Dissertations / Theses on the topic 'Alveolar bone defect'

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.

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.

Objetivo: O propósito deste estudo é avaliar a regeneração óssea nos defeitos alveolares congênitos com proteína morfogenética óssea (rhBMP-2) em membrana de colágeno reabsorvível. Material e Métodos: Vinte e quatro pacientes com fissura labiopalatina completa unilateral, em momento ideal, foram distribuídos ao acaso entre os grupos controle (porção medular de ilíaco) e teste (rhBMP-2 em membrana de colágeno absorvível). Foram avaliados em 6 meses e 1 ano de pós-operatório por meio de radiografias periapicais e tomografias computadorizadas pela escala de Chelsea. Resultados: Encontraram-se índices de sucesso quanto à altura do septo ósseo semelhantes entre os grupos: em 6 meses, na análise radiográfica, 81,82% no controle e 91,67% no teste; em 1ano, 83,33% no controle e 100% no teste; na análise tomográfica, observaram-se 70% no controle e 91,67% no teste em 6 meses, 75% no controle e 100% no teste em 1 ano. Na análise volumétrica, os valores encontrados foram 45,34% de preenchimento ósseo da fissura no grupo controle aos 6 meses e 40,63% no teste, 53,33% no controle e 53,1% no teste em 1 ano. Não houve diferença estatisticamente significante. Conclusão: A rhBMP-2 em membrana reabsorvível de colágeno produziu resultados semelhantes ao enxerto autógeno de medula de crista ilíaca ao reparar defeitos alveolares de fissuras labiopalatinas completas.
Objective: The purpose of this study is to assess the bony regeneration of alveolar clefts using bone morphogenetic protein (rhBMP-2) in a collagen sponge carrier. Material and Methods: Twenty four patients with unilateral complete cleft lip and palate, in the very best moment, were randomly assigned to groups control (iliac crest cancellous bone) and test (rhBMP-2 in an absorbable collagen sponge). They were evaluated 6 months and 1 year postoperative with periapical radiographs and computed tomographs using Chelsea scale. Results: For control group, radiographic examination revealed success index for bone height 81,82% 6 months and 83,33% 1 year postoperative; for test group, findings were 91,67% first control and 100% 1 year. Computed tomograph revealed 70% 6 months and 75% 1 year for control group, 91,67% first control and 100% 1 year for bone height test group. Volume ratios were 45,34% bone filling 6 months and 53,33% 1 year for control group and 40,63% 6 months and 53,1% 1 year for test. There was no statistical significance. Conclusion: rhBMP-2 in a collagen sponge carrier induced bony regeneration close to that from iliac crest cancellous bone to repair complete alveolar clefts.

