Tesi sul tema "Endodontic"

Thesis (M.S.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains vii, 32 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 29-31).

Orientador: Brenda Paula Figueiredo de Almeida Gomes
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
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Resumo: Os objetivos deste estudo foram analisar a microbiota de canais radiculares com necrose e com lesão periapical de dentes sintomáticos e assintomáticos; quantificar a presença de endotoxinas; correlacionar a presença de bactérias específicas e a quantidade de endotoxinas com os sinais e sintomas de origem endodôntica; e investigar a suscetibilidade antimicrobiana de bactérias anaeróbias estritas isoladas dos canais radiculares contra 8 antibióticos, usando o E-test. Amostras microbiológicas foram coletadas de 90 canais radiculares com polpa necrosada e processadas por meio de técnicas microbiológicas. Outras 50 amostras foram obtidas de canais radiculares necrosados, sintomáticos e assintomáticos para realização do teste cromogênico para quantificação das endotoxinas. Análise estatística foi feita pelos testes x2 de Person ou de Fisher. Um total de 400 isolados clínicos foi encontrado, os quais pertenciam a 69 diferentes espécies e 22 diferentes gêneros. Oitenta por cento das bactérias eram anaeróbias estritas e F. nucleatum foi a espécie predominante. Canais radiculares de dentes sintomáticos apresentaram uma predominância de anaeróbios estritos e um número maior de espécies por canal radicular em relação aos dentes assintomáticos. Foi observada uma relação entre grupos microbianos específicos, principalmente anaeróbios Gram-negativos e a presença de dor espontânea ou dor prévia, dor à percussão, dor à palpação e edema. Endotoxinas foram encontradas em altas concentrações em canais radiculares de dentes sintomáticos e houve uma correlação positiva entre os sinais e sintomas e a concentração de endotoxinas. Amoxicilina, amoxicilina associada ao ácido clavulânico e cefaclor foram efetivos contra todas as cepas testadas. Os resultados sugerem que bactérias específicas e endotoxinas estão associadas aos sinais e sintomas de dentes com canais infectados e lesão periapical e que, a maioria das espécies anaeróbias testadas foi suscetível aos antibióticos estudados
Abstract: The aim of this study was to analyse the microflora isolated from infected root canals of symptomatic or asymptomatic teeth, to quantify the presence of endotoxins; to correlate the presence of specific bacteria and the amount of endotoxins with endodontic symptomatology; and to investigate the antibiotic susceptibility of anaerobic bacteria isolated from infected teeth with periapical lesions against 8 antibiotics through the E-test. Microbial samples were taken from 90 root canals of teeth with necrotic dental pulp, and analysed using rigorous culture procedures. Other 50 samples were collected from infected symptomatic or asymptomatic root canals in order to be analysed by a chromogenic test for the endotoxin quantification. Statistical analysis used a Pearson x2 test or a one-sided Fisher's Exact test, as appropriate. A total of 400 cultivable isolates were recovered from 69 different microbial species and 22 different genera. Eight per cent of the bacteria were were strict anaerobes and F. nucleatum was the most frequently isolated species. Root canals from symptomatic teeth harboured more obligate anaerobes and a larger number of bacterial species than the asymptomatic teeth. Relationships were found between specific microorganisms, especially Gram-negative anaerobes and the presence of pain or history of pain, tenderness to percussion, pain to palpation and swelling. High concentrations of endotoxins were found in root canals of symptomatic teeth and there was a positive correlation between endodontic signs and symptoms and the concentration of endotoxins in infected root canals. Amoxicillin, amoxicillin + clavulanate and cephaclor were effective against all the strains tested. Our results suggested that specific bacteria and endotoxins are associated with endodontic symptoms of infected teeth and that the majority of the anaerobic species tested was susceptible to all antibiotics studied.
Doutorado
Endodontia
Doutor em Clínica Odontológica

O intuito do presente trabalho foi avaliar in vitro a desinfecção de canais radiculares de pré-molares inferiores humanos, variando a técnica de preparo e os regimes de irrigação utilizados. Para isso, 85 espécimes foram padronizados em comprimento e diâmetro apical e, após o devido preparo, receberam contaminação com Enterococcus faecalis e Candida albicans por 28 dias. Os canais foram divididos em 8 grupos: G1 - instrumentação manual associada à irrigação com solução fisiológica; G2 - instrumentação manual associada à irrigação com NaOCl à 1,0%; G3 - instrumentação manual associada à irrigação com NaOCl à 1,0% e AC à 15%; G4 - instrumentação manual associada à irrigação com NaOCl à 5,25%; G5 - instrumentação rotatória associada à irrigação com solução fisiológica; G6 - instrumentação rotatória associada à irrigação com NaOCl à 1,0%; G7 - instrumentação rotatória associada à irrigação com NaOCl à 1,0% e AC à 15%; G8 - instrumentação rotatória associada à irrigação com NaOCl à 5,25%. O grupo controle negativo foi composto por 5 dentes preenchidos com meio de cultura esterilizado. Todos os canais dos grupos experimentais foram preparados até instrumentos com diâmetro final de 0,50mm. Coletas microbianas foram realizada antes e após o PQC, com auxílio de pontas de papel esterilizadas. Raspas de dentina foram coletadas após o PQC com o intuito de verificar a ocorrência de MOs no interior dos túbulos dentinários. Não houve diferença estatística entre as técnicas de instrumentação, quanto à diminuição microbiana no interior dos canais. Quanto aos regimes de irrigação, o soro fisiológico produziu os piores resultados, seguido pelo NaOCl à 1,0%. Já quando acompanhado pelo AC, a desinfecção alcançada não demonstrou diferença estatística quanto aos grupos irrigados com NaOCl à 5,25%.
The purpose of this study was to evaluate the in vitro disinfection achieved in root canals of human mandibular premolars, varying the preparation technique and irrigation regimens. For this, 85 specimens were standardized in length and apical diameter, and after proper preparation were contaminated with Enterococcus faecalis and Candida albicans for 28 days. After this period, the canals were divided into eight experimental groups as follows: G1 - hand instrumentation with irrigation with sterile saline, G2 - hand instrumentation with irrigation with NaOCl to 1.0%, G3 - Manual instrumentation with irrigation with NaOCl to 1.0% and citric acid to 15%, G4 - instrumentation associated with irrigation with NaOCl at 5.25%; G5 - rotary instrumentation associated with irrigation with sterile saline and G6 - rotary instrumentation associated with irrigation with NaOCl to 1.0%; G7 - rotary instrumentation with irrigation with NaOCl to 1.0% and citric acid to 15%; G8 - rotary instrumentation with irrigation with NaOCl at 5.25%. Negative control group was composed of 5 teeth had their canals filled with sterile culture medium. All root canals of the specimens of experimental groups were prepared by instruments with a diameter equivalent to the tip end of 0.50 mm. Microbial samplings were performed before and after the PQC with the aid of sterilized paper points. Dentine chips were collected after the PQC in order to verify the occurrence of microorganisms inside the dentinal tubules. The results showed no statistical difference between the techniques of instrumentation, on the microbial reduction. As for systems of irrigation, saline produced the worst results followed by NaOCl 1.0%. When followed by citric acid, disinfection achieved no difference for the groups irrigated with NaOCl at 5.25%

Endodontic residents must keep current with clinical information to practice evidence- based dentistry. To do so, endodontic residents must access research papers and interpret results. This requires a knowledge of biostatistics. However, the biostatistical knowledge of endodontic residents is relatively unknown. The purpose of the study was to assess the biostatistical knowledge of endodontic residents using a survey instrument to prove or reject the hypothesis that there exists a lack of understanding of biostatistic principles among endodontic residents. A survey consisting of 29 questions querying attitudes and biostatistical knowledge was distributed to 230 endodontic residents and returned with a 32% response rate. The overall mean resident knowledge score was 42.3% (SD, 17.5%; range, 10% to 90%). Only 39% stated they understood all of the statistical terms encountered in journal articles. This data supports the hypothesis that there exists a lack of understanding of biostatistical principles and would suggest that more effective training in biostatistics in residency education is desirable.

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
Introdução: O presente trabalho desenvolve o seguinte tema: Retratamento Endodôntico Cirúrgico, que surgiu como uma subdivisão da Endodontia. O Retratamento Endodôntico Cirúrgico tem os mesmos princípios de desinfecção, conformação e obturação que o tratamento convencional, no entanto é mais invasivo. Está indicado em casos de insucesso prévio no tratamento endodôntico não cirúrgico, em perfurações acidentais, presença de lesões radiolucentes, fractura de instrumentos e na presença de prótese (estética). Objectivos: Esta dissertação tem como objectivo principal explorar um ramo da Endodontia: a Endodontia Cirúrgica. Procedeu-se a uma revisão bibliográfica, analisando a literatura que versa o tema, de modo a investigar o Retratamento Endodôntico Cirúrgico, nas suas diferentes dimensões: a evolução da técnica, o protocolo cirúrgico em toda a sua extensão, a sua utilidade e aplicabilidade na prática clínica e a sua taxa de sucesso. Materiais e Métodos: Para a execução desta revisão bibliográfica, entre Abril e Outubro de 2015, recorreu-se a motores de pesquisa on-line: b-On, Pubmed, Scielo, Science Direct, ResearchGate e Google Académico, concretizando a investigação através das palavras-chave: “endodontic microsurgery”, “apicectotmy”, “retrofilling techniques”, “endodontics microsurgery highlights” e “surgical endodontic treament”. Foram consultados 88 artigos e 8 livros. Discussão/Resultados: Na literatura científica, quando o Retratamento Endodôntico Cirúrgico é comparado com o tratamento não cirúrgico, relativamente ao sucesso final do tratamento, não parece haver uma grande diferença. Mas quando, dentro deste tratamento, a técnica tradicional é comparada com a técnica microcirúrgica, esta última sendo um produto final do progresso da técnica tradicional, apresenta uma evolução gigantesca e taxas de sucesso inigualáveis. Segundo estudos documentados, comparativamente aos materiais retrobturadores existentes, o MTA parece ser o melhor material selador, no entanto existem estudos no sentido de se adquirir um material com o selamento ideal. Os resultados apresentados na literatura demonstram uma boa taxa de sucesso para esta técnica. Mas, maioritariamente, os autores referem que esta deverá ser usada como um dos componentes do retratamento e não isoladamente. Conclusões: No trabalho realizado, conclui-se que a Endodontia Cirúrgica teve um grande desenvolvimento nestes últimos anos, nomeadamente: a nível da técnica, instrumentos, materiais retrobturadores e da utilização do microscópio (iluminação e ampliação). Estes progressos tornaram-na uma opção de tratamento fiável e previsível, mas que requer muita experiência por parte do operador. Actualmente, esta técnica é uma opção terapêutica, quando o tratamento convencional não é possível, contudo apresenta algumas limitações e desvantagens, nomeadamente o facto ser algo invasiva para o paciente.
Introduction: This paper develops the following theme: Surgical Endodontic Retreatment, which has emerged as an Endodontics subdivision. Surgical Endodontic Retreatment has the same principles of disinfection, conforming and filling than conventional non-surgical treatment, however it is more invasive. It's indicated in cases of previous failure in non-surgical endodontic treatment, in accidental perforations, the presence of radiolucent injury, fracture of instruments and in the presence of prosthesis (aesthetics). Objectives: This thesis main goal is to explore a branch of Endodontics: Surgical Endodontics. A literature review has been done, analyzing the existent literature in order to investigate the Surgical Endodontic Retreatment, in its different dimensions: the technique’s evolution, the surgical protocol in its entire length, its use and applicability in clinical practice and its success rate. Materials and Methods: In the carrying out of this literature review, it was used the online search engines, between April to October of the present year, such as: b-On, Pubmed, Scielo, Science Direct, ResearchGate and Google Scholar, implementing research through the keywords: "endodontic microsurgery", "apicectotmy", "retrofilling techniques", "endodontics microsurgery highlights", and "surgical endodontic treament". In total, 88 articles and 8 books were consulted. Discussion/Results: In scientific literature, when Endodontic Surgery Retreatment is compared with non-surgical treatment regarding the ultimate success of the treatment, doesn't seem to have a big difference. But when, within this treatment, the traditional technique is compared to the microsurgical technique, this last one being a final product from the traditional technical progress, presenting an enormous evolution and unparalleled success rates. According to documented studies, compared to existing retrofilling materials, MTA seems to be the best sealing material, however there are studies in order to acquire an ideal sealing material. The results reported in the literature show good success rate for this technique. But, mostly, the authors report that this should be used as a component of retreatment and not as a single treatment. Conclusion: In this thesis it has been concluded that Surgical Endodontics had a great development in these past years, in terms of: technique level, instruments, root-end filling materials and the use of the microscope (illumination and magnification). These developments have made it a reliable and predictable treatment option, but it requires a lot of experience by the operator. Currently, this technique is a therapeutic option when conventional treatment is not possible, nonetheless, it presents a few limitations and disadvantages, including the fact of being somewhat invasive for the patient.

