupos. O exame radiográfico revelou evolução semelhante para os dois grupos. No pós-operatório imediato, esse exame, permitiu avaliar o adequado preenchimento do defeito no GI e GII. Nos dois grupos, aos 14 dias, observou-se uma diminuição da radiopacidade,em relação ao pós-operatório imediato, seguida por um aumento na mesma aos 45 dias em relação aos 14 dias. Essa evolução é esperada em um processo de reparação ósseo onde é usado como a HA. A radiopacidade aos 60 dias foi superior daquela observada aos 45 dias, mas o defeito ainda era perceptível. Os exames histológicos indicaram um processo de formação ósseo progressivo nos dois grupos. Aos 14 dias, havia presença de trabéculas ósseas no GII, não sendo observadas no GI nessa data. De fato, o GII apresentou um processo de regeneração óssea mais acelerada em relação ao GI até os 45 dias, sendo comprovado estatisticamente pela presença em maior quantidade de matriz óssea no GII aos 45 dias, ao nível de significância de 5%. Ainda era perceptível a presença da HA em algumas amostras aos 60 dias indicando que essa não foi completamente reabsorvida. Nenhuma reação do tipo corpo estranho foi observada, portanto, comprovando a biocompatibilidade do material. Coletivamente, os resultados obtidos neste trabalho mostraram que a associação da FTCM provenientes da medula óssea de cães à HA favoreceu a regeneração óssea em defeitos realizados no osso alveolar da mandíbula de cães. Quando comparada ao uso somente da hidroxiapatita sintética, esse processo de regeneração ocorreu de forma mais rápida em defeitos preenchidos com o biomaterial associado à FTCM.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Esta pesquisa avaliou o efeito do uso local do residronato de sódio, em diferentes concentrações molares, no processo de reparação de defeitos ósseos em fêmures de ratas. Foi confeccionado no fêmur de 60 ratas um defeito ósseo medindo 2,5 mm de diâmetro. Estes animais foram divididos em grupos: controle (C), amido (Am), residronato 0,25 mol (Res 0,25), residronato 0,5 mol (Res 0,50), residronato 0,75 mol (Res 0,75) e residronato 1 mol (Res 1), de acordo com o material de preenchimento utilizado. Nos animais do grupo controle o defeito ficou preenchido apenas pelo coágulo. Os animais foram eutanasiados aos sete e 21 dias, e o fêmur foi removido, fixado e descalcificado, para a confecção de lâminas histológicas. Foram realizadas análises histológica e histomorfométrica, e os dados obtidos foram submetidos à análise estatística ANOVA. Histologicamente, as principais diferenças ocorreram após 21 dias. Os grupos C e Am apresentaram fechamento em extensão do defeito ósseo em todos os espécimes e a maioria dos animais dos grupos tratados com residronato em diferentes concentrações molares não exibiu neoformação óssea na região central do defeito, permanecendo este preenchido por tecido conjuntivo. Nos períodos de sete e 21 dias não houve diferença estatística significante entre os grupos C e Am em relação a neoformação óssea. Estatisticamente, não houve diferença entre os grupos Res 0,25; Res 0,50; Res 0,75 e Res 1 no período de sete dias. Já no período de 21 dias o grupo Res 0,25 apresentou a maior média, mas não diferiu estatisticamente do grupo Res 0,75. Concluiu-se que o residronato de sódio em todas as concentrações molares, prejudicou a reparação óssea nesse modelo experimental. No entanto, foi observada uma neoformação óssea extra-cortical subperiosteal nos grupos que receberam residronato.
This work evaluated the action of sodium residronate, in different molars concentrations, in the repair of bone defects in femurs of rats. A bone defect measuring 2,5 mm in diameter was made in the femur of 60 rats. These animals were divided in groups: control (C), starch (Am), residronate 0,25 mol (Res 0,25), residronate 0,50 mol (Res 0,50), residronate 0,75 mol (Res 0,75), residronate 1 mol (Res 1), in accordance with the material of fill used. In the animals of the control group, the defect was just filled by the clot originating from the defect. The animals were euthanized at seven and 21 days, when the femur was removed, fixed and decalcified, to make histologicals laminae. Histological and histomorphometric analyses were performed and the results obtained were submitted to statistical analysis ANOVA. Histologically, the principal differences occurred after 21 days. The groups C and Am, showed an extension closure of bone defect in every specimen and most animals in groups treated with residronate in different molar concentrations did not show bone neoformation in the central region of the bone defects, which remained filled with connective tissue. After seven and 21 days, there was no significant statistical difference among groups C and Am in relation to bone neoformation. Statistically, there were no differences among the groups Res 0,25; Res 0,50; Res 0,75 e Res 1 in the period of seven days. In the period of 21 days, the group Res 0,25 had the highest average, but did not differ statistically from the Res 0,75. It was concluded that the sodium residronate in all the molar concentrations, harmed the bone repair in this experimental model. However, there was an extracortical subperiosteal bone neoformation in groups receiving residronate.

Orientador: Paulo Sérgio Perri de Carvalho
Resumo: Foi realizado um estudo retrospectivo para avaliar os resultados da reconstrução do processo alveolar intensamente reabsorvido com diferentes tipos de enxerto ósseo autógeno associados à instalação de implantes simultâneos e mediatos (após 4 meses da instalação do enxerto) realizados no período de 4 anos e 6 meses. Foram selecionados para este estudo 84 pacientes, submetidos à reconstrução de defeitos ósseos dos maxilares, com enxertos ósseos do mento, linha oblíqua da mandíbula, crista ilíaca anterior e calota craniana, com um total de 346 implantes instalados, sendo que, 257 destes implantes encontravam-se, com as próteses implantossuportadas instaladas, e distribuídos em 40 implantes simultâneos e 217 mediatos. Desta forma, foram avaliadas os transtornos de técnica cirúrgica e as complicações relacionadas com as áreas receptoras, bem como a taxa de sobrevivência dos implantes. De acordo com os resultados obtidos, dentre alguns dos transtornos de técnica cirúrgica e complicações estavam a redução da quantidade de mucosa ceratinizada na cortical vestibular e conseqüente perda da profundidade de sulco, assim como, exposição parcial do enxerto, contaminação do enxerto, entre outras complicações verificadas. A taxa de sobrevivência, obtida para os implantes simultâneos e mediatos instalados, foi de 94,55%. Quando a taxa de sobrevivência foi avaliada individualmente para cada grupo, no caso dos implantes simultâneos foi encontrado um resultado de 97,50%, enquanto que para os implantes mediatos obteve-se um resultado de 94,10%%. Portanto com este estudo, conclui-se que dos transtornos de técnica cirúrgica com maior ocorrência estava a redução da quantidade de mucosa ceratinizada sobre a crista do rebordo, complicações como exposição parcial do enxerto entre outras, que as áreas doadoras intrabucais oferecem vantagem...(Resumo completo, clicar acesso eletrônico abaixo)
Abstract: A retrospective study was carried out in order to evaluate the outcomes of the reconstruction of the severely resorbed alveolar ridge through different types of autogenous bone grafts associated to the placement of simultaneous and delayed implants (4 months after the bone graft procedure) accomplished during a period of 4 years and 6 months. A total of 84 patients were selected for the present study, which were submitted to reconstruction of the bone defects of the jaws by means of bone grafts from the chin, external oblique ridge, anterior iliac crest, cranial vault, adding up to 346 implants, from which 257 (40 simultaneous and 217 delayed implants), with the installed implant-supported prostheses. The evaluation concerned of the overturn of surgical technique and complications related to the receptor sites, as well as the survival rate of the implants. The results indicated occurrence of the overturn of surgical technique and complications such as reduction in the amount of keratinized mucosa over the buccal cortical plate with consequent decrease in vestibular depth, as well as partial exposure of the graft, contamination of the graft, and others. The survival rate for both simultaneous and delayed implants was 94.55%. Regarding the individual evaluation of each group, the simultaneous implants demonstrated a survival rate of 97.50% in relation to 94.10% for the delayed implants. The most frequent of the overturn of surgical technique were reduction in the amount of keratinized mucosa over the alveolar ridge, complications as partial exhibition of the graft among others, better performance of the intraoral donor sites in relation to the extraoral sites, positive association between implant failures and iliac crest grafts, besides significantly worse outcomes for the female subjects in relation to the males. Better results were observed for the simultaneous implants, what is in disagreement with previous studies.
Doutor