Proposição: avaliar radiograficamente e histologicamente o comportamento do incisivo inferior de rato frente à realização de uma solução de continuidade em sua porção radicular mediana quanto ao comportamento do tecido pulpar e dos enxertos ósseos alógenos congelados à -80°C e a evolução do seu processo eruptivo dentário em alvéolos quando expostos aos efeitos da ação do ultra-som. Metodologia: estudo experimental in vivo, amostragem randomizada, com um grupo teste e outro controle. Constou de 29 ratos, da espécie Rattus novergicus albinus, linhagem Wistar, machos, divididos em quatro grupos, correspondendo aos tempos de sete, 14, 21 e 45 dias. Em cada grupo, cinco animais foram teste e dois animais foram controle. Em cada animal foi removido, cirurgicamente, o segmento medial do incisivo inferior direito. Entretanto, nos animais do grupo experimental foram realizados enxertos de osso alógeno congelado a -80°C, nos 2,0mm distais do total da cavidade alveolar cirurgicamente obtida com ultra-som.Resultados: aos sete dias observou-se estrutura tecidual desorganizada e ricamente vascularizada em ambos os grupos avaliados e início da integração do enxerto ósseo no grupo teste. Aos 14 dias seguem as mesmas observações descritas aos sete dias com progressão da incorporação do enxerto ósseo. Aos 21 dias, observa-se intensa neoformação óssea, ricamente vascularizada em ambos grupos. Aos 45 dias, existe também uma intensa neoformação óssea alveolar, fechando o alvéolo e a completa integração dos enxertos ósseos. Em todos os grupos observou-se que houve mínimo crescimento do segmento dentário proximal e que o mesmo manteve sua vitalidade pulpar. Conclusão: Após a realização deste estudo foi possível concluir que: o tecido pulpar, contido no segmento proximal manteve sua vitalidade, reagindo na forma de reparação dentinária compatível com o dente humano; o enxerto ósseo alógeno congelado evolui favoravelmente no processo de incorporação a partir de um leito receptor criado no alvéolo dentário e que o incisivo inferior do rato, submetido à odontossecção com ultra-som não seguiu com o processo de crescimento e erupção em seu segmento proximal, podendo estar relacionado com o reparo do alvéolo devido à intensa neoformação óssea, provavelmente por efeito do ultra-som.
Proposition: This study aimed to evaluate, both radiographically and histologically, the behaviour of a rat’s inferior incisive concerning the realization of a continuous solution in its medial radicular portion, regarding the behaviour of the pulpal tissue and allogeneic freezing bone grafts, at –80° C, as well as the evolution in its dental eruptive process in alveoli exposed to ultrasound effects. Methodology: An in vivo experimental study, using randomized samples, including a study group and a control group. Twenty-nine Wistar strain male rats, Rattus novergicus albinus species, divided into 4 groups, corresponding to 7, 14, 21, and 45 days. From each group, five animals were considered as the test group, and two of them as the control group. Each animal had the medial segment of the right inferior incisive surgically removed. However, the animals from the test group underwent allogeneic freezing bone grafts, at –80° C, in a range of 2.0 mm distal of the total alveolar cavity, surgically performed by ultrasound. Results: In seven days a disorganized and well-vascularized tissue structure in both assessment groups as well as the beginning of the integration of the bone graft in the experimental group could be observed. In 14 days similar observations to day 7 and progression in the incorporation of the bone graft were found. In 21 days intense, well-vascularized, bone neoformation was observed in both groups. In 45 days an intense neoformation of the alveolar bone could also be observed, with the closure of the alveolus, and the complete integration of the bone grafts. All groups had a minimum growth of the dental proximal segment, which maintained its pulpal vitality. Conclusion: The study concluded that the pulpal tissue contained in the proximal segment maintained its vitality, providing a reaction compatible with human tooth regarding dental repairing. The allogeneic freezing bone graft evolved favorably in the incorporation process from a receiver layer created inside the dental alveolus. It was also concluded the rat’s inferior incisive which underwent ultrasonic dental cutting did not follow the growth and eruption process in its proximal segment, what might be related to the alveolus repair due to intense bone neoformation, probably caused by the ultrasound effect.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Proposição: A proposta deste estudo foi avaliar por análise histométrica a resposta tecidual óssea de enxerto autógeno coletado por piezocirurgia para o preenchimento de defeitos nas porções cervicais de implantes instalados em tíbias de coelhos. Métodos: Foram instalados 26 implantes em 13 tíbias de coelho, após a estabilidade inicial foram realizados defeitos cervicais por trefinagem, em um grupo foi mantido apenas o coágulo como preenchimento e em outro grupo o defeito foi preenchido por osso autógeno coletado por equipamento piezoelétrico, os animais foram sacrificados após 15 e 30 dias, a análise histométrica das interfaces implante-osso foram realizadas pelo software Image Lab. Resultados: Foi analisado o percentual de extensão linear de contato entre tecido ósseo e implante, a média percentual obtida de contato entre tecido ósseo neoformado e implante foram estabelecidas como médias da área de osso neoformado entre as espiras e contato osso-implante (BIC). Os resultados obtidos foram: no controle de 15 dias, o percentual entre as espiras foi de 65,2% e entre as espiras e contato osso-implante (BIC) de 88,7%. No controle de 30 dias o contato entre as espiras foi na ordem de 65,2% e entre as espiras e contato osso-implante (BIC) de 73,2%. No grupo de enxerto de 15 dias, o osso formado entre as espiras foi de 69,3% e entre as espiras e contato osso-implante (BIC) em 81%, no grupo enxerto 30 dias o osso formado entre as espiras foi de 91,47% e entre as espiras e contato ossoimplante (BIC) 91,56%. Conclusão: o enxerto ósseo autógeno particulado obtido por piezocirurgia apresenta melhor resultado que o coágulo sanguíneo no osso neoformado entre as espiras e no contato osso-implante
Purpose: The purpose of this study was to evaluate by histometric analysis the outcome of autogenous bone collected through piezo surgery equipment in filling cervical portion defects around implants placed in rabbits tibias. Materials and Methods: Twenty-six implants were installed in 13 rabbits tibias, after initial primary stability, cervical defects were carried out by the use of a trephina, in one group the cloth was maintained as the defect filling and in another group the defect was filled by autogenous bone collected through piezo surgery equipment, the animals were sacrificed after 15 and 30 days, the histometric analysis of the implant-bone interfaces were carried out by the use of Image Lab software. Results: The lineal stretch percentage of contact between bone and implant was analyzed, the average percentage obtained in the contact between the newly formed bone and the implant was established as the average area of the newly formed bone in the space between the spires and the bone-implant contact (BIC). The results obtained were: in the 15-days control group, the percentage of bone formation between the spires was of 65.2% and between the spires and boneimplant contact (BIC) was of 88.7%. In the 30-days control group the contact between the spires was of 65.2% and between the spires and bone-implant contact (BIC) of 73.2%. In the 15-days control grafted group, the formed bone between the spires was of 69.3% and between the spires and bone-implant contact (BIC) of 81%, in the 30-days control grafted group, the formed bone between the spires was of 91.47% and between the spires and bone-implant contact (BIC) of 91.56%. Conclusions: the autogenous bone collected through piezo surgery equipment showed better results than the blood clot regarding the newly formed bone between the spires and bone-implant contact (BIC)