"A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science. Endodontics, College of Dental Medicine, Nova Southeastern University, July, 2006."

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Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG
Objectives: To determine the antibacterial effect provided by Endox system associated with different irrigation protocols in the preparation of infected root canals. Material and methods: A total of 18 extracted human teeth with anatomical diameters corresponding to approximately 350-400 micrometers were selected. The teeth were contaminated with suspension of Enterococcus faecalis (ATCC 29212) for 60 days and randomly divided into five groups: 1. root canal preparation (RCP) + passive ultrasonic irrigation (PUI) with NaOCl + EDTA; 2. RCP + PUI with NaOCl + EDTA + Endox system; 3. RCP + conventional irrigation (CI) with NaOCl + EDTA 4. RCP + CI with NaOCl + EDTA + Endox system; 5. RCP + PUI with distilled water + EDTA + Endox system. Three teeth uncontaminated were the negative control (group 6). Samples were taken from the root canals before the RCP after 20 minutes and 72 hours, immersed in 7 ml of Brain Heart Infusion (BHI) for a period of 48 hours, incubated at 37 °C. The presence of bacterial was assessed by turbidity of the culture medium followed by optical density analysis using UV spectrophotometer. The differences between groups were statistically analyzed by mean, standard deviation, variance analysis and Tukey test (post hoc). The significance level was 5%. Results: The presence of E. faecalis was observed after 72 h in all experimental groups. In Groups 2 and 4 decreased the optical density of the culture medium after 72 h, with no significant difference between them, while in Groups 1, 3 and 5 was increased. The average optical density of the culture medium was zero in Group 6. Conclusion: The Endox system used after the root canal preparation, associated with conventional irrigation or passive ultrasonic irrigation with NaOCl 2,5% / EDTA, was not effective in eliminating E. faecalis.
Objetivo: Avaliar o efeito antibacteriano proporcionado pelo sistema Endox associado a diferentes protocolos de irrigação durante o preparo de canais radiculares (PCR) infectados. Material e método: Foram selecionados 18 dentes humanos anteriores extraídos com diâmetros anatômicos correspondentes a aproximadamente 350-400 micrômetros. Os dentes foram contaminados com suspensão de Enterococcus faecalis (ATCC 29212) por 60 dias, e aleatoriamente distribuídos em cinco grupos experimentais: Grupo 1. PCR + irrigação ultrassônica passiva (IUP) com NaOCl 2,5% + EDTA; Grupo 2. PCR + IUP com NaOCL 2,5% + EDTA + sistema Endox; Grupo 3. PCR + irrigação convencional (IC) com NaOCl 2,5% + EDTA Grupo 4. PCR + IC com NaOCl 2,5% + EDTA + sistema Endox; Grupo 5. PCR + IUP com água destilada + EDTA + sistema Endox. Três dentes não contaminados constituíram o grupo controle negativo (Grupo 6). Amostras foram coletadas dos canais radiculares antes do PCR, após 20 minutos e 72 horas, imersas em 7 mL de Brain Heart Infusion (BHI) por um período de 48 horas, incubadas a 37ºC. A presença bacteriana foi analisado pela turvação do meio de cultura seguido pela mensuração da densidade óptica utilizando espectrofotômetro UV. As diferenças entre os grupos foram analisadas estatisticamente pela média, desvio padrão, análise de variância e teste de Tukey (post hoc). O nível de significância foi de 5%. Resultados: A presença de E. faecalis foi observada, após 72 h, em todos os grupos experimentais. Nos Grupos 2 e 4 houve redução da densidade óptica do meio de cultura após 72 h, não havendo diferença significativa entre ambos, enquanto que nos Grupos 1, 3 e 5 houve aumento. A média da densidade óptica do meio de cultura no Grupo 6 foi zero. Conclusão: O sistema Endox, utilizado após o preparo do canal radicular, associado a irrigação convencional ou irrigação ultrassônica passiva, com NaOCl a 2,5%/ EDTA, não foi efetivo na eliminação do E. faecalis.

Atualmente, sabe-se que determinar a vitalidade pulpar testando apenas a sua resposta sensorial nervosa, através de testes térmicos ou elétricos, é discutível, pois tais procedimentos não são suficientemente sensíveis para determinar, em definitivo, o real grau de envolvimento pulpar. Além disso, a vitalidade da polpa não depende apenas de seu suprimento nervoso, mas de seu suprimento sanguíneo. Outro fator a considerar com relação ao diagnóstico pulpar, deve-se à possibilidade da ocorrência de respostas pouco confiáveis em pacientes excessivamente ansiosos ao tratamento odontológico, independente do estímulo empregado e da intensidade do teste. O diagnóstico da vitalidade pulpar através de meios de mensuração da temperatura da coroa do dente, como a termografia infravermelha, que avalia a distribuição de temperatura num corpo através da radiação emitida pela sua superfície, surge como possibilidade para superar as desvantagens dos testes de sensibilidade, como a necessidade da estimulação, as variáveis decorrentes da espessura de dentinaesmalte dos dentes, a idade dos pacientes, a condição da estrutura dentária, entre outras. Esta pesquisa verificou a aplicabilidade da imagem infravermelha na análise da queda de temperatura produzida pelo teste térmico com gás refrigerante e a viabilidade como recurso semiotécnico para diagnóstico endodôntico. Para tal, foram analisados quatro dentes portadores de polpa vital e dois dentes tratados endodonticamente. A metodologia utilizada avaliou, através da imagem térmica, a temperatura da superfície coronária submetidos à queda de temperatura, com e sem a utilização do isolamento absoluto. Os resultados não mostraram diferença significante entre os dentes estudados, no que diz respeito à temperatura da superfície coronária e que a utilização do isolamento absoluto também não alterou os resultados. A metodologia proposta neste estudo mostrou-se altamente eficaz para a análise de mudanças térmicas na superfície dentária. No entanto, novos estudos devem ser realizados para que a termografia infravermelha possa se tornar um recurso viável para utilização em Endodontia.
Nowadays, it is known that the determination of the pulp vitality testing only its nerve sensorial response through thermal or electrical tests is discussable because those procedures are not sufficiently sensitive to determine the degree of pulp involvement. Besides the vitality of the pulp does not only depend on its nerve condition, but on its blood supply too. Another factor to consider during the pulp diagnostic, independently of the nature of stimulus or their intensity, is the possibility to occur non reliable responses in excessively anxious patients face to the dentistry treatment. The diagnosis of the pulp vitality by the measurement of the dental crown temperature such as the infrared thermography (which evaluates the temperature distribution in a body through the radiation emitted by its surface) arises as a possibility to overcome the sensitivity tests disadvantages, for example: the stimulation necessity, the variants due to the thickness of the dentin and enamel, the age, the condition of the dental structure and etc. This study evaluated the applicability of the infrared thermography test in the analysis of temperatures decline produced by thermal test using cold spray, and its viability as an aid for the endodontic diagnostic. Using thermal imaging, this methodology analyzed the temperature of the crowns surface of four teeth with vitality and two endodontically treated teeth when submitted to the cold test with and without the use of rubber dam. The results did not show a significant difference between teeth conditions with regard to the crowns surface temperature and the use of rubber dam did not affect these results. The proposed methodology used in this study showed to be highly efficient to analyzing the thermal changes on the dental surface; however new studies must be performed to turn infrared thermography a practicable aid into the endodontic practice.

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
A evolução constante da Endodontia tem proporcionado novas formas e melhores resultados no tratamento de canais radiculares infectados. Sabemos que o sucesso endodôntico está dependente da limpeza e remoção dos microorganismos, devolvendo ao sistema de canais radiculares (SCR) condições ideais de assepsia, restabelecendo a função do dente. Assim, o sucesso endodôntico está dependente de uma correta conformação, desinfeção e selamento do SCR. A desinfeção do SCR inclui procedimentos de limpeza mecânica e química, existindo atualmente várias técnicas de instrumentação, esquemas de irrigação e medicação intracanalar. Apesar da complexidade do SCR, os irrigantes desempenham um papel fundamental no sucesso da TENC. De entre todas as soluções irrigantes conhecidas, a que mais se aproxima da solução irrigante ideal é o NaOCl devido às suas propriedades demonstradas por vários estudos. A eficácia do NaOCl pode ser influenciada por diversos factores como a sua concentração e pH, a temperatura, o tempo de exposição e pelo seu modo de agitação. Além de ser utilizado isoladamente, o NaOCl pode ser associado a outras soluções irrigantes como o gluconato de clorexidina ou com o EDTA, trazendo inúmeras vantagens para um desbridamento mais eficaz do SCR. Para tal a pesquisa bibliográfica foi realizada nos motores de busca: PubMed e Science Direct, utilizando as palavras-chave “endodontic irrigation”, “endodontic irrigants” e “sodium hypochlorite”. Foram incluídos artigos em português e inglês, publicados entre 1988 e 2015. A pesquisa foi realizada entre Fevereiro de 2015 e Junho de 2015. Em suma, a utilização das diversas soluções irrigantes e a sua associação traz efeitos vantajosos para o sucesso da TENC.
The constant evolution of Edodontic has given us new ways of treatment and with those, better results in the processing of infected root canals. It is known that edodontic success is related with the removal and cleaning of microorganisms, providing perfect asepsis conditions to the system root canals (SCR) and in accordance with that re-establish tooth functions. Therefore, endodontic success depends on a correct conformation, disinfection and sealing of the SCR. SCR disinfection has different mechanical and chemical cleaning procedures, currently we have several such as irrigation schemes, instrumentation techniques or intracanalar medication. Despite of all SCR complexity, irrigators have a key role in TENC's success. Among all known irrigating solutions, several studies have proved that NaOC1 can give the best irrigating solution due to its properties. NaOC1 efficiency may be affected by many factors, for example pH concentration, temperature, exposure time and agitation mode. Besides NaOC1 could be used alone, it can also be associated to other solutions: chlorhexidine gluconate or EDTA. These associations permit us to have a considerable number of advantages for a more effective SCR debridement. A bibliographic research was made on: PubMed and Science Direct, searching for “endodontic irrigation”, “endodontic irrigants” and “sodium hypochlorite” as key words. It has been included Portuguese and English articles, published between 1988 and 2015. The research was conducted between February 2015 and June 2015. Resuming, the use of different irrigating solutions and its associations lead to a beneficial effect on the success of TENC.

