Submitted by Renan Dal Fabbro (renandalfabro@gmail.com) on 2017-08-21T13:17:33Z No. of bitstreams: 1 Mestrado Renan.pdf: 1996961 bytes, checksum: 56e2ace3a1a9fd59c575055bd82cb0d3 (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-08-23T19:21:27Z (GMT) No. of bitstreams: 1 fabbro_rd_me_araca.pdf: 1996961 bytes, checksum: 56e2ace3a1a9fd59c575055bd82cb0d3 (MD5) / Made available in DSpace on 2017-08-23T19:21:27Z (GMT). No. of bitstreams: 1 fabbro_rd_me_araca.pdf: 1996961 bytes, checksum: 56e2ace3a1a9fd59c575055bd82cb0d3 (MD5) Previous issue date: 2017-07-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Objetivo: analisar o efeito do consumo crônico de álcool no desenvolvimento da lesão periapical. Material e métodos: Trinta e dois ratos foram divididos em 4 grupos: Controle (C): sem periodontite apical (PA) e dieta não alcoólica (DNA); (AL): sem PA e dieta alcoólica (DA); (AP): com PA e DNA; (AP+AL): com PA e DA. Solução alcoólica à 20% foi fornecida aos grupos AL e AP+AL como única fonte de hidratação por todo experimento. A PA foi induzida nos primeiros molares inferiores esquerdos ao final da 4a semana de administração da dieta alcoólica. Alterações de peso, e quantidade de alimentos sólidos e líquidos foram tabulados ao longo das 8 semanas. Ao final deste período, os animais foram eutanaziados e as mandíbulas removidas para análise da densidade óssea seguida do processamento histológico para histomorfometria, bem como análise por imunohistoquímica da expressão das proteínas RANKL, OPG, TRAP, HIF-1α e ALP. As comparações múltiplas dos resultados foram realizadas por análise de variância seguida pelo teste de Tukey. Para dados não paramétricos foi utilizado o teste de Mann-Whitney nas comparações CvsAL e APvsAP+AL. O nível de significância utilizado foi de p<0,05. Resultados: animais que receberam a dieta alcoólica tiveram um ganho de peso inferior aos dos outros grupos p<0,05. A área da região periapical não foi influenciada pela administração da solução alcoólica, entretanto, o infiltrado inflamatório foi mais intenso em AP+AL comparado à AP p<0,05. Análise radiográfica mostrou diferença apenas entre os grupos com e sem PA. O grupo AP+AL mostrou os maiores valores para indicadores de osteoclastogênese TRAP, HIF-1α e RANKL p<0,05. Conclusão: A dieta alcoólica exerceu efeito significativo na severidade da periodontite apical, exacerbando a resposta inflamatória e a osteoclastogênese. / Aim: evaluate the effect of chronic alcohol consumption on the periapical lesion. Material and methods: Thirty-two rats were divided into 4 groups: Control (C): without apical periodontitis (AP) and non-alcoholic diet (NDA); (AL): without AP and alcoholic diet (AD); (AP): with AP and NDA; (AP + AL): with AP and AD. Alcoholic solution at 20% was given to the AL and AP+AL groups as the sole source of hydration throughout the experiment. AP was induced in the lower left first molars at the end of the 4th week. Changes in weight, and amount of solid and liquid foods were recorded over 8 weeks. At the end of this period, the animals were euthanized and the jaws removed for of x-ray bone density analysis followed by histological processing for histomorphometry, as well as immunohistochemical analysis for RANKL, OPG, TRAP, HIF-1α and alkaline phosphatase. Multiple comparisons of results were performed by analysis of variance followed by the Tukey test. For non-parametric data the Mann-Whitney test was used in the comparisons CvsAL and APvsAP+AL. The level of significance was set at p <0.05. Results: animals that received alcoholic diet had a weight gain lower than the other groups p <0.05. The periapical region area was not influenced by the administration of the alcohol solution, however, the inflammatory infiltrate was higher in AP+AL compared to the AP p <0.05. Radiographic analysis showed difference only in the comparisons between the groups with and without apical periodontitis. The AP+AL group showed the highest values for osteoclastogenesis markers TRAP, HIF-1α and RANKL p <0.05. Conclusion: Alcoholic diet had a significant effect on the severity of apical periodontitis, exacerbating the inflammatory response and osteoclastogenesis.