Study background: Recent advances in 3D radiological techniques and virtual planning softwares allow the clinician to visualize simultaneously the anatomy of the patient and the prosthetic wax-up directly within the digital environment. This enables ideal planning of the correct position of dental implants considering at the same time anatomical structures and prosthetic demands. The virtual project is then transferred to the surgical site by means of stents realized on the basis of the virtual project. Implants are finally inserted with a computer-guided approach in the desired positions. So far, this technique has been safely used in anatomical situations presenting an adequate amount of bone so that bone augmentation procedures can be avoided and an adequate implant positioning can be achieved. Aim: The purpose of the present proof-of-concept study was to evaluate the effectiveness of computer-guided implant placement associated to computer-aided guided bone regeneration (GBR) in critical anatomical situations presenting less than ideal quality and quantity of supporting bone to receive dental implants in a prosthetically-driven position. Materials and methods: Healthy non-smoking patients seeking a fixed rehabilitation were enrolled if presenting partial edentulism characterized by atrophic alveolar bone in the posterior sectors of maxilla or mandible. Patients underwent conebeam computed tomography (CBCT) exam and impression of the edentulous space was scanned optically. Data of the two acquisitions were imported and matched within dedicated software. At this point, it was possible to plan the ideal position of the implants in a prosthetically-driven position according to a virtual wax-up. The missing bone was virtually augmented according to the position of the implants and the anatomy of the residual alveolar ridge. The project was transferred to the surgical environment by means of stereolithographic model fitted with the augmented bone and tooth-supported guide. Prior surgery, a dense-expanded-polytetrafluoroethylene (d-e-PTFE) membrane was trimmed and contoured based on the said model. Under local anesthesia on outpatient basis, a full thickness flap was raised and implants were inserted with a computer-aided fully-guided approach. Subsequently, the alveolar ridge was augmented by grafting autogenous bone particles harvested nearby the surgical site with a bone scraper and deproteinized bovine bone mineral (DBBM) granules in a 1:1 ratio. The graft was covered with previously shaped d-e-PTFE membrane fixed with osteosynthesis screws to the underlying bone. A first intention healing was accomplished with horizontal mattresses and single stitches. The duration of the surgery was registered in minutes. Patients were given a questionnaire reporting visual analogue scales (VASs) used to self-register postoperative pain, swelling, bleeding, and perception of the operation during the first post-operative week. Follow-up recalls were scheduled to clinically and radiographically evaluate the post-operative course. Post-operative CBCT scan was acquired to superimpose the position of the implant obtained during the surgical procedure with that planned in the virtual project. The aim was to evaluate the accuracy in terms of linear and angular deviations. To this end, a control group consisting of implants placed with a computer-aided fully-guided approach by means of mucosa-supported screw-retained surgical guides in fully edentulous patients served as reference point. After 6 months from the surgical procedure, the re-entry surgery was carried out to clinically evaluate the quality and quantity of augmented bone. After testing for normality assumption, parametric and non-parametric statistical tests were used to explore the study variables. The significance threshold was set at 0.05. Results: Overall, 11 patients were considered eligible and were consecutively enrolled and treated, of which 5 in the test group (2 males and 3 females), and 6 in the control group (5 males and 1 female). The mean age was 52.2 ± 6.41 years in the test group, and 60.17 ± 12.73 years in the control group (p = 0.238). The mean surgical duration was 92 minutes. No intra- and post-operative complications occurred during the entire study period. Only one patients exhibited a dehiscence of the lingual flap with d-e-PTFE membrane exposure. This was related to an erroneous management of the lingual flap during the surgery, a fact that was not attributable to the experimental procedure itself. Nevertheless, at the re-entry surgery all patients showed complete filling of the bone defect with no clinical and radiological signs of infection or resorption. The newly formed bone-like tissue appeared well vascularized and integrated within the recipient bone. In some cases, implants were completely covered by the regenerated hard tissue. No early losses were observed. In regards to patient-centered outcomes, pain scored exceptionally high with respect to the other variables. The peak was observed at 2 days post-operatively (mean VAS = 64.4 ± 5.17). Swelling peaked the third post-operative day (mean VAS = 56.4 ± 8.14), while the peak of bleeding was registered after 1 day from the surgical procedure (mean VAS = 16.2 ± 2.58). As expected, all variables decreased significantly from their respective peaks up to the seventh post-operative day (p < 0.05). The mean VAS score for the patients’ perception of the operation was 36 ± 8.63, with no significant correlation with the variables analyzed (p > 0.05). A total of 10 and 38 implants in the test and control group respectively were available for the accuracy assessment. No statistically significant differences could be found with respect to linear deviation at coronal and apical points and angular deviation of the long-axis among groups. Mean differences between the two groups were 0.04 ± 0.32 mm; 0.02 ± 0.35; and 0.27° ± 1.71° respectively (p > 0.05). Conclusions: Within the limitations of the present study, computer-guided implant placement and simultaneous computer-aided bone augmentation yielded encouraging results in terms of efficacy and accuracy. No intra- and post-operative complications were observed, therefore the procedure can be considered safe and predictable with respect to surgical and biological aspects at least on a short-term basis. On the other hand, patient-centered outcomes were below the expectations. Further studies are needed to evaluate survival, success, and complication rates of both implants and prostheses on a long-term basis.