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
A restauração de dentes tratados endodonticamente é um dos temas mais estudados e controversos em Medicina Dentária. As opiniões são contraditórias em relação aos procedimentos clínicos e materiais a serem utilizados para restaurar estes dentes. Para planear e executar um tratamento restaurador de dentes tratados endodonticamente corretamente, é importante o Médico Dentista estar ciente das alterações destes dentes e prever possíveis intercorrências, planeando a abordagem mais correta para cada caso. O tratamento endodôntico, possibilita o restabelecimento funcional e estético de dentes acometidos por inúmeras alterações patológicas com envolvimento pulpar/periapical e aumenta, consideravelmente, a viabilidade da manutenção do dente na arcada dentária. No entanto, a recuperação definitiva do dente só ocorre no final do tratamento endodôntico com o tratamento restaurador. A decisão quanto ao tipo de restauração ideal e/ou a retenção intra-radicular a ser utilizado é complexa e difícil, envolve muitos factores e varia significativamente de acordo com o caso clínico. Cada caso clínico requer uma avaliação e um desenho individual. The restoration of endodontically treated teeth is one of the most studied and controversial topics in dentistry. The opinions are contradictory in relation to clinical procedures and materials to be used to restore these teeth. To plan and implement a restorative treatment of teeth endodontically treated properly, it is important to be aware of these changes and predict possible events, planning the most correct approach for each case. Root canal therapy, enables the functional and esthetic restoration of teeth affected by numerous pathological changes with pulp / periapical and greatly increases the viability of maintaining the tooth in the dental arch involvement. However, the final recovery of the tooth occurs only at the end of TENC with the restorative treatment. The decision regarding the type of ideal restoration and / or intra-radicular retention to be used is complex and difficult, involving many factors and varies significantly according to the clinical case. Each case requires a clinical assessment and an individual design.

Aim: The aim of the current study was to develop two formulations loading calcium hydroxide (Ca(OH)₂) and Clobetasol Propionate into poly lactic-co-glycolic acid (PLGA) biodegradable nanoparticles (NPs) to be used in the field of endodontics as an intracanal medications, including NPs optimization and characterization, plus drug release profile of the NPs compared to free drug counterpart. Additionally, comparison of the depth and area of penetration of the NPs inside the dentinal tubules against the free drug was carried out. Furthermore, the therapeutic efficacy for both formulations were examined using antibacterial and anti-inflammatory assays. Methodology: NPs were prepared using the solvent displacement method. Optimization of the NPs was carried out with a central composite design to obtain a final optimized formulation. The NPs morphology was examined under transmission electron microscopy (TEM), plus characterization was done by x-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Moreover, the optimal conditions and cryoprotectants for freeze drying of the NPs were examined and tested. The drug release profile of the NPs and free drug was evaluated up to 48 hours. Additionally, the depth and area of penetration inside the dentinal tubules was examined for both the NPs and free drug. Antibacterial testing was performed on the antibacterial NPs to evaluate their efficacy in eliminating different bacterial strains. Agar disk-diffusion and broth dilution were used to determine the inhibition growth zones and the minimal inhibitory concentration (MIC). Likewise, anti-inflammatory testing was performed on the Clobetasol Propionate anti-inflammatory NPs, in which their response and reaction against inflammatory cells, in particular against macrophages was tested using the enzyme-linked immunosorbent assay (ELISA) to examine the cytokine release of IL-1β and TNF-α. Results: Using the solvent displacement method, both formulations of NPs were successfully optimized. The characteristics of the NPs utilizing the optimized formula showed a polidpsersity index (PI) value lower than 0.2, characteristic of monodisperse systems and an average size below 200 nm along with a highly negative surface charge (measured as zeta potential, ZP) and maximum entrapment efficiency (EE) percentage. For both the Ca(OH)₂/PLGA and the clobetasol propionate/PLGA NPs, the characterization of the NPs was performed, and the spherical morphology was confirmed using TEM. Moreover, interaction studies were carried out including XRD, FTIR and DSC to examine the profile of the NPs. These studies confirmed that no covalent bonds were formed during the preparation process and that the drug appeared to be encapsulated inside the NPs. Examining the drug release profile for the Ca(OH)₂/PLGA NPs, the Ca(OH)₂ NPs exhibited a prolonged and steady release with higher concentrations than those obtained with the free Ca(OH)₂, that remained stable up to 48 hours. Moreover, clobetasol propionate/PLGA NPs, exhibited a prolonged and steady release with only around 21 % of the encapsuled drug released after 48 hours, in comparison the free drug that was completely released after just 6 hours. For the freeze drying of the Ca(OH)₂/PLGA NPs, the combination of 5% of (2-Hydroxypropyl)-β-cyclodextrin and 15% D-mannitol gave rise to the most stable outcome and the best appearance after lyophilization being able to recover the initial physicochemical characteristics of the NPs after their resuspension. Unfortunately, for the clobetasol propionate/PLGA NPs, we were not able to achieve a suitable combination. Using the confocal laser scanning microscopy, it was shown that both the Ca(OH)₂/PLGA and the clobetasol propionate/PLGA NPs had a better depth and area of penetration inside the dentinal tubules when compared to the free drug. Plus, the NPs displayed higher values mean fluorescence intensity (MFI) and integrated density compared to the free drug. Assessing the antibacterial efficiency of the Ca(OH)₂/PLGA NPs using the agar diffusion test, it was noted that the NPs showed clear maximal zones of growth inhibition around the filter papers comparable only to the positive group of antibiotics. Additionally, the MIC of the NPs was measured in regard to inhibiting bacterial growth for 3 bacterial species. It was noted that after 24 hours of incubation the NPs were able to inhibit bacterial growth at all tested concentrations. The anti-inflammatory capacity of the clobetasol propionate/PLGA NPs was also examined, in which ELISA assays were used to evaluate the inflammatory cytokines release of the macrophages in response to the NPs. The releases of TNF-α was reduced considerably to almost undetectable amounts with NPs compared to the LPS negative control, displaying results similar and even less than the TCP positive control after 48 hours. However, resulted in the release of IL-1β in higher amounts which were similar to the TCP positive control and lesser than the LPS negative control group. Additionally, the inflammatory cytokines release of IL-1β and TNF-α from the LPS pretreated macrophages, was not reduced with the NPs at all tested concertation to limits below the amounts obtained by the LPS pretreated macrophages or the TCP positive control group after 48 hours. Conclusions: In the present study, Ca(OH)₂ loaded PLGA NPs and clobetasol propionate loaded PLGA NPs were successfully optimized and characterized, and their therapeutic efficacy was tested with aims to increase the antibacterial and anti-inflammatory effect through controlled drug release and reach areas of complicated root canal anatomy due to the smaller mean nanoscopic size. However, further future studies are still required in order for the developed NPs to take the next step to be utilized in a clinical condition and to achieve its goal as an intracanal medicament.
Objetivo: El objetivo del presente estudio ha sido el desarrollo de dos formulaciones encapsulando hidróxido de calcio (Ca(OH)₂) y clobetasol en nanopratículas (NPs) biodegradables de ácido poli(láctico-co-glicólico) (PLGA) para ser usadas en el campo de la endodoncia como medicación intra-conducto, incluyendo la optimización y caracterización de las NPs y el perfil de liberación del principio activo en comparación con el fármaco libre. Adicionalmente se comparó la cantidad y el área de penetración de las NPs en el interior de los túbulos dentinarios. Las eficacias terapéuticas de ambas formulaciones fueron examinadas mediante test antibacterianos y antiinflamatorios. Metodología: Las NPs fueron preparadas por el método de desplazamiento de solvente. La optimización fue realizada mediante un diseño factorial central compuesto obtenido la formulación final. Se realizó un estudio de la morfología de las NP mediante microscopía electrónica de transmisión (MET). Además, las NPs se caracterizaron mediante cristalografía de Rayos X, espectroscopía infrarroja de Fourier y calorimetría diferencial de barrido. También se examinaron y llevaron a cabo el estudio de las condiciones óptimas para el proceso de liofilización de las NP. Se evaluó el perfil de liberación del fármaco desde el interior de las NP comparándolo con el del fármaco libre, hasta las 48 horas. El examen de penetración dentro de los túbulos dentinarios de las NP en comparación con el fármaco libre se realizó mediante microscopía confocal. Para evaluar la capacidad antibacteriana de las NP de hidróxido de calcio se realizaron los test de método Kirby-Bauer (Test de difusión en agar) y la concentración mínima inhibitoria (CMI). En las NP de propinado de clobetasol se evaluó su respuesta y reacción frente a células inflamatorias, en particular frente a macrófagos, utilizando el ensayo inmunoabsorbente ligado a enzimas (ELISA) para examinar la liberación de citocinas de IL -1β y TNF-α. Resultados: Las formulaciones de NPs con hidrócido de calcio y clobetasol se prepararon utilizando el método de desplazamiento de solvente. Las características de las formulaciones optimizadas presentaron una población homogénea con un valor de índice de polidispersión (PI inferior a 0,2) y tamaño promedio adecuado, inferior a 200 nm. Además, su carga superficial medida en base al potencial zeta fue altamente negativa y se obtuvo una eficiencia de asociación elevada en ambos casos, superior para el clobetasol. Tanto para las NP de Ca (OH) ₂ / PLGA como para las NP de propionato de clobetasol / PLGA, se confirmó su morfología esférica y su superficie lisa mediante MET. Se realizaron diferentes estudios de interacción fisicoquímica confirmando que ambos fármacos se encontraban en el interior de la matriz polimérica y que no se producían nuevos enlaces en la formación de los sistemas nanoestructurados. Se examinó el perfil de liberación para ambas formulaciones. En el caso de las NP de Ca (OH) ₂ / PLGA, las NP de Ca (OH) ₂ mostraron una liberación prolongada y constante del fármaco con concentraciones más altas que en el caso dl fármaco libre, que permanecieron estables hasta 48 horas después. Las NP de propionato de clobetasol / PLGA exhibieron una liberación prolongada y constante con una liberación del 21 % del fármaco encapsulado liberado después de 48 horas, en comparación con el fármaco libre que se liberó por completo después de solo 6 horas. Para la liofilización de las NP de Ca (OH) ₂ / PLGA, se obtuvo un resultado el mejor resultado con la combinación de 5% de (2-hidroxipropil) -β-ciclodextrina y 15% de D-manitol. Estas formulaciones pudieron ser resuspendidas de forma instantánea consiguiendo los parámetros originales. Desafortunadamente, para los NP de propionato de clobetasol / PLGA, no pudimos lograr una combinación adecuada de crioprotectores y condiciones de liofilización óptimas. Usando la microscopía confocal, se demostró que tanto el Ca (OH) ₂ / PLGA como el propionato de clobetasol / PLGA NP tenían una mejor profundidad y área de penetración dentro de los túbulos dentinarios en comparación con el fármaco libre. Además, los NP mostraron valores más altos de intensidad de fluorescencia media (mean fluorescence intensity, MFI) y densidad integrada en comparación con el fármaco libre. Al evaluar la eficacia antibacteriana de las NP de Ca (OH) ₂ / PLGA utilizando la prueba de difusión en agar, se observó que las NP mostraban zonas claras máximas de inhibición del crecimiento alrededor de los papeles de filtro comparables solo al grupo positivo de antibióticos. Además, se midió la concentración mínima inhibitoria (CMI) de las NP con respecto a la inhibición del crecimiento bacteriano para 3 especies bacterianas. Se observó que después de 24 horas de incubación, las NP inhibieron el crecimiento bacteriano en todas las concentraciones probadas. Se realizaron estudios para medir la capacidad antiinflamatoria de las NPs de propionato de clobetasol /PLGA, para lo cual se utilizaron test ELISA para evaluar la respuesta de los macrófagos en la liberación de citoquinas inflamatorias en presencia de las NP. Se observó que las liberaciones de TNF-α se redujeron considerablemente a cantidades casi indetectables con NPs en comparación con el control negativo (LPS), mostrando resultados similares e incluso menores que el control positivo (TCP) después de 48 horas. Sin embargo, se obtuvo la liberación de IL-1β en cantidades mayores que eran similares al control positivo de TCP y menores que al grupo de control negativo de LPS. La liberación de citoquinas inflamatorias de IL-1β y TNF-α de los macrófagos pretratados con LPS no se redujo con las NP en ninguna concertación probada a límites por debajo de las cantidades obtenidas por los macrófagos pretratados con LPS o el grupo de control positivo de TCP después de 48 horas. Conclusiones: En el presente estudio, las NP de PLGA encapsulando Ca(OH)₂ y las NP de PLGA encapsulando propionato de clobetasol han sido optimizadas y caracterizadas con éxito, y se ha probado su eficacia terapéutica con el objetivo de aumentar el efecto antibacteriano y antiinflamatorio. La penetración de las mismas en áreas de anatomía complicada del conducto radicular (túmulos dentinarios) ha sido demostrada, debido al tamaño nanoscópico de las mismas. Sin embargo, aún se requieren más estudios futuros para que las NP formuladas puedan ser utilizados en una condición clínica.