Orientador: Idelmo Rangel Garcia Júnior
Banca: Élio Hitoshi Shinohara
Banca: Thallita Pereira Queiroz
Banca: Jéssica Lemos Gulinelli
Banca: Martha Alayde Alcantara Salim
Resumo: Proposição: A proposta deste estudo foi avaliar por análise histométrica a resposta tecidual óssea de enxerto autógeno coletado por piezocirurgia para o preenchimento de defeitos nas porções cervicais de implantes instalados em tíbias de coelhos. Métodos: Foram instalados 26 implantes em 13 tíbias de coelho, após a estabilidade inicial foram realizados defeitos cervicais por trefinagem, em um grupo foi mantido apenas o coágulo como preenchimento e em outro grupo o defeito foi preenchido por osso autógeno coletado por equipamento piezoelétrico, os animais foram sacrificados após 15 e 30 dias, a análise histométrica das interfaces implante-osso foram realizadas pelo software Image Lab. Resultados: Foi analisado o percentual de extensão linear de contato entre tecido ósseo e implante, a média percentual obtida de contato entre tecido ósseo neoformado e implante foram estabelecidas como médias da área de osso neoformado entre as espiras e contato osso-implante (BIC). Os resultados obtidos foram: no controle de 15 dias, o percentual entre as espiras foi de 65,2% e entre as espiras e contato osso-implante (BIC) de 88,7%. No controle de 30 dias o contato entre as espiras foi na ordem de 65,2% e entre as espiras e contato osso-implante (BIC) de 73,2%. No grupo de enxerto de 15 dias, o osso formado entre as espiras foi de 69,3% e entre as espiras e contato osso-implante (BIC) em 81%, no grupo enxerto 30 dias o osso formado entre as espiras foi de 91,47% e entre as espiras e contato ossoimplante (BIC) 91,56%. Conclusão: o enxerto ósseo autógeno particulado obtido por piezocirurgia apresenta melhor resultado que o coágulo sanguíneo no osso neoformado entre as espiras e no contato osso-implante
Abstract: Purpose: The purpose of this study was to evaluate by histometric analysis the outcome of autogenous bone collected through piezo surgery equipment in filling cervical portion defects around implants placed in rabbits tibias. Materials and Methods: Twenty-six implants were installed in 13 rabbits tibias, after initial primary stability, cervical defects were carried out by the use of a trephina, in one group the cloth was maintained as the defect filling and in another group the defect was filled by autogenous bone collected through piezo surgery equipment, the animals were sacrificed after 15 and 30 days, the histometric analysis of the implant-bone interfaces were carried out by the use of Image Lab software. Results: The lineal stretch percentage of contact between bone and implant was analyzed, the average percentage obtained in the contact between the newly formed bone and the implant was established as the average area of the newly formed bone in the space between the spires and the bone-implant contact (BIC). The results obtained were: in the 15-days control group, the percentage of bone formation between the spires was of 65.2% and between the spires and boneimplant contact (BIC) was of 88.7%. In the 30-days control group the contact between the spires was of 65.2% and between the spires and bone-implant contact (BIC) of 73.2%. In the 15-days control grafted group, the formed bone between the spires was of 69.3% and between the spires and bone-implant contact (BIC) of 81%, in the 30-days control grafted group, the formed bone between the spires was of 91.47% and between the spires and bone-implant contact (BIC) of 91.56%. Conclusions: the autogenous bone collected through piezo surgery equipment showed better results than the blood clot regarding the newly formed bone between the spires and bone-implant contact (BIC)
Doutor