Objetivo: o objetivo deste ensaio clínico controlado aleatorizado foi avaliar o uso de um substituto ósseo sintético associado a uma membrana de colágeno absorvível na preservação da crista óssea alveolar após extração dentária, por meio de análises clínica e tomográfica em humanos. Metodologia: Quatorze pacientes foram selecionados, cada um apresentando ao menos dois dentes anteriores maxilares indicados para extração: no Grupo Teste (GT), o alvéolo pós-exodontia foi preenchido pelo substituto ósseo sintético Reprobone, e no Grupo Controle (GC) houve o preenchimento do alvéolo apenas por coágulo. Em ambos os grupos os alvéolos foram cobertos por uma membrana absorvível de colágeno (BioMend), que por sua vez foi recoberta por um retalho mucoperióstico fechado oclusivamente. Tomografias computadorizadas do tipo Cone Beam foram realizadas no pós-operatório imediato e após 6 meses do procedimento cirúrgico, e as alterações dimensionais horizontais e verticais das cristas ósseas foram quantificadas. Para a análise estatística intragrupo utilizou-se o teste t pareado; para avaliações intergupo, teste t não pareado. Em todas as comparações foi adotado um nível de significância de 5%. Resultados: A Medida Vertical Vestibular reabsorveu 1,5 mm (ou 21,3%) da medida inicial no Grupo Teste (p<0,05) e 1,8 mm (ou 25,8%) no Grupo Controle (p<0,05). A Medida Vertical Palatina diminuiu 0,3 mm em ambos os grupos (p>0,05). A Altura Máxima reduziu 0,5 mm ou 7,9% no grupo com Reprobone e BioMend quando comparada ao baseline (p>0.05), e 1,1 mm ou 14,8% no grupo com BioMend apenas (p<0,05), sendo esta diferença intergrupo estatisticamente significante (p<0,05). A Medida Horizontal Apical diminuiu 0,2 mm no GT, o equivalente a 2,9% (p>0,05), enquanto que no GC diminuiu 0,5 mm ou 7,3% (p<0,05), não havendo diferença estatisticamente significante entre os grupos. A Medida Horizontal Cervical (MHC) perdeu 0,5 mm ou 7,2% no GT e 1,4 mm ou 15,1 % no GC: a análise intragrupo apontou diferença estatística entre os dados iniciais e após 6 meses para este parâmetro (p<0,05), em ambos os grupos, e também foi encontrada diferença estatisticamente significante na avaliação entre grupos para a MHC. Conclusão: Os resultados obtidos demonstraram que o uso do Reprobone associado à Biomend apresentou benefícios e melhores resultados na manutenção vertical e horizontal do rebordo alveolar em comparação ao uso apenas da membrana colágena.
Objective: The aim of this randomized controlled clinical trial was to evaluate the use of a synthetic bone substitute associated with an absorbable collagen membrane in preserving the alveolar crest after tooth extraction, through clinical and tomography analysis in humans. Methods: Fourteen patients were selected, each featuring at least two front teeth jaws indicated for extraction: in Test Group (TG), the post-extraction sockets were filled by the synthetic bone substitute ReproBone, and the control group (CG) was filling the alveoli only by clot. In both groups, the wells were covered with a resorbable collagen membrane (BioMend), which in turn was covered with a mucoperiosteal flap closed occlusally. CT Cone Beam type were performed in the immediate postoperative period and after 6 months of surgery, and the horizontal and vertical dimensional changes of the bone crests were quantified. For intra-group statistical analysis used the paired t test; to intergupo reviews, unpaired t test. In all comparisons was adopted a 5% significance level. Results: Vestibular Vertical Measure reabsorbed 1.5 mm (or 21.3%) of the original measure in the test group (p <0.05) and 1.8 mm (or 25.8%) in the control group (p <0 , 05). The Measured Vertical Palatine 0.3 mm decreased in both groups (p> 0.05). The Maximum Height reduced 0.5 mm or 7.9% for the ReproBone and BioMend compared to baseline (p> 0.05), and 1.1 mm or 14.8% for the BioMend only (p <0.05 ), statistically significant intergroup difference (p <0.05). Measure the horizontal apical decreased by 0.2 mm WG, equivalent to 2.9% (p> 0.05), whereas the CG 0.5 mm or decreased by 7.3% (p <0.05), not statistically significant difference between groups. The Horizontal Cervical Measure (MHC) lost 0.5 mm or 7.2% in GT and 1.4 mm or 15.1% of CG: the intra-group analysis showed statistical difference between the initial data and after 6 months for this parameter (p <0.05) in both groups, and was also a statistically significant difference between groups in the evaluation for the MHC. Conclusion: The results showed that the use of ReproBone associated with BioMend presented benefits and better results in vertical and horizontal maintenance of alveolar ridge compared to using only the collagen membrane.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A altura insuficiente do osso alveolar é um fator limitante para a reabilitação oral com próteses implantossuportadas. Taxas de sucesso clínico com uso de biomateriais à base de beta-tricálcio fosfato (b-TCP) para elevação do assoalho do seio maxilar (EASM) mostraram que são excelentes alternativas ao osso autógeno (OA). Portanto, objetivo foi avaliar a formação óssea do enxerto de b-TCP em bloco, seis meses após EASM, comparada ao OA por meio de análises tomográfica, microtomográfica e histomorfométrica. Para isso, Oito seios maxilares foram enxertados com b-TCF e sete OA. Após 6 meses, foram obtidas biópsias durante à instalação de implantes dentários. Não houve diferença significante (ANOVA) entre a contração do volume dos seios maxilares preenchidos por OA e b-TCP (p=0,113), bem como para todos os parâmetros microtomográfico (ANOVA) BV/TV (p=0.089), Tb.Th (p=1.000), Tb.Sp (p=0,989) e Tb.N (p=0.917). Na histomorfometria quando comparada a porcentagem ósseo em OA e b-TCP também não foi encontrada diferença estatística (ANOVA, p=0,794). Em conclusão, os resultados deste estudo indicam que ambos OA e b-TCP são adequados para o uso com segurança para o procedimento de EASM pela técnica da janela lateral. O material sintético apresenta boa estabilidade volumétrica com formação óssea semelhante ao OA suportada pelos parâmetros em análises 2D e 3D que se complementam. No entanto, a metodologia da análise volumétrica utilizada neste estudo parece representar a estabilidade volumétrica geral do procedimento, não somente do biomaterial, quando na técnica for utilizado o enxerto em bloco e não particulado.
The insufficient height of the alveolar bone is a limiting factor for oral rehabilitation with implants. Clinical success rates using beta-tricalcium phosphate (b-TCP) biomaterials for maxillary sinus floor elevation (MSFE) have been shown to be excellent alternatives to autogenous bone (AB). Therefore, the objective was to evaluate bone formation of the b-TCP graft in a block, six months after MSFE, compared to AB by means of tomographic, microtomographic and histomorphometric analyzes. For this, eight maxillary sinuses were grafted with b-TCF and seven AB. After 6 months, biopsies were obtained during the installation of dental implants. There was no significant difference (ANOVA) between the volume contraction of the maxillary sinus filled by AB and b-TCP (p = 0.113), as well as for all microtomographic parameters (ANOVA) BV/TV (p = 0.089), Tb.Th (p = 1.000), Tb.Sp (p = 0.989) and Tb.N (p = 0.917). In histomorphometry, when comparing bone percentage in AB and b-TCP, no statistical difference was found (ANOVA , p = 0.794). In conclusion, the results of this study indicate that both AB and b-TCP are suitable for safe use for the MSFE procedure by the side window technique. The synthetic material presents good volumetric stability with bone formation similar to AB supported by the parameters in 2D and 3D analyzes that complement each other. However, the volumetric analysis methodology used in this study seems to represent the general volumetric stability of the procedure, not only of the biomaterial, when in graft and non-particulate graft technique.

Orientador: Horácio Faig Leite
Banca: Vanessa Ávila Sarmento Silveira
Banca: Luiz Eduardo Blumer Rosa
Resumo: Esta pesquisa avaliou o efeito do uso local do residronato de sódio, em diferentes concentrações molares, no processo de reparação de defeitos ósseos em fêmures de ratas. Foi confeccionado no fêmur de 60 ratas um defeito ósseo medindo 2,5 mm de diâmetro. Estes animais foram divididos em grupos: controle (C), amido (Am), residronato 0,25 mol (Res 0,25), residronato 0,5 mol (Res 0,50), residronato 0,75 mol (Res 0,75) e residronato 1 mol (Res 1), de acordo com o material de preenchimento utilizado. Nos animais do grupo controle o defeito ficou preenchido apenas pelo coágulo. Os animais foram eutanasiados aos sete e 21 dias, e o fêmur foi removido, fixado e descalcificado, para a confecção de lâminas histológicas. Foram realizadas análises histológica e histomorfométrica, e os dados obtidos foram submetidos à análise estatística ANOVA. Histologicamente, as principais diferenças ocorreram após 21 dias. Os grupos C e Am apresentaram fechamento em extensão do defeito ósseo em todos os espécimes e a maioria dos animais dos grupos tratados com residronato em diferentes concentrações molares não exibiu neoformação óssea na região central do defeito, permanecendo este preenchido por tecido conjuntivo. Nos períodos de sete e 21 dias não houve diferença estatística significante entre os grupos C e Am em relação a neoformação óssea. Estatisticamente, não houve diferença entre os grupos Res 0,25; Res 0,50; Res 0,75 e Res 1 no período de sete dias. Já no período de 21 dias o grupo Res 0,25 apresentou a maior média, mas não diferiu estatisticamente do grupo Res 0,75. Concluiu-se que o residronato de sódio em todas as concentrações molares, prejudicou a reparação óssea nesse modelo experimental. No entanto, foi observada uma neoformação óssea extra-cortical subperiosteal nos grupos que receberam residronato.
Abstract: This work evaluated the action of sodium residronate, in different molars concentrations, in the repair of bone defects in femurs of rats. A bone defect measuring 2,5 mm in diameter was made in the femur of 60 rats. These animals were divided in groups: control (C), starch (Am), residronate 0,25 mol (Res 0,25), residronate 0,50 mol (Res 0,50), residronate 0,75 mol (Res 0,75), residronate 1 mol (Res 1), in accordance with the material of fill used. In the animals of the control group, the defect was just filled by the clot originating from the defect. The animals were euthanized at seven and 21 days, when the femur was removed, fixed and decalcified, to make histologicals laminae. Histological and histomorphometric analyses were performed and the results obtained were submitted to statistical analysis ANOVA. Histologically, the principal differences occurred after 21 days. The groups C and Am, showed an extension closure of bone defect in every specimen and most animals in groups treated with residronate in different molar concentrations did not show bone neoformation in the central region of the bone defects, which remained filled with connective tissue. After seven and 21 days, there was no significant statistical difference among groups C and Am in relation to bone neoformation. Statistically, there were no differences among the groups Res 0,25; Res 0,50; Res 0,75 e Res 1 in the period of seven days. In the period of 21 days, the group Res 0,25 had the highest average, but did not differ statistically from the Res 0,75. It was concluded that the sodium residronate in all the molar concentrations, harmed the bone repair in this experimental model. However, there was an extracortical subperiosteal bone neoformation in groups receiving residronate.
Mestre