Objetivo: O objetivo do presente estudo foi desenvolver uma medicação intracanal contendo hidrocloreto de polihexametileno guanidina (PHMG) e hidróxido de cálcio Ca(OH)2, avaliando as suas propriedades e eficácia antimicrobiana. Métodos: O material foi formulado a partir da associação de 2% de PHMG ao pó de hidróxido de cálcio associado ao veículo propilenoglicol. O material foi avaliado pelos testes de análise antimicrobiana, escoamento, espessura de película, análise de pH e liberação de cálcio. Resultados: Os resultados foram analisados através do teste ANOVA de uma via, ANOVA de duas vias e teste tukey, com nível de significância de 5%. A atividade antimicrobiana com a associação de hidrocloreto de polihexametileno guanidina (PHMG) mostrou-se eficaz para Enterococcus faecalis. No teste de escoamento, o hidróxido de cálcio associado com o propilenoglicol mostrou um escoamento maior do que quando associado com o hidrocloreto de polihexametileno guanidina (PHMG) (p˂ 0,05). No teste de espessura de película os grupos não apresentaram diferença. Na análise de pH, os grupos variaram a alcalinidade nos tempos avaliados, durante o período de 28 dias (pH entre 7,5 – 11,5). Na liberação de cálcio, o uso do antimicrobiano hidrocloreto de polihexametileno guanidina (PHMG) não interferiu na liberação de cálcio do material. Conclusão: A adição de (PHMG) ao pó de hidróxido cálcio e ao veículo propilenoglicol não interferiu na liberação de cálcio, além de possuir efeito antimicrobiano, manteve o pH alcalino, não alterando a espessura de película, entretanto apresentou um menor escoamento do material.
Objective: The objective of the present study was to develop an intracanal medication containing polyhexamethylene guanidine hydrochloride (PHMG) and calcium hydroxide Ca (OH)2, evaluating its properties and antimicrobial efficacy. Methods: The material was formulated from the association of 2% PHMG with the calcium hydroxide powder associated with the propylene glycol vehicle. The material was evaluated by antimicrobial analysis, flow, film thickness, pH analysis and calcium release. Results: The results were analyzed through the one-way ANOVA, two-way ANOVA and tukey test, with a significance level of 5%. The antimicrobial activity with the combination of polyhexamethylene guanidine hydrochloride (PHMG) was shown to be effective for Enterococcus faecalis. In the flow test, the calcium hydroxide associated with propylene glycol showed a greater flow than when associated with polyhexamethylene guanidine hydrochloride (PHMG) (p<0.05). In the film thickness test, the groups showed no difference. In the pH analysis, the groups varied the alkalinity at the evaluated times, during the period of 28 days (pH between 7.5 - 11.5). In the release of calcium, the use of the antimicrobial polyhexamethylene guanidine hydrochloride (PHMG) did not interfere with the release of calcium from the material. Conclusion: The addition of (PHMG) to the calcium hydroxide powder and to the propylene glycol vehicle did not interfere with the release of calcium, besides having an antimicrobial effect, it maintained the alkaline pH, without altering the film thickness, however presented a lower material flow.

Projeto de Pós-Graduação/Dissertação apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
Um dos principais objetivos do tratamento Endodôntico é a tentativa de conseguir conduzir o sistema de canais radiculares a um ambiente de assepsia, sendo este conseguido através da eliminação dos microrganismos nocivos à cicatrização dos tecidos, permitindo assim a cura da infeção e posterior restabelecimento da função do dente. O tratamento endodôntico, seja preconizado numa ou em múltiplas sessões, visa a criação de condições ótimas para a obturação e selamento tridimensional dos canais radiculares. Assim, a seleção da modalidade de tratamento endodôntico terá de se basear, primeiramente, numa avaliação rigorosa do dente, propriamente dito, quanto à sua condição fisiopatológica pulpar e periapical, acessibilidade, caraterísticas morfológicas dos canais radiculares e restaurabilidade Uma das questões que mais se tem debatido é se o tratamento endodôntico numa sessão, possibilita que se atinjam tais condições, permitindo, portanto, alcançar os objetivos biológicos e mecânicos exigidos. Neste contexto, em que na atualidade paira a controvérsia e a incerteza sobre qual o procedimento mais indicado para a prática clínica, o objetivo deste trabalho foi, após efetuar uma revisão da literatura científica existente, tentar perceber se é mais indicado iniciar o tratamento e finaliza-lo na mesma sessão ou proceder a obturação na consulta seguinte. Hoje, devido aos avanços das técnicas de instrumentação e irrigação, que tem tornado o tratamento endodôntico mais eficaz num menor período de tempo, a sessão única é cada vez mais preconizada pelos profissionais. O sucesso será garantido se os procedimentos clínicos forem integralmente cumpridos e o tipo de modalidade escolhida resultar da reflexão das características de cada caso em particular. One of the main goals of Endodontic treatment is the attempt to achieve leading the root canal system to an aseptic environment, which is achieved through the elimination of the microorganisms that are harmful to the healing of tissues, allowing this way the healing of the infection and subsequent restoration of the tooth function. Endodontic treatment, whether recommended in one or in multiple sessions, aims to create optimal conditions for the tridimensional filling and sealing of the root canals. Thus, the selection of the type of endodontic treatment must be based, first, in a rigorous evaluation of the tooth itself, as far as its pathophysiological pulp and periapical condition, accessibility, morphological characteristics of the root canals and restorability are concerned. One of the most discussed issues is whether endodontic treatment in one session, enables one to get such conditions that allow the required mechanical and biological objectives to be achieved. In this context, in which nowadays hangs the controversy and the uncertainty about what the most suitable procedure for clinical practice is, the aim of this work, after carrying out a review of the existing scientific literature, was trying to understand whether it is more appropriate to start treatment and finish it in the same session or proceed with the filling in a second session. Today, due to the advances in the instrumentation and irrigation techniques, which have turned the endodontic treatment in a shorter period of time most effective, a Single Visit is increasingly recommended by health professionals. The success will be ensured if the clinical procedures are fully performed and if the type of modality chosen results of the reflection of the characteristics of each particular case.

Introdução: Materiais com modificações na formulação original do MTA, incluindo o NeoMTA Plus, têm sido desenvolvidos buscando melhorar suas propriedades físicoquímicas. O objetivo do presente estudo foi analisar a resposta do tecido ósseo de ratos Wistar frente ao implante de NeoMTA Plus em comparação com o MTA Angelus. Metodologia: 24 ratos foram anestesiados e uma broca de baixa rotação foi empregada para confeccionar três cavidades cirúrgicas no fêmur direito. As cavidades cirúrgicas foram preenchidas aleatoriamente com os materiais teste NeoMTA Plus e MTA Angelus ou deixada vazia (controle negativo). Após 7, 30 e 90 dias as características do reparo ósseo foram classificadas em escores com o auxilio de microscópio óptico. As comparações entre os grupos foram realizadas pelo teste de Friedman e as comparações entre os três períodos experimentais em cada grupo foram realizadas pelo teste de Kruskal-wallis, seguido pelo teste de Dunn. O nível de significância foi estabelecido em P<.05. Resultados: Não foram observadas diferenças estatísticas entre os materiais e o grupo controle nos 3 tempos experimentais. Em todos os grupos houve diferença estatisticamente significante entre os tempos de 7 e 30 dias e nenhuma diferença foi observada entre os tempos de 30 e 90 dias. Além disso, o reparo em 90 dias foi significativamente melhor do que em 7 dias nos grupos NeoMTA Plus e controle. Conclusões: O NeoMTA Plus demonstrou comportamento biológico satisfatório em contato direto com o tecido ósseo de ratos Wistar, apresentando resultados semelhantes aos grupos MTA Angelus e controle.
Introduction: Materials that alter the original formulation of MTA have been developed to improve physical-chemical properties, including NeoMTA Plus (NMTAP). The aim of the present study was to analyze bone tissue reactions to NMTAP compared to MTA Angelus (MTA-A). Methods: 24 animals were anesthetized and a slow-rotation bur was used to create three surgical cavities in their right femur. Surgical cavities were randomly designated to NMTAP, MTA-A and negative control (empty cavity) groups. After 7, 30, and 90 days histological analysis of the characteristics of bone repair were classified in scores. Friedman’s test performed intergroup comparisons and Kruskal-Wallis test, followed by the Dunn’s post hoc test, compared the three experimental periods in each group. The significance level was set at P<.05. Results: No differences were found between the materials and control group in each experimental period. In all groups, the bone tissue repair improved from 7 to 30 days and there was no difference from 30 to 90 days. Moreover, the repair at 90 days was significantly better than at 7 in NMTAP and control groups. Conclusions: NeoMTA Plus showed satisfactory biological behavior when in direct contact with rat bone tissue, presenting repair characteristics similar to those produced by MTA Angelus and by the control group.