Introdução A abordagem do estudo dos recursos imaginológicos aplicados à análise óssea diz respeito ao estudo topográfico do periodonto e suas alterações. Consiste em avaliar a contribuição dos referidos recursos em razão das limitações dos exames convencionais. Objetivo Analisar por meio de dois sistemas de imagens digitais: a radiografia digital direta e a tomografia computadorizada por feixe cônico, comparando a eficácia de cada aparelho na análise das corticais do tecido periodontal e suas alterações. Métodos Cinco espécimes de mandíbulas foram incluídos em nosso estudo, com 6 tipos de defeitos ósseos distribuídos no septo interdentário e na porção radicular do dente. Radiografias periapicais foram realizadas, com o sensor sensor Dixi®2 (Planmeca Oy, Helsinki, Finlândia), e exames tomográficos, com o aparelho Newtom 3G (QR Srl, Verona, Itália). A pesquisa qualitativa, de caráter subjetivo, contemplou a análise das corticais ósseas avaliadas por três observadores em um total de 40 sítios para cada modalidade de exame. Teste estatístico de McNemar foi empregado para análise inter e intraobservadores. Resultados Resultados não concordantes foram relacionados à sobreposição de estruturas anatômicas em sua maior parte pela radiografia digital direta. Os resultados de acerto da tomografia computadorizada por feixe cônico: para análise da cortical vestibular do septo interdentário foi de 84%; para a cortical lingual de 92%; para a cortical proximal de 80%; e para cortical radicular de 80%, contra 60%, 64%, 80% e 46% respectivamente da radiografia digital. Não foram encontradas diferenças entre a 1ª e a 2ª análises na avaliação intra-observadores, contudo houve variação inter-observadores. Conclusões A tomografia computadorizada por feixe cônico mostrou-se como potencial recurso de imagem para análise das corticais ósseas do tecido periodontal. Entretanto, os resultados também apontaram que ambos os métodos são observador-dependentes, havendo necessidade de profissionais habilitados para utilização desses recursos recentes de imagem. Também avaliamos que estudos adicionais deveriam ser aplicados para maior entendimento do assunto estudado.
Introduction The study of the imaging resources applied to bone analysis regards to the topographic study of the periodontium and its changes. It is an assessment of the contribution of the related resources as compared to the limitations of conventional exams. Objective To analyze two digital imaging systems: the direct digital radiography and the cone beam computed tomography, comparing the efficacy of each device to analyze the cortical plates of the periodontal tissue and its changes. Methods Five mandible specimens were included in our study, with 6 types of bone defects distributed on the interdental septum and on the radicular portion of the tooth. Periapical radiographs with the Dixi®2 sensor (Planmeca Oy, Helsinki, Finland) and tomographic scans with Newtom 3G device (QR Srl, Verona, Italy) were obtained. The qualitative research, with a subjective feature, included the analysis of the bone cortical plates for a total of 40 sites with each examination method carried out by three observers. The McNemar statistic test was used for inter and intraobserver analyses. Results Results which did not agree were related to the overlay of anatomic structures mainly due to the direct digital radiography. The correct results for cone beam computed tomography were: 84% for the analysis of vestibular cortical plate of the interdental septum; 92% for lingual cortical plate; 80% for proximal cortical plate; and 80% for radicular cortical plate, against 60%, 64%, 80% e 46%, respectively, with digital radiography. No differences were found between the 1st and 2nd intraobserver analyses, but there was interobserver variation. Conclusion The cone beam computed tomography was shown to be a potential imaging resource for the analysis of the bone cortical plates of the periodontal tissue. However, the results also showed that both methods are observer-dependent, and there is a need for skilled professionals to use this recent imaging technology. In addition, we considered the additional studies that should be applied to improve the understanding of this subject.