Introdução: A regeneração óssea guiada baseia-se no princípio de seletividade celular, utilizando membranas para impedir a migração de células indesejadas dos tecidos moles e guiar a proliferação de células osteogênicas. A MDA é um biomaterial que tem sido amplamente utilizado em procedimentos regenerativos periodontais, não somente por ser biocompatível, mas também pela sua capacidade reconstrutiva em proporcionar um aumento da faixa de tecido queratinizado. Em pesquisas recentes, foi demonstrado o envolvimento de uma cadeia de 15 aminoácidos do colágeno (P-15) na diferenciação celular de fibroblastos e osteoblastos. A associação de matriz óssea inorgânica bovina com o P-15 (MOI/P-15) tem apresentado bons resultados. O objetivo dessa pesquisa foi avaliar a eficácia da MDA associada à MOI/P-15 na preservação da crista alveolar após extração dentária em humanos. Metodologia: Foram selecionados 18 pacientes que necessitavam de exodontia de dentes anteriores da maxila com pelo menos dois dentes não contíguos. Foi adotado o modelo boca dividida. Após as extrações dentárias foram realizadas cirurgias regenerativas de preservação da crista alveolar utilizando MOI/P-15 (GT) em um alvéolo e o coágulo sanguíneo no outro alvéolo (GC). Após a inserção do substituto ósseo, a MDA foi posicionada e fixada com parafusos sobre os dois alvéolos para servir como membrana. O retalho foi suturado deixando 2 mm da MDA expostos na porção central. As medidas clínicas MVEP, MVEV e MAH foram registradas na primeira cirurgia e após 6 meses, na cirurgia de reentrada, tomando-se como pontos de referência os parafusos de titânio. Resultados Na análise intragrupos, após seis meses, houve redução estatisticamente significante nas medidas MVEP, MVEV e MAH para ambos os grupos. Para o grupo teste, houve redução na MVEP de 2,80 ± 1,61 para 1,97 ± 1,67 mm; na MVEV de 5,80 ± 1,74 para 4,60 ± 2,05 mm e na MAH de 7,40 ± 2,16 para 4,87 ± 1,51 mm. Para o grupo controle, a MVEP variou de 2,50 ± 1,24 para 1,63 ± 1,32 mm; a MVEV de 6,27 ± 1,75 para 4,77 ± 1,59 mm e MAH de 7,60 ± 1,18 para 4,20 ± 1,00 mm. Para a comparação entre os grupos, além das medidas iniciais e finais, foram calculadas as diferenças entre elas para cada grupo. No grupo teste, a diferença para MVEP foi de 0,83 ± 1,53 e no controle foi de 0,87 ± 1,13 mm; e para MVEV foi de 1,20 ± 2,02 e 1,50 ± 1,15 mm para os grupos teste e controle, respectivamente. Na medida horizontal (MAH) foi encontrada diferença estatística quando comparadas as diferenças no grupo teste e controle que foi de 2,53 ± 1,81 mm para o grupo teste e 3,40 ± 1,39 mm para o grupo controle (p<0,05). Conclusão: Os resultados deste estudo mostram que a MDA, associada ou não a MOIP-15, pode ser utilizada com sucesso como membrana para preservação do rebordo alveolar após extração dentária de dentes maxilares anteriores. A associação com o enxerto favorece de maneira significativa a manutenção da espessura no sentido horizontal da crista alveolar.
Background: Preventing ridge collapse with the extraction of maxillary anterior teeth is vital to an esthetic restorative result. Several techniques are available to regenerative procedures and are used for socket preservation. The aim of this study was to analyze by clinical parameters the use of acellular dermal matrix (ADM) and anorganic bovine bone matrix (ABM) with a synthetic cell-binding peptide P-15 to preserve alveolar bone after tooth extraction. Methods: Eighteen patients in need of extraction of maxillary anterior teeth were selected and they were randomly assigned to the test (ADM plus ABM/P-15) or control (ADM only). Clinical measurements were recorded at initial and 6 months after ridge preservation procedures. Results: In the clinical measurements - External Vertical Palatal, External Vertical Buccal and Alveolar Horizontal (EVPM, EVBM and AHM) -, the statistical analysis showed no difference between test and control groups in the initial and at six months. The intragroup analysis, after six months, showed a statistically significant reduction in the measurements for both groups. In the comparison between the groups, the differences (mm), in the test group, were: EVLM=0.83±1.53, EVBM=1.20±2.02, AHM=2.53±1.81 and in the control were: EVLM=0.87±1.13, EVBM=1.50±1.15, AHM=3.40±1.39. The differences in EVLM and EVBM measurements were no statistically significant; however, in horizontal measurement (AHM), there was statistically difference (p<0.05). Conclusion: The results of this study show that ADM, with or without ABM/P-15, can be successfully when it is used as a membrane for preservation of alveolar ridge after tooth extraction of maxillary teeth earlier.

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
Os procedimentos de Regeneração Óssea Guiada (ROG) visam fornecer ao paciente melhoras, a nível estético e funcional, aumentando o volume e disponibilidade óssea. Actualmente realizam-se procedimentos para aumento do rebordo ósseo com o intuito de possibilitar a colocação de implantes dentários e melhorar a sua estética. Será descrita nesta revisão bibliográfica a Regeneração Óssea Guiada (ROG) para aumento vertical do rebordo alveolar e posterior colocação de implantes, bem como a previsibilidade da técnica e as suas taxas de sucesso. Existem vários materiais disponíveis para a técnica de ROG vertical, porém as membranas de politetrafluoroetileno expandido não-reabsorvível (PTFE-e) com reforço de titânio em associação com enxerto (1:1) autógeno e mineral de osso bovino desproteinizado (DBBM) constituem, actualmente, a primeira escolha quando se pretende o aumento ósseo vertical. A ROG para aumento vertical, apresenta boas taxas de sucesso e previsibilidade, contudo necessita de um operador com experiencia pois é uma técnica de muita exigência. Esta técnica pode ser realizada prévia ou em simultâneo com a colocação dos implantes.
Guided Bone Regeneration (GBR) procedures aim to provide the patient with aesthetical and functional improvements, increasing the bone volume and availability. Currently, procedures to increase the bone ridge are undertaken with the objective of allowing the placement of dental implants and improve their aesthetical appeal. Guided Bone Regeneration (GBR) for the vertical augmentation of the alveolar ridge and consequent implant placement will be described in this bibliographical review, as well as the predictability of the technique and its success rates. There are several materials available for the vertical GBR technique, however the membranes of expanded non-resorbable polytetrafluoroethylene (PTFE-e) with titanium reinforcement in association with autogenous graft (1:1) and deproteinized bovine bone mineral (DBBM) currently represent the first choice when a vertical bone augmentation is intended. The GBR for vertical augmentation features good success rates and predictability, however it requires an experienced operator, as it is a demanding technique. This can be performed previously or simultaneously with the placement of implants.