O presente estudo avaliou ex vivo a permeabilidade das paredes dentinárias de canais radiculares, após a remoção de três diferentes associações de materiais obturadores. Para tanto, 36 pré-molares uni-radiculares extraídos, com comprimento e aspectos anatômicos semelhantes, tiveram a cirurgia de acesso à câmara pulpar realizada, preparo do canal radicular até instrumentos ProTaper F4 e obturação com uma das seguintes associações de materiais: G1 - guta-percha e cimento Fill Canal (n=10); G2 - guta-percha e cimento AH-Plus (n=10); G3 - Resilon e cimento Epiphany (n=10). Seis espécimes tiveram seus canais preparados mas não foram obturados para fins de controle positivo. Após 24 horas em estufa, os canais foram desobturados, com instrumentos rotatórios NRT para retratamento, limas do tipo K #40 e solvente de óleo de casca de laranja. Terminada a desobturação, os espécimes foram impermeabilizados e submetidos ao teste de impregnação de azul de metileno 1% por 24 horas. Os dentes foram então lavados em água corrente por 24 horas, tiveram sua coroas amputadas e as raízes seccionadas horizontalmente em fatias de 1mm. Uma secção de cada terço radicular foi selecionada e fotografada, e o percentual de dentina corada em cada secção foi calculada por meio de um software de análise gráfica. Os resultados demonstraram diferença significativa entre os grupos experimentais e o grupo controle (p<0,05), contudo, não houve diferença estatística entre os grupos experimentais (p>0,05). Concluiu-se assim que o tipo de material obturador utilizado não influencia na permeabilidade dentinária após sua remoção.
The purpose of this study was to evaluate ex vivo the permeability of root canal dentin walls after the removal of three different combinations of filling materials. To this end, 36 extracted human single-rooted premolars, with similar length and anatomy, had surgery access to the pulp chamber, root canal preparation was performed to F4 ProTaper instruments and filling with one of the following associations of filling materials: G1 - gutta-percha and Fill Canal cement (n = 10); G2 - gutta-percha and AH Plus cement (n = 10); G3 - Resilon cones and Epiphany cement (n = 10). Six specimens were prepared but its canals were not filled for positive control. After 24 hours at 37 ° C, the canals were desobturated, making use of NRT rotary instruments , # 40 K-type files and orange oil based solvent. After the removal of the filling material, specimens were sealed and tested for impregnation of dye in 1% methylene blue for 24 hours in the absence of vacuum. The teeth were then washed in running water for 24 hours, had their crowns amputated and the roots sectioned horizontally into 1 mm slices. For each root third , one section was selected and photographed, the images were stored on computer and the percentage of stained dentin in each section was calculated using a graphical analysis software. The results showed a statistically significant difference between experimental groups and control group (p <0.05). However, there was no statistical difference between experimental groups (p> 0.05). Thus, it was concluded that the type of filling material does not influence dentin permeability after its removal.

Thesis (M.S.)--West Virginia University, 2002.
Title from document title page. Document formatted into pages; contains viii, 51 p. : ill. Includes abstract. Includes bibliographical references (p. 39-42).

Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains viii, 59 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 33-38).

This thesis was aimed at investigating the physical-chemical properties and the behaviour in physiological environment of two classes of bioceramics: calcium silicate-based dental cements and alumina-based femoral heads for hip joint prostheses. The material characterization was performed using spectroscopic techniques such as that allow to obtain information on the molecular structure of the species and phases present in the analyzed samples. Raman, infrared and fluorescence spectroscopy was principally used. Calcium silicate cements, such as MTA (Mineral Trioxide Aggregate), are hydraulic materials that can set in presence of water: this characteristic makes them suitable for oral surgery and in particular as root-end filling materials. With the aim to improve the properties of commercial MTA cements, several MTA-based experimental formulations have been tested with regard to bioactivity (i.e. apatite forming ability) upon ageing in simulated body fluids. The formation of a bone-like apatite layer may support the integration in bone tissue and represents an essential requirement for osteoconduction and osteoinduction. The spectroscopic studies demonstrated that the experimental materials under study had a good bioactivity and were able to remineralize demineralized dentin. . Bioceramics thanks to their excellent mechanical properties and chemical resistance, are widely used as alternative to polymer (UHMWPE) and metal alloys (Cr-Co) for hip-joint prostesis. In order to investigate the in vivo wear mechanisms of three different generations of commercial bioceramics femoral heads (Biolox®, Biolox® forte, and Biolox® delta), fluorescence and Raman spectroscopy were used to investigate the surface properties and residual stresses of retrieved implants. Spectroscopic results suggested different wear mechanisms in the three sets of retrievals. Since Biolox® delta is a relatively recent material, the Raman results on its retrievals has been reported for the first time allowing to validate the in vitro ageing protocols proposed in the literature to simulate the effects of the in vivo wear.

This thesis was aimed at investigating the physical-chemical properties and the behaviour in physiological environment of two classes of bioceramics: calcium silicate-based dental cements and alumina-based femoral heads for hip joint prostheses. The material characterization was performed using spectroscopic techniques such as that allow to obtain information on the molecular structure of the species and phases present in the analyzed samples. Raman, infrared and fluorescence spectroscopy was principally used. Calcium silicate cements, such as MTA (Mineral Trioxide Aggregate), are hydraulic materials that can set in presence of water: this characteristic makes them suitable for oral surgery and in particular as root-end filling materials. With the aim to improve the properties of commercial MTA cements, several MTA-based experimental formulations have been tested with regard to bioactivity (i.e. apatite forming ability) upon ageing in simulated body fluids. The formation of a bone-like apatite layer may support the integration in bone tissue and represents an essential requirement for osteoconduction and osteoinduction. The spectroscopic studies demonstrated that the experimental materials under study had a good bioactivity and were able to remineralize demineralized dentin. . Bioceramics thanks to their excellent mechanical properties and chemical resistance, are widely used as alternative to polymer (UHMWPE) and metal alloys (Cr-Co) for hip-joint prostesis. In order to investigate the in vivo wear mechanisms of three different generations of commercial bioceramics femoral heads (Biolox®, Biolox® forte, and Biolox® delta), fluorescence and Raman spectroscopy were used to investigate the surface properties and residual stresses of retrieved implants. Spectroscopic results suggested different wear mechanisms in the three sets of retrievals. Since Biolox® delta is a relatively recent material, the Raman results on its retrievals has been reported for the first time allowing to validate the in vitro ageing protocols proposed in the literature to simulate the effects of the in vivo wear.

Este estudo teve como objetivo avaliar a citotoxicidade, biocompatibilidade e perfil osteoindutor de um novo material a base de MTA (MTA Flow) comparado ao AH plus e MTA fillapex. A viabilidade celular foi avaliada em células-tronco do ligamento periodontal pelo teste MTT. A resposta inflamatória e o perfil osteoindutor foram avaliados em tecido conjuntivo de 24 ratos machos (Rattus norvegicus albinus, Rodentia, Mammalia da linhagem Wistar), pesando entre 300 e 350g. Os animais foram divididos em 4 grupos experimentais. Foram implantados 4 tubos de polietileno no dorso de cada animal, sendo um vazio e outros três preenchidos com um dos materiais. Após 7, 30 e 60 dias, 8 animais foram mortos com anestésico inalatório. O tubo e o tecido subcutâneo adjacente foram removidos e fixados em solução de formalina a 10%. O material foi analisado histológicamente quanto ao processo inflamatório, condensação fibrosa e presença de abscesso. Posteriormente, realizou-se a análise imunoistoquímica para identificação de colágeno I, osteopontina, sialoproteina óssea e proteína morfogentica óssea-4 (BMP-4). Os dados foram analisados estatisticamente pela ANOVA, complementado pelo teste de Tukey usando SPSS 15.0. O MTA Flow mostrou não ser citotóxico e ter excelente biocompatibilidade com menor reação inflamatória no tecido subcutâneo de ratos em comparação com AH Plus e MTA Fillapex. Além disso, o MTA Flow mostrou ser capaz de estimular o processo mineralização, sendo uma vantagem em relação aos outros materiais testados.
This study aimed to evaluate the cytotoxicity, biocompatibility and osteoinductive profile of a new MTA based material (MTA Flow) compared to AH plus and MTA fillapex. Cell viability was evaluated in periodontal ligament stem cells by the MTT test. The inflammatory response and the osteoinductive profile were evaluated in the connective tissue of 24 male rats (Rattus norvegicus albinus, Rodentia, Mammalia of the Wistar line) weighing between 300 and 350g. The animals were divided into 4 experimental groups. Four polyethylene tubes were implanted on the back of each animal, one empty and another three filled with one of the materials. After 7, 30 and 60 days, 8 animals were killed with inhaled anesthetic. The tube and adjacent subcutaneous tissue were removed and fixed in 10% formalin solution. The material was analyzed histologically for the inflammatory process, fibrous condensation and presence of abscess. Subsequently, the immunohistochemical analysis was performed to identify collagen I, osteopontin, bone sialoprotein and bone morphogenetic protein-4 (BMP-4). Data were analyzed statistically by ANOVA, complemented by the Tukey test using SPSS 15.0. MTA Flow was shown to be non-cytotoxic and to have excellent biocompatibility with lower inflammatory reaction in rat subcutaneous tissue compared to AH Plus and MTA Fillapex. In addition, the MTA Flow showed to be able to stimulate the mineralization process, being an advantage over the other materials tested.

The aim of this study was to determine the trends in protocol, success rates, and consistency in follow up of revascularization procedures in a controlled environment. Patients of the Virginia Commonwealth University School of Dentistry were identified who were offered revascularization therapy as a treatment option on immature permanent teeth from January 1, 2010 to May 31, 2017. A total of 77 patients and 78 teeth were evaluated for revascularization therapy. For patients accepting treatment, records were reviewed for outcome assessment and consistency of follow up. A total of 30 patients (31 teeth) were treated following revascularization protocols, with only 20 patients (21 teeth) returning for follow up. Six of the 21 teeth needed some form of additional therapy due to patients remaining symptomatic, however 15/21 exhibited varying levels of success. Recall rate was 67.7%. With a success rate of 71.4%, revascularization therapy should continue to be considered for all patients with teeth having necrotic pulps and immature root apices. However, changes to recall protocols need to be improved in order to better monitor the status of teeth that undergo revascularization therapy.