碩士
長庚大學
顱顏口腔醫學研究所
92
Background: Regenerating a periodontal bony defect was more complicated. The reconstruction of both periodontal apparatus and adjacent bony defect was very important for dental health. Human recombinant bone morphogenetic protein 2 (rhBMP-2) in vivo studies have shown a significant potential for stimulating periodontal bone regeneration but limited regeneration of cementum and periodontal ligaments and with local root resorption or ankylosis. The retention period and dosage of BMP-2 at the healing wound seems to be an important factor. The application of regional gene therapy to delivery BMP-2 has been used to regenerate craniofacial bone successfully. Therefore, the purpose of this study was to evaluate the regeneration of periodontal apparatus in surgical created alveolar bony defects repaired with BMP-2 gene engineered autologous bone marrow mesenchymal stem cells (MSCs). Hypothesis: The regeneration of alveolar bony defects with BMP-2 gene engineered autologous bone marrow mesenchymal stem cells is the same as the nature regeneration of periodontal apparatus. Materials and Methods: Twenty four periodontal defects were surgically created bilaterally over the palate with central incisor roots denuded in 12 adult male New Zealand white rabbits. All defects were randomly assigned into four groups: BMP-2 gene infected MSCs/Pluronic F127 (advBMP-2 group), β-Gal gene infected MSCs/Pluronic F127 (advβ-Gal group), MSCs/Pluronic F127 (MSC group), and Pluronic F127 (PF127 group). The healing of bone, periodontal ligaments, cementum, and tooth surfaces were evaluated histologically. The total volume of bone regenerated was calculated from 3D CT and statistic analysis was performed. Results: Our data demonstrated the regeneration of periodontal apparatus was significantly better in advBMP-2 group. New cementum with Sharpey’s fiber was observed on the instrumented denuded palatal root surfaces in advBMP-2 group. Incomplete healing with localized resorption was noted in advβ-Gal, MSC, and PF127 groups. Larger amounts of bone were regenerated in advBMP-2 group compared to control groups. Conclusions: Ex vivo BMP-2 gene engineered autologous MSCs enhanced both bone and periodontal apparatus regeneration. Such a new approach to regenerate surgically created periodontal defects was a suitable application.