Periodontium is a complex system of different tissues, such as connective tissue, cartilage and bone, which work together to sustain the tooth. Gingivitis and periodontitis are devastating diseases that could affect the structure and function of the periodontal tissue. When the gingivitis are not treated and controlled with a correct oral hygiene, they could evolve in periodontitis, which could seriously damage the tissue surrounding the tooth and lead tooth loss. The main objective of periodontal tissue engineering is to regenerate the tooth’s supporting tissues. Periodontal tissue regeneration involves formation of new connective tissue (cementum and periodontal ligament) and new alveolar bone. The restoration of tooth by using a titanium dental implant is nowadays a quite common procedure. However, the positive fate of a surgical procedure that involves an insertion of titanium screw depends on the quality and quantity of alveolar bone which is present in the extraction site. The main objective of this doctoral thesis is to develop a set of novel biomaterials, designed to improve periodontal bone regeneration in patients and to control or prevent the bacterial infection in the wound site, via a sustained in situ drug release. Three different materials have been developed and characterized: 1. Three-dimensional porous scaffold coated with a polyelectrolyte complex for periprosthetic infection prevention 2. Bioceramic-reinforced hydrogel for alveolar bone regeneration 3. Antiadhesive guided tissue regeneration membrane The results demonstrated that they could be used in periodontal tissue engineering with predictable and excellent outcomes. With this set of biomaterials it is possible to control or prevent possible bacterial growth, achieve the correct alveolar bone quantity and quality and guide the tissue regeneration

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The use of dental implants is a common practice in human patients, and the demand for this service in small animals has increased in the last years. For the placement of dental implants it is necessary the existence of an alveolar bone bed of good quality and in enough quantity. Several factors such as periodontal disease and dental loss can cause reabsorption of the alveolar bone, thus enabling the placement of these implants. The objective of this work was to evaluate, through clinical, radiographic and histological analyses, the bioglass as a bone substitute in the regeneration of the alveolar process of the jaw of dogs. For such, 28 healthy adult mongrel dogs, males and female, weighing between 10 and 15 Kg, randomly divided in two groups, were observed during 120 days. Defects of approximately 6 x 5 x 5 mm were created in the vestibular surface of the alveolar process between the roots of the right fourth premolar tooth. In a group, the defect was immediately filled with bioglass, while in the other it did not receive any treatment, being used as control. Clinical evaluations were accomplished daily during one week. Radiographies were taken soon after the surgery and at 8, 14, 21, 42, 60, 90 and 120 days of the postoperative. Most of the animals of both groups did not present inflammation signs and the healing of the surgical wound happened in a similar way. The radiographic exams revealed gradual increase of the radiopacity in the area of the defect in the control group. In the treated group, it was initially observed superior radiopacity compared to the neighbor bone, which decreased on the 21st day of postoperative. Then the radiopacity began to gradually increase until 120 days after the surgery, when the defect became imperceptible. For the histologic analysis samples of the bone defect area of 2 animals of each group were collected after 8, 14, 21, 42, 60, 90 and 120 days of the surgery. In the control group it was observed that the bone deposition process began on the day 14th, developing progressively until the day 120th, when there was not limit between the margins of the defect and the neoformed bone. In the treated group it was observed at 8 days of postoperative the presence of loose connective tissue highly vascularizated around the bioglass particles. At 14 days, it was observed the bone formation process starting from the borders of the defect. On the 60th day of postoperative the bioglass had been totally reabsorbed and the defect was completely filled by trabecular bone. At 120 days, it was not possible to differentiate the neighbor bone of the defect area. Therefore, it can be concluded that the bioglass presents desirable characteristics to a bone substitute such as antibacterial and hemostatic effect, biocompatibility and osteoconductive property, being a valuable alternative for the alveolar bone regeneration.
A utilização de implantes dentários é prática comum em humanos, e a demanda por este serviço em animais de estimação tem aumentado nos últimos anos. Para o emprego de implantes dentários é necessário a existência de um leito de osso alveolar de boa qualidade e em quantidade suficiente. Vários fatores tais como a doença periodontal e a perda dentária podem levar à reabsorção do osso alveolar, impedindo a colocação destes implantes. O objetivo deste trabalho foi avaliar, por meio de análises clínico-cirúrgica, radiográfica e histológica, o biovidro como substituto ósseo na regeneração do processo alveolar da mandíbula de cães. Para tal, foram utilizados 28 cães adultos clinicamente saudáveis, machos e fêmeas, pesando entre 10 e 15 kg, divididos aleatoriamente em dois grupos iguais e observados durante 120 dias. Foram criados defeitos de aproximadamente 6 x 5 x 5 mm na superfície vestibular do processo alveolar entre as raízes do dente quarto pré-molar direito. Em um grupo, o defeito foi imediatamente preenchido com biovidro, enquanto no outro este permaneceu sem preenchimento, sendo utilizado como controle. Foram realizadas avaliações clínicas diariamente durante uma semana, assim como radiografias logo após a cirurgia e aos 8, 14, 21, 42, 60, 90 e 120 dias do pós-peratório. A maioria dos animais dos dois grupos não apresentou sinais de inflamação e a cicatrização da ferida cirúrgica ocorreu de forma semelhante. O exame radiográfico revelou aumento gradual da radiopacidade na região do defeito no grupo controle. No grupo tratado, observou-se inicialmente radiopacidade superior à do osso vizinho, com diminuição desta até os 21 dias de pós-operatório, voltando a aumentar gradativamente até os 120 dias do pós-cirúrgico, quando a falha tornou-se imperceptível. Aos 8, 14, 21, 42, 60, 90 e 120 dias do pós-operatório também foram coletadas amostras da região da falha óssea de 2 animais de cada grupo para a análise histológica. Observou-se que no grupo controle o processo de deposição óssea iniciou-se aos 14 dias, evoluindo progressivamente até que aos 120 dias não havia mais limite entre as margens do defeito e o osso neoformado. Já no grupo tratado observou-se logo aos 8 dias de pós-operatório a presença de tecido conjuntivo frouxo altamente vascularizado ao redor das partículas de biovidro. Aos 14 dias iniciou-se o processo de formação óssea a partir das bordas da falha, até que aos 60 dias o biovidro havia sido totalmente reabsorvido e o defeito apresentava-se completamente preenchido por osso trabecular. Aos 120 dias, não foi mais possível diferenciar o osso vizinho da região da falha. Portanto, pode-se concluir que o biovidro apresenta características desejáveis a um substituto ósseo tais como efeito antibacteriano e hemostático, biocompatibilidade e propriedade osteocondutora, sendo uma alternativa viável quando objetiva-se a diminuição do tempo de reparação do osso alveolar.