Introduction: The need for endodontic treatment in dental care is a well-established in the literature. A substantial perceived need for referring endodontic cases to endodontic specialists has been reported. In order to improve the success rate for endodontic treatment by general dental practitioners (GDPs), the referral of the more complex cases to an experienced endodontist should be made possible in the best interest of the patient. In order to be able to refer such cases appropriately, two requirements need to be satisfied. Firstly, GDPs need to be able to predictably identify the cases with higher complexity and higher risk of adverse outcomes, then treat or refer to the appropriate practitioner. Secondly, there needs to be a sufficient number of endodontic specialists or endodontic workforce with appropriate referral pathways available. Aims: The aims of this project are therefore twofold. First is to develop a valid and reliable digital assessment tool that can help GDPs assess and classify complex non-surgical root canal treatments (NSRCT). Secondly is to determine the prevalence of endodontic complexity in general dental practice to help assess the level of need for endodontic treatment, training and therefore inform commissioning within the health system. Methodology: The first part of the research focused on the development of the Endodontic Complexity Assessment Tool (E-CAT). This included a review of the current literature, iterative analysis of the complexity factors and the development of digital software to enhance the tool’s efficiency and practicality. Inter-observer and intra-observer reliability studies were conducted with 15 dentists utilising the tool to assess 15 clinical cases and repeating the experiment 9 months later. External validation of the tool was sought with a panel of 35 endodontists to assess the same 15 cases. The consensus of the panel on the complexity of each case was considered as “gold standard” assessment and was compared to the outcome of achieved by the E-CAT. For the prevalence study, 30 fully qualified dentists working within general dental practice across the UK were recruited. Each dentist assessed 10-15 consecutive potential endodontic cases as encountered in their day-to-day clinical practice. The data was collected using the online E-CAT. The tool allowed the data to be recorded into a secure database. Information on tooth-related factors, systemic factors, oral diagnosis and patient-related factors was recorded. Three levels of complexity were defined for the analysis; class I (uncomplicated), class II (moderately complicated) and class III (highly complicated). The data was analysed to express period prevalence with a 95% confidence interval using SPSS statistical software. Results: The E-CAT was successfully developed with a total of 22 complexity criteria; the tool was hosted on a secure university server under the domain of www.e-cat.uk. The inter-user and intra-user reliability was found to be 0.80 and 0.90 respectively. The consensus of the endodontists panel matched to all 15 cases assessed. The inter-examiner correlation of the panel was 0.51. The average time to assess a case was 01:36 minute. A total of 435 endodontic cases were recorded for the prevalence study. The distribution of complexity over classes I, II and III was 39.8%, 31.9% and 28.3% respectively. History of previous root canal intervention formed 22.9% of the cases encountered. The majority of the cases (64.4%) appeared to have < 15 degree root curvature, 30.6% had 15-40 degree curvature and only 4.0% had > 40° curvature. Teeth with existing extra-coronal restorations formed 18.8% of the cases encountered. Radiographically, visible or moderately reduced canal space was reported in 76.9% of the cases, while 20.9% had severely reduced canal space and only 3.2% were perceived to have invisible canal space. History of trauma was encountered in 8.9% of the evaluated cases. Conclusion: The E-CAT provides an efficient and reliable platform to assess the complexity of NSRCT. The results obtained in the prevalence study provide a good resource and databank for researchers, public health commissioners and academic institutions to access wide range of information concerning the prevalence and distribution of endodontic complexity. The results obtained in this research indicate a possible shortage of endodontic specialist service in the UK, especially within the National Health Service.

POTENTIAL ANTIMICROBIAL METHODS FOR PROVISIONALIZING TEETH AFTER ENDODONTIC TREATMENT By Laura T. Garden, DDS A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, 2018 Thesis Advisor: Garry Myers, DDS Department of Endodontics Objective:To evaluate the effectiveness of a Chlorhexidine soaked cotton pellet on bacterial leakage. Methods: Fifty-one extracted teeth, including six controls, were instrumented, obturated, and sealed with either a cotton pellet (CP), 2% Chlorhexidine soaked cotton pellet (CHX), or a Permaflo orifice barrier (OB). Each root was suspended between two chambers: the coronal chamber inoculated with brain heart infusion broth and colony-forming units of Enterococcus faecalis, the apical chamber with brain heart infusion broth and phenol red. The latter was checked daily for turbidity, indicating bacterial leakage. Results: All open and closed control groups had leaked by day 7. The average CP tooth survived for 13.1 days whereas the CHX and OB teeth leaked by an average of 5.8 days. Conclusion:There is insufficient evidence to support the use of a Chlorhexidine soaked cotton pellet. The results were not as expected and the study design should be re-evaluated.

Trabalho apresentado à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Medicina Dentária
Introdução: O retratamento endodôntico é o tratamento endodôntico de um dente que apresenta periodontite apical recorrente ou recidivante. A lesão pós-tratamento é originada por diversos factores tais como: trauma, reacção a corpo estranho, infecção extra-radicular, quisto verdadeiros, problemas iatrogénicos e microrganismos persistentes ou recorrentes intracanalares. O retratamento não cirúrgico é muitas vezes associado ao cirúrgico. Objectivo: Identificar as causas de fracasso do tratamento endodôntico e as distintas opções de tratamento. Material e Métodos: Através do motor de busca Pub-med, utilizando as palavras-chave, “Surgical endodontic retreatment”, “Endodontic retreatment”, “endodontic filling materials”, “extrusion of endodontic obturation materials”, “endodontic failure, “calcifying odontogenic cyst”, “Tooth reimplantation” foram encontrados 261 artigos. Os artigos que obedeciam aos critérios seleccionados foram 25. Conclusão: A escolha do retratamento não cirúrgico é sempre a 1º opção, pois permite solucionar a maioria dos fracassos quando um tratamento endodôntico não funciona. Para além disso, oferece mais benefícios e menor risco em certos casos, é menos invasivo que o cirúrgico, havendo menores danos pós-operatórios. Em casos em que o clínico tem dificuldade em eliminar os microrganismos persistentes no canal, a escolha do tratamento poderá passar pelo retratamento endodôntico cirúrgico. Introduction: The endodontic retreatment is endodontic treatment of a tooth, presenting apical periodontitis recurrent or relapsed. The lesion after treatment is caused by several factors such as trauma, foreign body reaction, extra-radicular infection, true cyst, iatrogenic problems and persistent or recurrent intracanal microorganisms. The non-surgical retreatment is often associated with surgery. Aim: Identify the causes of failure of endodontic treatment and the different treatment options. Methods and Material: Through search engines like Pub-med, using as keywords, “Surgical endodontic retreatment”, “Endodontic retreatment”, “endodontic filling materials”, “extrusion of endodontic obturation materials”, “endodontic failure, “calcifying odontogenic cyst”, “Tooth reimplantation”. it was found 261 articles. The articles that conformed to the criteria selected were 25. Conclusion: The choice of nonsurgical retreatment is always the 1st option because it allows solving most of the failures, when a root canal treatment does not work. In addition, it offers more benefits and less risk in some cases is less invasive than surgery, with less postoperative trauma. In cases where the clinician has difficulty in eliminating the microorganisms persisting in the channel, the choice of treatment can be obtained by surgical endodontic retreatment.

Apical periodontitis, an acute or chronic inflamination around the apex of the tooth, is caused by bacteria in the root canal. In Sweden the dentists devote around 10X of their total time to treating this disease. The treatment usually requires 3 to 5 sessions. The treatment may fail in up to 25X of the cases. In the present study various treatment regimens were evaluated. One hundred and forty singlerooted teeth with apical periodontitis were treated. The importance of mechanical instrumentation, irrigating solutions and antibacterial dressings in eliminating bacteria from the infected root canals was studied using bacteriological techniques. The healing of the apical periodontitis after treatment was followed for 2 to 5 years on recall radiographs. Bacteria were found in all 140 root canals at the beginning of the treatment. Most of these bacteria were anaerobes and they represented a restricted group of bacteria compared to the bacteria present at other sites in the oral cavity. Mechanical instrumentation with files and reamers in combination with saline irrigation reduced the number of bacterial cells in the root canal 100- to 1000-fold during one treatment session. Bacteria could be eliminated from about half the number of root canals if this treatment was performed at 4 sessions. Mechanical instrumentation and irrigation with 0.5X or 5X sodium hypochlorite solutions or with the 5X solution in combination with 15X EDTA solution wa3 more efficient and the bacteria were eliminated from about half the treated canals after one treatment session. The bacteria which persisted in the root canal after this treatment usually increased in number during the interval up to the next session and reached levels which were often as high as in the initial sample at the previous session. All bacteria persistent in the root canals after the previous treatment regimens were with 2 exceptions eliminated by dressing the root canals for 1 to 2 months with calcium hydroxide paste. Thirty-four out of 35 root canals treated at the first session with mechanical instrumentation, irrigation with sodium hypochlorite solution and dressed with calcium hydroxide paste were free of bacteria at the second session. Calcium hydroxide paste was superior to camphorated phenol and camphorated paramonochlorophenol as dressing. Healing of 79 out of the 140 treated teeth was followed for 2 to 5 years. The majority of the lesions healed completely or decreased in size in such a way that they could be expected to heal. There was no or only an insignificant decrease in the size of the lesions in 5 cases. In 2 of these cases bacteria were demonstrated in the periapical tissues and in a third case dentin chips. Periapical lesions may thus fail to heal in a few cases due to an establishment of bacteria outside the root canal, and in that site the bacteria are inaccessible to conventional endodontic treatment. The present study showed that treatment of the majority of infected non-vital teeth can be completed in only 2 sessions, if mechanical instrumentation, sodium hypochlorite irrigation and calcium hydroxide dressing are combined.

Diss. (sammanfattning) Umeå : Umeå universitet, 1986, härtill 5 uppsatser.

digitalisering@umu

The success of root canal treatment is dependent on canal debridement, disinfection and impervious obturation of the root canal system. The material most commonly used for root canal obturation is the trans-isomer of isoprene, known as gutta-percha. Limitations of gutta-percha as a root canal obturation material include lack of flexibility and potential for degradation caused by eugenol or other components of root canal sealers and restorative materials. A detailed study on the development, characterisation and in vitro evaluation of a composite, tailor-made to function as a root canal obturation material as well as serve as a “carrier” for delivering a root canal obturation material was undertaken. Polymer composites comprising of low density polyethylene (LDPE), hydroxyapatite (HA) or 45S5 Bioglass® (BAG) and strontium oxide (SrO) were developed via extrusion using a single screw extruder and drawn into the desired shape using appropriate ‘dies’ and optimised based on their physical and mechanical properties. The polyethylene in the composite showed no evidence of degradation post extrusion as confirmed by FTIR spectroscopy, the thermal analysis showed that the HA/PE composites had melting point of 110.5-111.2°C, much higher than that of gutta-percha (52°C). The tensile strength and elastic modulus of the silanated HA/PE composites were significantly higher than those of gutta-percha (p<0.0001) under dry conditions and after storage in simulated body fluid. Furthermore, the interaction of eugenol did not produce any change in the experimental HA/PE composites whereas gutta-percha showed a significant increase in the weight. The radiological contrast of the silanated HA/PE fibres was adequate to allow their use as a root canal obturation material. Bioglass® reinforced low density polyethylene with SrO composites are promising obturation materials for endodontic treatment. They exhibited superior stiffness in comparison to gutta-percha with excellent biocompatibility and bioactivity. An enhanced proliferation of human osteoblast cells was also observed.