Introdução: Existem várias técnicas cirúrgicas para a preservação alveolar, entre as quais se destaca uma técnica desenvolvida por Tarnow, mais conhecida como “Ice Cream Cone”, utilizada em alvéolos tipo II, em que a cortical vestibular se apresenta parcialmente danificada depois da extração dentária. O objetivo deste estudo é determinar as alterações dimensionais ocorridas em alvéolos tipo II, reabilitados com implantes imediatos e com a técnica “Ice Cream Cone” para reconstrução da cortical vestibular nesta modalidade de tratamento. Materiais e Métodos O presente estudo foi de natureza observacional retrospetiva de implantes imediatos pósextração previamente colocados em alvéolos do setor anterior maxilar que apresentavam algum tipo de defeito ósseo associado à cortical óssea vestibular. Os pacientes foram submetidos a um scanner ótico intraoral, em momentos distintos de follow-up, entre os quais: T0 (antes da extração dentária); T1 (um mês após a colocação do implante); T2 (quatro meses após colocação do implante); e T3 (um ano após a colocação do implante). As imagens obtidas permitiram levar a cabo uma análise volumétrica e linear, de cariz digital, que avaliou as alterações dimensionais que ocorreram nos alvéolos tratados. Previamente á colocação do implante dentário, a realização de uma tomografia computorizada permitiu diagnosticar o defeito associado à cortical vestibular. Resultados Participaram neste estudo 7 pacientes com idade média de 53,00±17,66 (variação de 27 a 77 anos), tratados com 7 implantes imediatos unitários. Durante o período de seguimento, 6 pacientes foram observados após o primeiro mês de tratamento, 4 foram estudados aos 4 meses após a colocação do implante e 3 cumpriram o controlo pós-operatório estabelecido aos 12 meses após a cirurgia. Foi observada uma variação dos valores médios totais com perda volumétrica de 46,1±34,8 mm3 (T0-T1), 30,7±42,3 mm3 (T0-T2) e 70±0,65 mm3 (T0-T3). Relativamente às alterações dos tecidos peri-implantares lineares vestíbulopalatinos foram observados valores médios de perda de 0,94±0,65 mm (T0-T1), 0,6±0,62 mm (T0-T2) e 0,89 ±0,60mm (T0-T3). Quanto à variação da altura da mucosa peri-implantar obtivemos valores médios de perda a nível da papila mesial de 0,62±0,55mm, 0,64±0,53mm ao nível da papila distal e 0,72±0,62mm ao nível da margem gengival, após um ano de seguimento. Conclusão Os resultados clínicos obtidos demonstram que esta técnica a pode ser uma valiosa opção de tratamento mediante certas condições clínicas, biótipo gengival espesso e ausência de doença periodontal.
Introduction There are several surgical techniques for alveolar preservation, among which stands out the Tarnow technique, better known as "Ice Cream Cone", used in type II sockets, where the vestibular cortical is partially reduced after tooth extraction. The aim of this study is to determine the dimensional alterations that occurred in type II sockets, rehabilitated with immediate implants and with the "Ice Cream Cone" technique for buccal bone plate reconstruction. Materials and Methods The present study was a retrospective observational analysis of immediate post-extraction implants placed in the anterior maxillary sector, that presented some type of bone defect associated with vestibular cortical bone. The patients were submitted to an intraoral optical scanner (Cerec Omnicam®, Sirona Dental Systems GmbH, Bensheim, Germany), at different folow-up moments, which were: T0 (before tooth extraction); T1 (one month after implant placement); T2 (four months after implant placement); and T3 (one year after implant placement). The digital analysis protocol was performed as described in the literature and measurements of the linear and volumetric changes that occurred were conducted. A tomographic scan was conducted previously to the surgical procedure, so the dehiscence of the buccal cortical plate could be diagnosed. Results Seventy patients with a mean age of 53.00±17.66 (ranging from 27 to 77 years), treated with 7 immediate unit implants, participated in this study. During the follow-up period, 6 patients were observed after the first month of treatment, 4 were studied at 4 months after implant placement and 3 fulfilled the postoperative control established at 12 months after surgery. A variation of the total mean values with volumetric loss of 46.1 ±34.8mm3 (T0-T1), 30.7 ±42.3 mm3 (T0-T2) and 70±0.65 mm3 (T0-T3) were observed. Regarding changes in vestibule-palatine linear peri-implant tissues, mean loss values of 0.94±0.65 mm (T0-T1), 0.6 ±0.62 mm (T0-T2) and 0.89 ±0.60mm (T0-T3) were observed. The variation in the height of the peri-implant mucosa obtained mean loss values at the level of the mesial papilla of 0,62±0,55mm, 0,64±0,53mm at the level of the distal papilla and 0,72±0,62mm at the level of the gingival margin, during the first year of follow-up period. Conclusion The clinical results obtained demonstrate that this technique can be a valuable treatment option due to certain clinical conditions such has thick gingival biotype and absence of periodontal disease.

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

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.

碩士
台北醫學院
口腔復健醫學研究所
89
To assess the influence of various simulated types and degrees of alveolar bony defects on tooth mobility, 3-D finite element models of the human maxillary central incisor, canine and first molar were established. To simulate periodontal attachment loss, the bone elements of these models were deleted between 3mm to 10mm in 1mm decrement from cementum-enamel junction (CEJ). Resonance frequency values (RFV) of simulated one-side, two-side and three-side bony defects were calculated for comparison and discussion. The results showed that RFV of teeth was closely related to their surrounding bone level. When the horizontal bone loss was simulated, the RFV of the teeth demonstrated liner relationships with their attachment levels. On the other hand, when the vertical bony defect was simulated using these three tooth models, different effects of surrounding bone on the mobility of the teeth were observed. For the model of upper central incisor, the resonance frequency decreasing ratio (RFDR) with the bony defect at facial side, lingual side, mesial side and distal side were 8.2%, 14.1%, 12.7% and 11.7%, respectively. This means that the alveolar bone at the lingual side contributed more effect on the mobility of incisor than that of the facial side. However, the effect of alveolar bone of the mesial side was closely to the distal side. Different phenomena were observed in the model of canine, the RFDR with bony defects at facial side, lingual side, mesial side and distal side were 2.3%, 1.4%, 11.8% and 9.3%, respectively. This means that the alveolar bone at lingual side contributed similar effects on the mobility of incisor to that at facial side, and the effect of alveolar bone of mesial side was also similar to that at distal side. For the model of upper first molar, the RFDR with bony defects at buccal side, palatal side, mesial side and distal side were 5.5%, 2.3%, 17.2% and 23.1%, respectively. That is, the alveolar bone at buccal side contributed more effect on the mobility of molar than at palatal side. However, the effect of alveolar bone at mesial side demonstrated more effect on the mobility of molar than at distal side. Another noted finding is that the furcation of alveolar bone played a major role on the tooth mobility of first molar. These results suggested that vibration analysis method could be a useful, auxiliary clinical tool in the diagnosis of periodontal attachment loss.