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The periodontal therapies have as objectives not only to stop the progression of the disease, by the interruption of the inflammatory action of the bacterial plate, but also to make possible the restoration of the lost structures, especially as for the maintenance of the architecture and the functional state of those. Thus, the obtained treatments as regenerative or reconstrutivos present as a purpose the formation of new insertion tissues (cement, periodontal linking and alveolar bone) in the involved area by the periodontopaty. Examples of regenerative periodontal therapies include bone grafts and guided tissue regeneration (GTR). The objective of this work was to evaluate the mineralized bovine bone matrix as a substitute bone in the alveolar repairing of the jaw of dogs and its association with a collagen membrane a following the technique of the guided tissue regeneration (GTR). For such, 48 dogs were used, divided in three groups. Defects of approximately 6 x 5 x 5 mm were created among the roots of the fourth right premolar in the vestibular surface of the alveolar bone. In a group, those defects were totally filled out with the xenograft, and in another group, the defect was totally filled out with the xenograft and covered by the membrane, while in the last group, they stayed without treatment, being used as control. Daily clinical evaluations were accomplished for one week, as well as radiographic soon after the surgery and to the 7, 14, 21, 30, 42, 60, 90 and 120 days. The cicatrization of the surgical wound happened in a satisfactory and similar way among the dogs of the three groups. The radiographic exam revealed a slower repairing in the control group, where to the 120 days the defect was still visualized, in comparison with the group treated with the mineralized bovine bone matrix, than to the 60 days was not observed anymore and in comparison with the group treated with the mineralized bovine bone matrix and collagen membrane, than to the 90 days the failure was not visualized anymore. Therefore, it can be concluded that the used materials presented desirable characteristics as biocompatibility and property osteoconductor, being viable alternatives in the aid of the alveolar bone repairing. It was collected, from two animals of each group, material for biopsy of the operated ranch at the 7, 14, 21, 30, 42, 60, 90 and 120 days and histological evaluations were accomplished. In the control group, the bone formation process began at the 14th day and it developed progressively until the 120th day, when the limit between the periphery of the flaw and the new formed bone was not more distinguishable. In the group treated only with the mineralized bovine bone matrix, right at seventh it was observed abundant cellularity around the material and the beginning of the repairing process, that it had already filled out the whole produced defect at the 60 th day. Besides, no reaction of the strange body type was observed and, therefore, it can be concluded that the used material presents desirable characteristics to a substitute bone as biocompatibility and property osteoconductor, being an alternative for the aid of the alveolar bone repairing. In the group treated with the mineralized bovine bone matrix and collagen membrane, a more advanced repairing process was observed in relation to the control group until the 42 th day. Then, a chronic inflammatory process was observed, until the 120 th day, taking it to a repairing bone stagnation. In spite of that, no reaction of the strange body type was observed and, therefore, it can be concluded that the used materials present biocompatibility, desirable characteristic to substitute bone and that the membrane, starting from the 42 th day, provokes undesirable reaction.
As terapias periodontais têm como objetivos não apenas estacionar a progressão da doença, pela interrupção da ação inflamatória da placa bacteriana, mas também possibilitar a restauração das estruturas perdidas, especialmente quanto à manutenção da arquitetura e estado funcional dessas. Assim, os tratamentos tidos como regenerativos ou reconstrutivos apresentam como finalidade a formação de novos tecidos de inserção (cemento, ligamento periodontal e osso alveolar) na área envolvida pela periodontopatia. Exemplos de terapias periodontais regenerativas incluem enxertos ósseos e regeneração tecidual guiada (RTG). O objetivo deste trabalho foi avaliar a matriz óssea bovina mineralizada como substituto ósseo na reparação alveolar da mandíbula de cães e sua associação com uma membrana de colágeno seguindo a técnica da regeneração tecidual guiada (RTG). Para tal, foram utilizados 48 cães, divididos em três grupos. Defeitos de aproximadamente 6 x 5 x 5 mm foram criados entre as raízes do quarto pré-molar direito na superfície vestibular do osso alveolar. Em um grupo, esses defeitos foram totalmente preenchidos com o xenoenxerto, em outro grupo, o defeito foi totalmente preenchido com o xenoenxerto e coberto pela membrana, enquanto no último grupo, permaneceram sem tratamento, sendo utilizados como controle. Foram realizadas avaliações clínicas diárias por uma semana, assim como radiográficas logo após a cirurgia e aos 7, 14, 21, 30, 42, 60, 90 e 120 dias. A cicatrização da ferida cirúrgica ocorreu de forma satisfatória e semelhante entre os cães dos três grupos. O exame radiográfico revelou uma reparação mais lenta no grupo controle, onde aos 120 dias o defeito ainda foi visualizado, em comparação ao grupo tratado com a matriz óssea bovina mineralizada, que aos 60 dias não foi mais observado e em comparação ao grupo tratado com a associação matriz óssea bovina mineralizada e membrana de colágeno, que aos 90 dias a falha não foi mais visualizada. Portanto, pode-se concluir que os materiais utilizados apresentam características desejáveis como biocompatibilidade e propriedade osteocondutora, sendo alternativas viáveis no auxílio da reparação óssea alveolar. Foi coletado, de dois animais de cada grupo, material para biópsia do sítio operado aos 7, 14, 21, 30, 42, 60, 90 e 120 dias e foram realizadas avaliações histológicas. No grupo controle, o processo de formação óssea se iniciou aos 14 dias e evoluiu progressivamente até os 120 dias, quando não foi mais distinguível o limite entre a periferia da falha e o novo osso formado. No grupo tratado somente com a matriz óssea bovina mineralizada, logo ao sétimo dia observou-se abundante celularidade ao redor do material e o início do processo de reparação, que aos 60 dias já havia preenchido todo o defeito produzido. Além disso, nenhuma reação do tipo corpo estranho foi observada e, portanto, pode-se concluir que o material utilizado apresenta características desejáveis a um substituto ósseo como biocompatibilidade e propriedade osteocondutora, sendo uma alternativa para o auxílio da reparação óssea alveolar. No grupo tratado com a associação matriz óssea bovina mineralizada e membrana de colágeno, observou-se o processo de reparação mais avançado em relação ao grupo controle até os 42 dias. Depois, observou-se um processo inflamatório crônico, até os 120 dias, levando a uma estagnação dessa reparação óssea. Apesar disso, nenhuma reação do tipo corpo estranho foi observada e, portanto, pode-se concluir que os materiais utilizados apresentam biocompatibilidade, característica desejável a substitutos ósseos e que a membrana, a partir dos 42 dias, provoca reação indesejável.

The purpose of this prospective, randomized, controlled clinical investigation is to evaluate the performance of the Motorized Ridge Expanders (MRE), and to compare its results with the ones achieved utilizing lateral ridge augmentation (LRA). Eight subjects with bilateral ridge deformities were selected. One technique was used on the right site and the other on the left site. Implants were placed six months after the bone augmentation procedures. All the measurements were recorded at 2 and 5 mm from the most coronal part of the crest. The augmentation achieved with both techniques was statistically significant, 1.2 mm in the LRA, 1.5 mm in MRE at 2 mm from the crest; 1.5 mm and 1.6 mm respectively at 5mm from the crest. The differences between the two techniques were statistically insignificant. The amount of expansion achieved in the MRE site appears to be negatively correlated (P-Value <0.05) with the thickness of the cancellous bone, and it is not affected by the thickness of the cortical plate. The MRE technique appears to be as effective as the LRA technique in augmenting the thickness of atrophic ridges. The defect treated with the MRE showed less bone width contraction during the first 6 months of healing. Histologically, the regenerated bone was vital, trabecular in nature and in direct contact with bone graft particles.
El propósito de esta investigación clínica prospectiva y aleatoria es comparar el aumento horizontal de la cresta alveolar obtenido con el uso de los expansores motorizados de cresta (EMC) y con regeneración ósea guiada (ROG). Fueron selecccionados ocho pacientes con deformidades horizontales del reborde alveolar bilaterales que iban a recibir implantes dentales. Una técnica de regeneración se utilizó en el lado derecho y la otra en el lado izquierdo, para un total de 23 muestras, 13 en el lado experimental (EMC) y 10 en el lado control (ROG). Los implantes fueron colocados seis meses después de los procedimientos de aumento óseo, y se obtuvo una muestra de hueso para estudio histológico. Todas las mediciones clínicas se registraron a los 2 y 5 mm de la parte más coronal de la cresta. El aumento logrado con ambas técnicas fue estadísticamente significativo, de 1,2 mm en la ROG y 1,5 mm con los EMC a 2 mm de la cresta; y 1,5 mm y 1,6 mm, respectivamente, a 5mm de la cresta. Las diferencias entre las dos técnicas no fueron estadísticamente significativas. La cantidad de expansión lograda en el sitio de los EMC parece tener una correlación negativa (p <0,05) con el grosor del hueso esponjoso, y no se ve afectada por el grosor de la cortical. Histológicamente se observó osteoconductividad del injerto óseo y más partículas residuales del mismo en el lado experimental. La técnica de los EMC parece ser tan eficaz como la técnica de ROG en el aumento de la anchura de las crestas atróficas. Los defectos tratados con los EMC mostraron una menor contracción del injerto óseo durante los 6 meses de cicatrización.
El propòsit d'aquesta recerca clínica prospectiva i aleatòria és comparar l'augment horitzontal de la cresta alveolar obtingut amb l'ús dels expansors motoritzats de cresta (EMC) i amb regeneració òssia
guiada (ROG). Es van selecccionar vuit pacients amb deformitats horitzontals bilaterals de la cresta alveolar on es col.locaren implants dentals. Una tècnica de regeneració es va emprar en el costat dret i l'altra a la banda esquerra, per a un total de 23 mostres, 13 al costat experimental (EMC) i 10 en el costat control (ROG). Els implants van ser col.locats sis mesos després dels procediments d'augment ossi, i es va obtenir una mostra d'os per estudi histològic.Totes les mesures clíniques es van registrar als 2 i 5 mm de la part més coronal de la cresta. L'augment aconseguit amb ambdues tècniques va ser estadísticament significatiu, de 1,2 mm a la ROG i 1,5 mm amb els EMC a 2 mm de la carena, i 1,5 mm i 1,6 mm, respectivament, a 5mm de la cresta. Les diferències entre les dues
tècniques no van ser estadísticament significatives. La quantitat d'expansió aconseguida en el lloc dels EMC sembla tenir una correlació negativa (p<0,05) amb el gruix de l'os esponjós, i no es veu afectada per el gruix de la cortical. Histològicament es observar osteoconductividad l'empelt ossi i més partícules residuals d'aquest en el costat experimental. La tècnica dels EMC sembla ser tan eficaç com la tècnica de ROG en l'augment de l'amplada de les crestes atròfiques. Els defectes tractats amb els EMC mostrar una menor contracció de l'empelt ossi durant els 6 mesos de cicatrització.