Thesis (M.S.)--West Virginia University, 1999.
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This study determined if any of four endodontic solutions would have a softening effect on resorcinol-formalin paste and if there were any differences in the solvent action between these solutions. Resorcinol, formalin and zinc oxide were mixed and allowed to set for 30 days. The solutions tested were 0.9% sodium chloride, 5.25% NaOCl, chloroform and Endosolv R. Seven samples per solution were tested and an additional seven samples served as controls. Each sample was saturated with one of the solutions and the depth of penetration was tested at 1 min, 2 min, 5 min, 10 min and 20 min using a dial strain gauge. At 2 minutes, NaOCl and sodium chloride had significantly greater penetration than the other groups (p-values < 0.0010). Sodium hypochlorite was superior to all other groups after 5 minutes. This study showed that both sodium chloride and NaOCl exhibited a significant softening effect within two minutes.

Solvents have been used in endodontic retreatment for a long time and the dissolving effect is well proven. Latterly chloroform has come in a bad light due to its possible carcinogenicity. Despite the negative health effect it is still used in dental environment. Other more biocompatible solvents have now reached the market and tests should be performed to evaluate the softening efficacy. The purpose of this in-vitro study was to evaluate the softening efficacy of four different solvents used in endodontics; chloroform, eucalyptol, tetrachloroethylene, orange-oil and a control group. 100 simulated canals filled with gutta-percha, epoxy amine resin based sealer, zinc oxide eugenol based sealer and non eugenolcalcium hydroxide based sealer were tested with hardness measurement before and after two minutes exposure time of medicament. Non-eugenol calcium hydroxide failed to set and was excluded from the test. A Shore A durometer was used to evaluate the hardness of the materials and all data was first analyzed with Kruskal-Wallis test and then Mann-Whitney test to compare with control group. With a digital camera connected to a microscope we also took pictures to compare the impressions with the different medicaments. The result showed that chloroform and tetrachloroethylene is significant better to soften gutta-percha than control group (p < 0.05) but only chloroform significant better than control group to soften epoxy amine resin based sealer and zinc oxide eugenol based sealer (p < 0.05). Even if the result was significant, we cannot draw any conclusions due to small sample size.

O objetivo deste estudo foi avaliar o pH e a liberação de íons cálcio dos cimentos AH Plus, MTA Fillapex e Sealapex, em diferentes períodos, quando empregados em obturações de canais radiculares, bem como, a qualidade das obturações, após 1 ano de realizadas. O pH e a liberação de íons cálcio foram avaliados por meio de um peagômetro e espectrofotômetro de absorção atômica, respectivamente. A qualidade das obturações foi avaliada por meio de um estereomicroscópio. Cento e vinte e quatro pré-molares inferiores humanos extraídos, unirradiculados, foram divididos em 01 grupo controle e 02 grupos experimentais, de acordo com a padronização do diâmetro do forame apical. Em seguida, os 02 grupos experimentais foram divididos em 4 subgrupos, considerando as técnicas de instrumentação e obturação empregadas. Após o preparo dos canais radiculares cada subgrupo teve o número de dentes divididos por dois, formando novos subgrupos, de acordo com os cimentos obturadores utilizados. Imediatamente após a obturação, a raiz de cada dente foi imersa em 15 mL de água ultrapura para avaliação do pH e liberação de íons cálcio nos seguintes períodos: 1 h, 1, 3, 7, 30, 180 e 365 dias, após a obturação. Após o período de 1 ano, os dentes foram seccionados transversalmente a 2, 4, 6 mm do forame apical para análise da qualidade das obturações, analisando-se a porcentagem de cimento, guta-percha e espaços vazios na massa obturadora. Os cimentos apresentaram pH neutro, porém, aos 180 dias, os valores mostraram um ligeiro aumento quando utilizados em canais com forames de diâmetro 0,25 mm. Quando utilizados em canais com forames de diâmetro 0,45 mm, o pH mostrou-se com valores maiores para todos os períodos sem distinção do cimento. Todos os cimentos liberaram íons cálcio, com menores valores para o AH Plus. Na estereomicroscopia, observaram-se variações nas porcentagens de cimento e guta-percha, considerando-se os diâmetros foraminais e técnicas obturadoras, e porcentagem insignificante de espaços vazios.
The objective of this study was to evaluate the pH and calcium ion release of AH Plus, MTA Fillapex and Sealapex cements at different time periods when used in root canal obturations, as well as the quality of the obturations one year after being performed. The pH and calcium ion release were evaluated by means of a pH meter and an atomic absorption spectrophotometer, respectively. The quality of the obturations was evaluated using a stereomicroscope. One hundred and twenty-four extracted human uniradicular mandibular premolars were divided into 1 control and 2 experimental groups, according to the standardization of the apical foramen diameter. Next, the 2 experimental groups were divided into 4 subgroups, considering the instrumentation techniques and obturations employed. After the preparation of the root canals, each subgroup had the number of teeth divided by two, forming new subgroups, according to the sealers used. Immediately after the obturation, the root of each tooth was immersed in 15 mL of ultrapure water for the evaluation of the pH and calcium ion release in the following time periods: 1 hr, 1, 3, 7, 30, 180 and 365 days after the obturation. After the period of one year, the teeth were transversely sectioned at 2, 4 and 6 mm from the root apex to examine the quality of the obturations, analyzing the percentage of cement, gutta-percha and voids in the obturator mass. The cements presented a neutral pH, which showed slightly increase as of 180 days when used in canals with foramens of 0.25 mm diameters. When used in canals with foramens with diameters of 0.45 mm, the pH presented higher values in all periods for all cements. All cements released calcium ions, with lower values for the AH Plus. In the stereomicroscopy, there were variations in the percentages of cement and gutta-percha, considering the foraminal diameters and obturation techniques and an insignificant percentage of voids.

Este trabalho teve como objetivo preparar e caracterizar um compósito de colágeno com silicato e hidroxiapatita a ser possivelmente utilizado para capeamento pulpar direto e em pulpotomia como material endodôntico em prevenção ao tratamento radical de canais radiculares que em virtude de suas anatomias dificultam a utilização de biomateriais no interior dos mesmos. Embora materiais para este fim estejam disponíveis no mercado, na maioria dos casos não são isentos de agressão na zona do reparo. O colágeno utilizado foi do tipo I na forma aniônica que foi misturado com silicato (cimento Portland branco) e hidroxiapatita em proporções variadas. Os materiais obtidos foram caracterizados por técnicas de calorimetria exploratória diferencial (DSC), termogravimetria (TG), microscopia eletrônica de varredura (MEV), espectrometria de dispersão de energia de Raios-X (EDX) e espectroscopia na região do infravermelho (FTIR). A presença de colágeno no compósito foi demonstrada por transições térmicas típicas daquelas encontradas para o colágeno do tipo I ('APROXIMADAMENTE' 48 graus Celsius), independentemente da proporção utilizada, e também por MEV, onde as fibras colagênicas também puderam ser observadas interligando as partículas de silicato. Em função das quantidades de colágeno utilizadas, a composição química dos compósitos foi praticamente aquela descrita para o silicato inicial utilizado. Estes resultados mostraram que a estrutura da matriz colagênica nos compósitos estudados não foi alterada, uma característica importante para a utilização dos materiais propostos na endodontia objetivando uma reparação dos tecidos envolvidos de uma forma “mais natural”
In this work was prepared and characterized collagen composites with silicate and hydroxyapatite for pulp capping; post pulpotomy usage, as endodontic material. Even though materials for this purpose are available, in most case they suffer degradation in the repair zone when. Was used type I collagen in the form anionic mixed with silicate (white Portland cement) and hydroxyapatite in various proportions. The materials were characterized by standard differential scanning calorimetry (DSC), thermogravimetry (TG), scanning electronic microscopy (SEM) and infrared spectroscopy (FTIR), energy dispersion X-Ray (EDX). The presence of the collagen in the composite was checked via the thermal transitions typical for collagen type I ('APPROXIMATE' 48 Celsius degrees), independently of the proportion used and also via MEV, in which the collagenic fibers could also be seen interconnecting the silicate particles. For the amounts of collagen used, we find the chemical composition of the composites is essentially the same as that of the silicate we started with. This results showed that the structure of the collagenic matrix in the composite studied is not altered – an important feature for the use of the proposed materials in endodontic applications aiming at repairing the relevant tissues in a “more natural way”

O emprego da solução de hipoclorito de sódio em Endodontia data de 1936 quando Walker a introduziu na forma de soda clorada. Desde então, essa veio a se constituir na solução mais bem aceita como irrigante para fins endodônticos. Nos últimos anos, atribuições de grande importância relativas ao desempenho das soluções de hipoclorito de sódio, têm sido referidas ao controle do seu pH. Este trabalho tem por objetivo avaliar a resposta inflamatória do tecido conjuntivo do dorso de ratos frente ao emprego de soluções de hipoclorito de sódio em diferentes concentrações e valores de pH. Para tanto, 36 ratos receberam quatro feridas circulares confeccionadas por um punch. Sobre cada três dessas feridas foi gotejada uma solução diferente, enquanto que a última foi utilizada para controle. Os tratamentos foram realizados em triplicata. Após a irrigação das feridas, os ratos foram sacrificados em 3, 7 e 14 dias. Os fragmentos foram fixados e corados com hematoxilina e eosina para análise histológica. A análise histológica mostrou que aos 14 dias quase todos os espécimes encontravam-se totalmente epitelizados, com fenômenos inflamatórios somente no tecido conjuntivo subjacente, com exceção do grupo no qual foi utilizado a solução de hipoclorito de sódio 5% pH 11.
Sodium hypochlorite has been used as an endodontic irrigant since 1936, when Walker used it as Sodium Chlorine. Since then it has became the most well acceptable endodontic irrigant. During the last few years many studies have reported the importance of pH control. This study evaluates the inflammatory response of some endodontic irrigations solutions in the subcutaneous connective tissue of mice. Thirty six mice were obtained from the Biomedical Sciences Institute at the University of São Paulo. Their backs were divided in four quadrants and each quadrant was injured with an 8 mm punch. Three of these wounds were submitted to differents solutions, while the fourth was used as a control. This experiment was done in triplicate. After wounds irrigation mice were sacrificed at 3, 7 and 14 days. The samples were fixed on formol 10% and histologically analyzed after hematoxylin and eosin staining. At 14 days all wounds were covered with epithelium with a mild inflammatory infiltrate in the subjacent connective tissue, excepted the group that sodium hypochlorite 5% pH 11 was used. Endodontic; Sodium Hypochlorite; Inflamation.