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.

Introdução: A reabilitação protética de um espaço edêntulo delimitado garante o equilíbrio do sistema estomatognático: substitui as peças dentárias em falta, evita a extrusão dos dentes antagonistas, a movimentação dos dentes adjacentes e as alterações nas estruturas de suporte, como a reabsorção da crista óssea e a consequente modificação da arquitectura dos tecidos moles. O espaço edêntulo delimitado apresenta inúmeras variações, em dimensão, forma e localização. Deve ser cuidadosamente avaliado, para que a opção de tratamento definida alcance o sucesso clínico pretendido, com conforto e satisfação para o paciente, a nível estético e funcional. Objectivos: Elaboração e aplicação de uma Grelha de Avaliação Clínica em espaços edêntulos delimitados de pacientes da Clínica Universitária da UCP-CRB, na área da Prostodontia Fixa. Materiais e Métodos: Análise das publicações relacionadas com as características presentes em espaços edêntulos delimitados, com recurso à MEDLINE - Pubmed e Scirus como bases de dados. Descrição de todas as consequências observáveis e reunião das mesmas numa Grelha de Avaliação Clínica, que permita uma aquisição simples e sistematizada do diagnóstico, plano de tratamento e prognóstico da reabilitação protética fixa. Aplicação clínica da grelha elaborada. Resultados e Conclusão: A reabilitação de espaços edêntulos delimitados exige, frequentemente, adaptações pré-protéticas, quer ao nível da extensão mesio-distal do pôntico, quer ao nível da crista residual. Uma abordagem multidisciplinar do paciente e do espaço a ser reabilitado é vantajosa. Com base na Grelha de Avaliação Clínica elaborada e aplicada, o Paciente 1 apresenta um espaço edêntulo delimitado avaliado em Classe 1 e o Paciente 2 em Classe 2. Ambos são minorados para Classe 0 por se tratar de situações não visíveis. O Paciente 3 apresenta um espaço edêntulo delimitado totalmente íntegro, visível em sorriso (Classe 1). Desta forma, foi possível definir um plano de tratamento e prognóstico relativamente à reabilitação dos pacientes avaliados.
Introduction: The prosthetic rehabilitation of bounded edentulous spaces ensures the balance of the stomatognathic system: replaces missing teeth, avoids opposing teeth extrusion, adjacent teeth tipping and supporting structures changes, like alveolar bone resorption and consequent alteration in soft tissue architecture. The bounded edentulous space has several variations in size, shape and location. It should be carefully assessed so that the treatment option can achieve clinical success, with comfort and satisfaction to patient at functional and esthetic level. Objectives: Elaboration and application of a Clinical Assessment Grid in bounded edentulous spaces of UCP-CRB University Clinical patients, in fixed prosthodontics. Materials and Methods: Review of publications related to the features of bounded edentulous spaces, using the MEDLINE – Pubmed and Scirus as databases. Description of all observable consequences of these and its reunion in a Clinical Assessment Grid to allow simple and standardize diagnosis, treatment plan and prognosis of fixed prosthetic rehabilitation. Clinical application of the produced grid. Results and Conclusion: The rehabilitation of bounded edentulous space often requires pre- prosthetic adjustments, at mesio-distal extent or at the residual ridge. A multidisciplinary approach of the patient and the space to be restored has advantages. Based on Clinical Assessment Grid developed and implemented, Patient 1 has a bounded edentulous space in Class 1 and Patient 2 in Class 2. Both are decreased to Class 0 for being not visible. Patient 3 has a totally intact bounded edentulous space, visible in smile (Class 1). Thus, it was possible to achieve a treatment plan and prognosis of the evaluated patients.