碩士
國立臺北科技大學
化學工程與生物科技系生化與生醫工程碩士班
105
According to statistics compiled by the Ministry of Health and Welfare of Taiwan, Taiwan has the highest population ratio of periodontal disease in Asia. If people have not a good health habits of oral and regular inspection will lead to bacterial plaque formation; further invade to the cementum, periodontal ligaments and alveolar bone, will eventually lead to loose teeth and fall off. When patients with severe alveolar bone damage can not be prosthetic rehabilitation, autologous bone graft is widely considered as the gold standard for the treatment of the bone reconstruction, it can avoid immune response, but the risk of second surgery may cause morbidity in the donor site. The most important, the limited source of tissue that can be obtained. Therefore, in vitro reconstruction and regeneration of alveolar bone tissue research is an urgent issue, but the development of suitable for clinical use and functional organization is still quite difficult challenges. In this study, we establish a strategy, which combines Ca-Alginate scaffolds and rat bone marrow stem cells (bm-MSCs), for bone-like tissues formation. We had developed the self-designed bioreactor system previously, in vitro to three-dimensional dynamic culture of bone-like tissue to carry out autologous alveolar bone graft. This technology mainly uses the Ca-Alginate scaffolds to provide three-dimensional growth environment, porous structure helps nutrient permeability, bone-like tissue formation, without any enzyme treatment can be collected, bioreactor simulation of the human circulatory system , closed reflux system not only help cell proliferation and differentiation, but also to cell secretion of growth factors and cytokines can be fed back to the cells in culture, and reduce the incidence of human pollution. The self-designed bioreactor system is cost-effective and able to reduce the risk of contamination. We can get enough bone-like tissues cultivated in vitro under high-throughput process in the closed-loop system. In the future, we hope this technology can provide another choice for patients and clinical doctors.

碩士
國立臺灣大學
醫學工程學研究所
101
With the global prevalence of periodontitis which leads to irreversible bone loss, the regeneration of bone tissue poses a challenge to engineers and clinicians. The importance of alveolar bone cannot be overemphasized since it is one of the tooth-supporting structures. In the past few years, the research of growth factor for alveolar bone regeneration is blooming, but still remains controversial due to its instability and high cost. Instead of using growth factors, we hypothesized that cells could be recruited from extracellular matrix for bone repair by collagenase treatment without any autologous grafts. Hence, the purpose of this study is to evaluate the bone regenerative capacity after the implantation of hydroxyapatite and calcium sulfate (gypsum) with hyaluronic acid carrying collagenase in the rat model. In the study, the setting time, compressive strength, release characteristics and biocompatibility of Hyaluronic acid/Collagenase/Hydroxyapatite/Calcium sulfate were evaluated. The potential for reconstruction of destroyed alveolar bone by the implanted composite was also tested in rat model. The initial setting time of the composite was 21 minutes which is adequate for clinicians to handle. The compressive strength of composites after immersion in phosphate buffered saline solution in 7 days was 6.5MPa, and decreased after 2 weeks. The release profile shows 60 % of collagenase incorporated in the composite was released in 30 minutes that coincides with the time of collagenase digestion normally used in primary culture. The good biocompatibility of the composite was also confirmed by WST-1 test which indicates no significant difference between control group and experimental group. In animal study, the result of the composite HA/Collagenase/HAP/CS in 12-week after surgery was superior to other groups including commercial product Bio-OssR. Evidence of obvious regeneration in bone defects treated with HA/Collagenase /HAP/CS can be observed in micro-CT images histological results. Then we can conclude that it might be feasible for collagenase treatment to recruit more cells during healing process. In the future, the study can be applied to canines as an animal model for further confirmation.

Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Following a tooth extraction, a cascade of biological events will lead inevitably to a decrease in the height and width of the alveolar ridge, mostly on the buccal side and horizontally. In this sense, given how often this procedure is performed in dental practice, it is pivotal that every clinician is acquainted with these dimensional changes and its possible impact on future oral rehabilitation. Consequently, several treatment modalities, commonly known as Alveolar Ridge Preservation (ARP) are described in the literature and include: socket grafting, with the use of a bone graft material, guided tissue regeneration (GTR), with the use of a barrier membrane and finally guided bone regeneration (GBR) with the use both a bone graft material and a barrier membrane. Currently, there are several options for bone graft materials available to the clinician, comprising autografts, allografts, xenografts and alloplasts, having each its advantages and drawbacks. The biological plausibility regarding the use of these biomaterials is that thanks to biological properties intrinsic to the grafts, the alveolar ridge resorption would decrease. In the past decade, the use of autogenous teeth as a bone graft material has been described with encouraging results, nevertheless, describing distinct preparation protocols prior to the ARP procedure. Therefore, this literature review aims to summarize all the evidence regarding the use of autogenous teeth as a bone graft material in ARP in post-extraction sockets, its several preparation protocols, efficacy and future perspectives.
Após qualquer exodontia, uma série de eventos biológicos conduzem inevitavelmente a uma redução ao nível da altura e largura do rebordo alveolar, principalmente na componente vestibular e horizontalmente. Desta forma, dada a frequência com que este procedimento é realizado na Medicina Dentária, é fulcral que qualquer clínico esteja informado destas alterações dimensionais e possível impacto numa futura reabilitação oral. Consequentemente, diversas opções de tratamento, vulgarmente conhecido como Preservação da Crista Alveolar (PCA) foram descritas incluindo: regeneração óssea, através do uso de um enxerto ósseo, regeneração tecidular guiada (RTG), através do uso de uma membrana barreira e ainda regeneração óssea guida (ROG) com o uso de um enxerto ósseo associado uma membrana barreira. Atualmente, existem diversas opções de enxertos ósseos disponíveis para o clínico, compreendendo autoenxertos, aloenxertos, xenoenxertos e aloplásticos, tendo cada um vantagens e limitações. A plausabilidade biológica destes biomateriais pode ser explicada devido a propriedades biológicas intrínsecas ao enxerto ajudando a minimizar a reabsorção óssea. Na última década, o uso de dente autólogo como substituto ósseo tem sido descrito com resultados encorajadores, contudo, descrevendo protocolos de preparação distintos antes de realizar a PCA. Desta forma, esta revisão de literatura procura resumir a evidência disponível relativamente ao uso de dente autólogo como substituto ósseo na PCA em alvéolos pós-extração, os diversos protocolos de preparação, eficácia e perspetivas futuras.