O objetivo deste estudo foi avaliar a resistência à flexocompressão (flambagem) de instrumentos endodônticos empregados no cateterismo de canais radiculares atresiados e se esta varia conforme o comprimento. Flambagem é a deformação lateral apresentada por um instrumento quando submetido a uma força compressiva na direção de seu longo eixo. Foram utilizados instrumentos endodônticos C+File n 10, K-File n 10 (Dentsply-Maillefer, Suíça); CC+ n 10 e C-Pilot n 10 (VDW, Alemanha), HI-5 n 10 (Miltex, EUA), Pathfinder CS K2 e Pathfinder SS (SybronEndo, EUA), sendo dez amostras de cada marca comercial em diferentes comprimentos. As dimensões dos instrumentos, tais como diâmetros, comprimento útil, comprimento da parte de trabalho, conicidades, ângulos de inclinação das hélices, ângulo da ponta, forma de seu vértice e presença de ângulo de transição foram determinadas por meio de um microscópio óptico com dispositivo micrométrico acoplado a um computador (Pantec, Panambra, Brasil). Detalhes da forma das pontas e forma das seções retas transversais foram obtidas por meio de um microscópio eletrônico de varredura (MEV - JEOL, JSM-5800, Tókio, Japão). O ensaio de flambagem foi realizado empregando-se uma máquina de ensaio universal (EMIC, DL 10.000, Paraná) e consistiu na aplicação de uma força crescente na direção axial dos instrumentos avaliados, sendo registrada por um software até o deslocamento de 1 mm. A análise dos resultados pelo ANOVA e Tukey revelou que a força máxima para flambar os instrumentos foi maior para os da marca comercial C+File tendo os instrumentos Pathfinder SS apresentado os resultados menos favoráveis. Provavelmente a geometria, que se mostrou completamente distinta para cada grupo de instrumentos, influenciou no comportamento dos mesmos, embora o comprimento não tenha interferido na resistência à flexocompressão.
The aim of this study was to evaluate the buckling resistance of endodontic intruments during the pathfinding of constricted root canals and its lenght influence. Buckling is the elastic deformation of an instrument due to the compressive strenght in its axial direction. The instruments surveyed and tested were: C+File #10, K-File #10 (Maillefer, Switerzland), CC+#10, C-Pilot #10 (VDW, Germany), HI-5 #10 (Miltex, USA) and Pathfinder CS K2 and SS (SybronEndo, USA). Ten instruments from different brands with different lenghts were measured through a optical microscope (Pantec, Panambra, Brazil) aiming to register the diameters, total and useful lenght, taper, helical angles and tip angle, whereas tip details and cross sections were obtained through an electronic microscope MEV (JEOL, JSM-5800). The buckling test was performed at an universal testing machine (EMIC, DL 10.000, Brazil). The maximum load during the elastic deformation was measured by a software while applying increasingly pressure in the axial direction of each instrument till a 1mm deformation. The ANOVA e Tukey test analized the results and revealed that the C+File presented the highest buckling resistance while Pathfinder SS presented the worst results. Different designs might interfere with the results but, in general, the lenght did not have statistical influence.

Nowadays, the most common solution to maintain the teeth of patients that have suffered from a traumatism or a profound caries and have ended with root canal infection is to perform a root canal treatment. For this purpose, Gutta-percha (GP) is one of the main materials used to fill root canals, presenting excellent biocompatibility and good sealing ability. However, GP poor bonding ability to dental tissues has led to high failure rates in endodontic treatments. To address these challenges, many studies have performed research to revise GP. Among the strategies that are being explored as novel endodontic materials, bioactive elements are a promising strategy to improve root canal treatments. For instance, silica based microspheres (SiMS) are an example of bioactive elements that present an active surface and chemical composition that may provide a stronger adhesion to dentin tissue, biocompatibility and the possibility to serve as a possible drug delivery system. In the cases in which the patient presents a more advanced dental pathology, which has led to bone loss surrounding the tooth, the treatment of choice is bone regeneration through a natural bone graft. This is the best option since it presents the same composition as the bone, containing cells with osteogenic potential and growth factors that stimulate cells differentiation into osteoblasts, among others. Nevertheless, this type of grafts present some drawbacks, such as pain, risk of infection, possible disease transmission and limited availability. For this reason, synthetic bone grafts research is one of the main proposals in regenerative medicine. This branch of medicine is based on the development of new biomaterials with the objective of increase the bone healing capacity and, more specific in the dentistry field, to prevent or eliminate bacterial infections at the same time. The present thesis is divided in two parts: i) a treatment focused on the dental system and ii) a treatment focused on the bone system. The first part presents the fabrication of a biomaterial to enhance the GP sealing ability and its bonding capacity with the dental tissue in endodontic treatments; in the second part, two strategies to improve maxillary bone regeneration are presented: the first one through the in vitro study of a low level laser to study its osteogenic effect and cellular proliferation; the second one through the fabrication plus optimization of a biomaterial with a drug sustained release for its potential use as a synthetic bone graft.

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O presente estudo teve como objetivo comparar a qualidade do selamento promovido por 3 cimentos reparadores endodônticos: Ceramicrete, iRoot-BP Plus e BioAggregate, com o ProRoot MTA branco, utilizando o modelo de infiltração de glicose sob pressão. 64 incisivos centrais superiores, recém-extraídos e sem tratamento endodôntico foram selecionados. A instrumentação do canal radicular foi realizada em todos os dentes com brocas Gates-Glidden e limas K-Flexofile (Dentsply Maillefer, Ballaigues Suíça), 1mm aquém do ápice. A patência foraminal foi confirmada a cada instrumento usado. Os dentes tiveram suas coroas removidas padronizando-os em 15mm de comprimento. Foi realizada apicetomia a 3mm do ápice e o preparo da cavidade retrógrada com o auxílio do ultrassom Various 350 (NSKNakanishi Inc., Tóquio, Japão) e da ponta E32D (NSKNakanishi Inc., Tóquio, Japão). As raízes foram distribuídas, randomicamente, em quatro grupos experimentais (n=15): G1Ceramicrete, G2iRoot BP Plus, G3BioAggregate e G4ProRoot MTA branco. Como controle negativo (n=2) foram utilizados dentes hígidos, e como controle positivo (n=2), dentes acessados e com patência confirmada. Os cimentos reparadores foram manipulados seguindo as recomendações do fabricante e inseridos na cavidade retrógrada utilizando a mesma ponta ultrassônica usada no preparo. As amostras foram mantidas na presença de umidade por 72h para o completo endurecimento dos materiais. As raízes foram montadas em um dispositivo de dupla-câmara selada para a infiltração da glicose. Foram utilizados 0,75ml de solução de glicose a 1Mol/L na câmara superior e 0,75ml de água destilada na câmara inferior. Os dispositivos foram conectados a um sistema de distribuição de pressão, que permitiu a infiltração de 32 amostras em uma mesma etapa. A solução de glicose foi forçada apicalmente sob uma pressão de 15psi durante 1 hora. Uma alíquota de 10l foi coletada da câmara inferior para quantificar a glicose infiltrada. A concentração de glicose foi determinada com o auxílio do Kit GlucoseHK (Megazyme, Wicklow, Irlanda) e de um espectrofotômetro de luz visível (Campsec M330, Cambridge, Reino Unido) em um comprimento de onda de 340nm. O teste não-paramétrico Kruskal-Wallis e o teste Dunns foram utilizados na análise estatística. Os resultados encontrados demonstraram que houve diferença significativa entre os grupos experimentais (p=0,0036). O BioAggregate apresentou a maior concentração de glicose-1,85(g/L), seguido do ProRoot MTA-1,2; IRoot BP-0,85 e Ceramicrete-0,75. Não houve diferença entre os três novos cimentos reparadores e o material padrão-ouro (p>0,05). Não houve diferença entre Ceramicrete e iRoot BP Plus (p>0,05), porém estes foram estatisticamente diferentes do BioAggregate (p<0,05). Diante dos resultados obtidos, pode-se concluir que: nenhum dos cimentos testados foi capaz de promover selamento hermético; os três novos cimentos testados não revelaram o mesmo padrão de selamento; os três novos cimentos testados revelaram um padrão de selamento semelhante a do ProRoot MTA branco; e o Ceramicrete e o iRoot BP Plus apresentaram padrão de selamento superior em comparação com o BioAggregate.
The present study sought to compare the sealing ability of three new reparative endodontic cements Ceramicrete, iRoot-BP Plus, BioAggregate and compared to white ProRoot MTA, using the glucose leakage model under pressure. Sixty-four recently extracted maxillary incisors, without previous endodontic treatment, were selected. A crown-down root canal instrumentation was performed using Gates-Glidden burns and Kerr Flexofile (Dentsply Maillefer, Ballaigues Switzerland), 1mm short of the apical foramen (working length). The apical patency was confirmed after the use of each instrument, with a Kerr file #10, 1mm beyond the foramen. The teeth had their crowns removed, leaving roots 15mm in length. After that, apicetomy was carried out at 3mm from the apex. The retrograde preparation was performed using the E32D ultrasonic tip (NSK Nakanishi Inc., Tokyo, Japan). Roots were randomly distributed in four experimental groups (n=15): G1 - Ceramicrete, G2 - iRoot BP Plus, G3 - BioAggregate and G4 - white ProRoot MTA as gold-standard for comparisons. For the negative control group (n=2) teeth with intact crowns were used, and for the positive control (n=2), teeth with access and apical patency. The root-end filling material was manipulated as recommended by the manufacturer and inserted into the retrograde cavity using the same ultrasonic tip. The samples were stored at 100% humidity for three days to allow setting of the material. After that, the roots were mounted in a double-chamber apparatus where 0,75ml of 1Mol/L glucose solution was placed into the superior chamber and 0,75ml of distilled water was placed into the inferior chamber. The devices were connected to a pressure distribution system that was developed to allow the leakage of 32 samples at a single stage. The glucose solution was forced apically under a pressure of 15psi during 1 hour. A sample of 10l was taken from the inferior chamber and the glucose concentration was measured following an enzymatic reaction using the Glucose HK Kit (Megazyme, Wicklow, Ireland) and a spectrophotometer (Campsec M 330, Cambridge, UK) at a wave-length of 340nm. The Kruskal-Wallis and the Dunns test were used for statistical analyses. The results demonstrated that there was significant difference between experimental groups (p=0,0036). BioAggregate displayed the highest glucose concentration - 1.85(g/L), followed by ProRoot MTA - 1.2; iRoot BP Plus - 0.85; Ceramicrete - 0.75. No significant difference was observed between the three new reparative cements and the gold-standard (p>0.05). There was no difference between Ceramicrete and iRoot BP Plus (p>0.05), however both materials were significantly different fromBioAggregate (p<0.05). Considering the results, it can be concluded that none of the tested cements was able to prevent glucose leakage, the 3 new tested cements do not presented a similar quality of sealing, and the three new tested cements presented a similar sealing pattern of ProRoot MTA and both Ceramicrete and iRoot BP Plus presented better quality of sealing than BioAggregate.