Trabalho de Projeto do Mestrado Integrado em Medicina Dentária apresentado à Faculdade de Medicina
Introdução: A perda de osso alveolar e tecidos gengivais pode decorrer por extração dentária, doença periodontal, processos infeciosos, entre outros. Daí existir uma importância extrema nas inovações contínuas relativas a técnicas cirúrgicas e compreensão biológica das técnicas de regeneração óssea. A preservação alveolar define-se como qualquer tipo de procedimento que tem como objetivo minimizar as reabsorções ósseas e maximizar a formação de osso dentro do alvéolo. Existem procedimentos pré-operatórios, intraoperatórios (extração atraumática) e técnicas de reconstrução alveolar pós-operatórias, recorrendo à utilização de diversos materiais tanto de origem autógena, endógena (Bancos de osso) ou xenógena (materiais que proporcionam uma matriz em muito semelhante à matriz óssea).Objectivos: O objetivo deste trabalho é elaborar uma revisão sistemática sobre os biomateriais de regeneração e documentar um caso clínico de cirurgia de preservação alveolar com recursos a membranas de PRP.Materiais e Métodos: Elaborou-se a questão PICO e com recurso a base de dados PubMed/Medlina e b-on, procedeu-se à pesquisa para a revisão da literatura. A cirurgia de preservação foi dividida em duas fases. A primeira fase de colheita sanguínea e a segunda fase, fase cirúrgica propriamente dita, na qual se extraiu um dente 14 ao qual estava associado um defeito infraósseo e preencheu-se o alvéolo com recurso ao agregado PRP. Foram realizados controlos aos 5 dias, 8 dias, 4 semanas, 8 semanas e 3 meses.Resultados: Da pesquisa foram selecionados 20 referências bibliográficas. Todas as técnicas reportaram melhorias significativas, no entanto quando comparadas entre si, estas não mostraram diferenças estatisticamente significantes. Relativamente ao caso clínico, a paciente teve uma excelente recuperação com bom preenchimento do alvéolo 2 meses após a cirurgia. Conclusão: Apesar dos resultados satisfatórios, as bases para a seleção de um material em detrimento de outro não são claras nem estão devidamente definidas quanto à sua aplicação nas várias situações clínicas, sendo necessário mais estudos neste sentido. É de salientar os aspetos práticos do PRP, apesar de acrescentar mais passos durante a cirurgia, consiste num preparado proveniente do próprio paciente sendo o risco de transmissão de patogenes inexistente, constituindo uma alternativa de tratamento viável e segura.
Introduction: The loss of alveolar bone and gingival tissues may be due to, for exe,ple, tooth extraction and periodontal disease. So there’s na extreme importance in the continuous innovationsrelated to surgical techniques and biological understanding of the techniques for bone regeneration. Alveolar preservation is defined as a procedure that aims to minimize bone resorption and maximize the formation of bone within the socket. There are many procedures that can be perform before, during or after na extraction, like alveolar reconstrucion. For this, there are several materials available, like autografts, being the choice material with perfect compatibility, endogenous grafts, xenogafts and others materials.Objective: The aim of this work was to elaborate a Sistematic review on biomaterials for bone regeneration and document a curgical case of alveolar preservation with PRP membrans.Materials and methods: PICO question was elaborated and with de use of PubMed/MEDLINE e b-On database, the literature review was carried out. the surgery was divided into 2 phases, the first of blood collection and the second phase or surgical phase, the socket was filled with PRP agregate. Follow-ups were performed at 5 days, 8 days, 4 and 13 weeks.Results: 20 references weres selected for this study. All techniques reported significant improvements, however when compared with each other, they did not show significant diferences. Regarding the clinical case, the patient han na excelente recovery with good filling of the socket, 2 months after surgery.Conclusion: Despite the results, the protocol for the selection of one biomaterial over another is not properly defined in terms of its application in clinical situations, and further studies are necessary. PRP, despite adding more steps during the surgery, consist of a preparation form the patient’s blood, so the risk of transmission of psthogens doesn´t exist, constituting a safe and viable treatment.

Há alguns anos atrás, certos actos clínicos que tinham como finalidade restabelecer a estética dentaria sendo um exemplo os implantes, eram quase impossíveis sem a altura a e espessura óssea suficiente. Hoje em dia, através de um processo de regeneração óssea podemos restabelecer condições suficientes para recuperar ou melhorar a configuração do osso e poder assim realizar a reabilitação com implantes. Existem vários tipos de regeneração tanto horizontal como vertical, neste trabalho vamos estudar e focalizar sobre a regeneração vertical visto esta ser mais difícil de alcançar e exigir uma atualização maior da parte do Médico Dentista na busca pela estabilidade do seu trabalho. (Antoun, H. 2013 ; Karouni, M. 2013 ; Sojod B. 2013) Objectivos : Inicialmente vai ser analisada de forma sucinta a base fisiológica óssea, mais precisamente os mecanismos da remodelação óssea, depois falaremos da regeneração vertical do osso e exploraremos as diferentes técnicas disponíveis para este fim. Por ultimo, destacaremos as indicações, contra-indicações , vantagens e desvantagens de cada uma delas.
A few years ago, certain clinical acts aimed to restoring dental aesthetics, such as implants, were almost impossible without adequate bone height and thickness. Nowadays, through a process of bone regeneration we can restore sufficient conditions to recover or improve the configuration of the bone and thus be able to carry out the rehabilitation with implants. (Antoun, H. 2013, Karouni, M. 2013, Sojod B. 2013). There are several types of regeneration both horizontal and vertical, in this work we will study / we will focus on vertical regeneration. Objectives: First, let's take a brief look at the physiological basis of bone, more precisely the mechanisms of bone remodeling, then we will talk about vertical bone regeneration and explore the different techniques available for this purpose. Finally, we will highlight the indications, contraindications, advantages and disadvantages of each of them.

Please read the abstract in the front section of this document
Dissertation (MChD (Periodontics and Oral Medicine))--University of Pretoria, 2007.
Oral Pathology and Oral Biology
unrestricted

Um enxerto ósseo consiste em levar osso de um local anatômico (local doador) onde é abundante e onde a remoção resultará apenas em consequências mínimas, para coloca-lo noutro local onde o volume ósseo é diminuído (local de recepção) e onde melhorará a estética e / ou a função. No arsenal terapêutico das cirurgias dentárias, um enxerto ósseo é indicado com mais frequência em uma das seguintes situações: Cirurgia reconstrutiva e reconstrutiva facial (sequelas pós-traumáticas, reconstrução das maxilas e contornos do osso facial). Cirurgia pré-implantar onde o enxerto ósseo restaurará um volume ósseo suficiente para acomodar um implante dentário. Cirurgia periodontal onde o enxerto ósseo restaurará um tecido de suporte abundante e normal ao redor do dente. Existem diversos tipos de enxerto ósseo; O autoenxerto é um enxerto ósseo retirado da pessoa que recebe o transplante. O osso é mais frequentemente tomado na mandíbula, perto da área a ser enxertada. Para enxertos maiores, o osso pode ser removido, por exemplo, da crista ilíaca. Existem enxertos de origem externas, o defeito ósseo pode então ser preenchido por diferentes materiais de origem sintética, humana ou animal. O transplante aloplástico é um material sintético, também conhecido como aloplasto, é um substituto ósseo produzido em laboratório. Este material pode ou não permanecer no corpo; Alguns permanecem e se tornam parte do novo osso, enquanto outros se dissolvem, estimulando o crescimento ósseo na área enxertada durante a sua dissolução. O xenoenxerto é um aloenxerto, o que significa que ele não vem da mesma pessoa para quem o transplante é usado. O material ósseo não vem de um ser humano, mas de outras espécies. O mais comumente usado é o xenoenxerto bovino. Isso significa que o material ósseo é retirado de uma vaca (tratada, esterilizada e condicionada naturalmente). O Alo-enxerto humano é um osso humano retirado de uma pessoa (tratado, esterilizado e embalado) e usado como enxerto ósseo para ser implantado em outra pessoa. A escolha será feita de acordo com o volume e posição do site para preencher. Nenhum dos materiais acima mencionados é usado sistematicamente. O cirurgião dá a indicação de acordo com a extensão da reconstrução, valorizando as vantagens e desvantagens de cada um desses materiais.
A bone graft consists of carrying bone from an anatomical site (donor site) where it is abundant and where removal will only result in minimal consequences, to place it in another place where the bone volume is decreased (place of reception) and where it will improve esthetics and / or function. In the therapeutic arsenal of dental surgeries, a bone graft is indicated more frequently in one of the following situations: - Reconstructive and reconstructive facial surgery (post-traumatic sequelae, reconstruction of the jaws and contours of the facial bone). - Pre-implant surgery where the bone graft will restore sufficient bone volume to accommodate a dental implant. - Periodontal surgery where the bone graft will restore an abundant and normal supporting tissue around the tooth. There are several types of bone graft; The autograft is a bone graft taken from the person receiving the transplant. The bone is most often taken in the jaw, near the area to be grafted. For larger grafts, the bone may be removed, for example, from the iliac crest. There are external grafts of origin, the bone defect can then be filled by different materials of synthetic origin, human or animal. Alloplastic transplantation is a synthetic material, also known as alloplast, is a bone substitute produced in the laboratory. This material may or may not remain in the body; Some remain and become part of the new bone, while others dissolve, stimulating bone growth in the grafted area during its dissolution. The xenograft is an allograft, which means it does not come from the same person for whom the transplant is used. The bone material does not come from a human being, but from other species. The most commonly used is bovine xenograft. This means that the bone material is taken from a cow (treated, sterilized and naturally conditioned). Human allograft is a human bone taken from a person (treated, sterilized and packed) and used as a bone graft to be implanted in another person. The choice will be made according to the volume and position of the site to fill. None of the above materials is used systematically. The surgeon gives the indication according to the extent of the reconstruction, valuing the advantages and disadvantages of each of these materials.