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-08-16T15:02:36Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Etienny S. Arruda.pdf: 1036150 bytes, checksum: da9374202f42a247cfc89a0badd0cee2 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-08-16T15:04:58Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Etienny S. Arruda.pdf: 1036150 bytes, checksum: da9374202f42a247cfc89a0badd0cee2 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-08-16T15:05:24Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Etienny S. Arruda.pdf: 1036150 bytes, checksum: da9374202f42a247cfc89a0badd0cee2 (MD5) / Made available in DSpace on 2017-08-16T15:05:24Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Etienny S. Arruda.pdf: 1036150 bytes, checksum: da9374202f42a247cfc89a0badd0cee2 (MD5) Previous issue date: 2017-04-12 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / The purpose of this study was to evaluate a protocol for endodontic retreatment, using Protaper Next instruments, to evaluate the occurrence of apical transportation using CT. To perform the experiment, 40 mandibular molars were selected, with mesial root canal curvature between 30° and canal curvature radius less than or equal to 10 mm. Size 10 K-type instruments were used to determine the presence of independent foramen. In order to standardize the samples, the crowns were partially sectioned in 16 mm and all the specimens were inserted in resin blocks, to standardize the tomographies in the same position before, during and after instrumentation and retreatment. They were also submitted to the same instrumentation and obturation process, and were then randomly separated (n = 10) into four experimental groups: PTU group, in which the instrument used to remove gutta-percha was Protaper F2 (25.08); Group R25 and Group X2 where the Reciproc - R25 (25.08) and Protaper Next - X2 (25.06) instruments were used for the same purpose, respectively; And Group X3, where the X2 instruments were used sequentially for the removal of gutta-percha and X3 (30.07) for channel remodeling, both belonging to the Protaper Next system. Apical deviation was assessed by applying formulas to values obtained before and after instrumentation, and with the data obtained it was also possible to analyze centering ratio and percentual area increase. Data were subjected to the Kruskal-Wallis Test and the Dunn Multiple Comparisons Test. The results of the apical deviation presented no significant difference between the experimental groups (p <0.05). The methodology and the results lead to the conclusion that the experimental groups did not produce a statistically significant difference in apical deviation. / O objetivo do presente estudo foi avaliar a viabilidade de um protocolo de retratamento endodôntico, utilizando instrumentos Protaper Next, avaliando a ocorrência de transporte apical em raízes mesiais curvas de molares inferiores. Foram selecionados 40 molares inferiores com grau de curvatura da raiz mesial de aproximadamente 30° e raio de curvatura menor ou igual a 10 mm. Com o auxílio de instrumentos tipo K #10, avaliou-se a presença de forames independentes. Com o objetivo de padronizar o as amostras, as coroas foram parcialmente seccionadas em 16 mm e todos os corpos de prova foram inseridos em blocos de resina, para padronização das tomografias na mesma posição antes, durante e após a instrumentação e retratamento. Também foram submetidas ao mesmo processo de instrumentação e obturação, e só depois foram separadas aleatoriamente (n=10) em quatro grupos experimentais: Grupo Protaper Universal (PTU), no qual o instrumento utilizado para a remoção da gutta-percha era a Protaper F2 – 25.08; Grupo Reciproc e Grupo Protaper Next X2 onde para a mesma finalidade eram empregados os instrumentos Reciproc R25 – 25.08 e Protaper Next X2 – 25.06, respectivamente; e o Grupo Protaper Next X3, onde eram utilizados sequencialmente os instrumentos X2 para a remoção da gutta-percha e o X3 (30.07) para remodelação do canal, ambos pertencentes ao sistema Protaper Next. A análise do desvio apical se deu pela aplicação de fórmulas aos valores obtidos antes e após a instrumentação e com os dados obtidos também foi possível analisar o índice de centralização dos intrumentos bem como o aumento percentual da área proporcionado por eles. Os dados obtidos foram submetidos a testes de Kruskall-Wallis e teste de Múltiplas Comparações de Dunn. Os resultados do desvio apical não mostraram diferenças significantes entre os grupos avaliados (p < 0,05). Com base na metodologia empregada e nos resultados obtidos, concluiu-se que não houve, entre os grupos experimentais, diferença significante em relação à produção de desvio apical.

After cleaning and shaping of the root canal the final objective of the endodontic procedure is to obtain a three-dimensional obturation of the root canal space with a fluid-tight seal at the apical foramen. The objective of this in vitro study was to evaluate four different obturation techniques in respect of: • the radiographic quality of root canal obturation, • apical leakage and • the potential of these techniques to obdurate lateral canals One hundred and sixty canals were prepared by using RaCe nickel titanium rotary files to a size 30 with 6% taper. During preparation irrigation was done with TopClear Solution (17% EDTA and 0.2% cetremide) and ChlorXTRA (6% sodium hypochlorite). The canals were divided in four groups of forty canals each and were obturated using the Hybrid Root SEAL technique, the EndoREZ technique, the System B/Obtura technique and the Thermafil technique. The Radiographic Quality of Root Canal Obturation: Digital radiographs were taken of the four groups of obturated canals from a buccolingual and a mesiodistal direction. The quality of obturation was determined for the coronal and apical halves of each canal and scored according to radiographic appearances. The data was tabulated and statistically analyzed using the Mann- Whitney U test. The Hybrid Root SEAL technique demonstrated a statistically significant higher number of radiographic defects in the coronal aspects of the root canals when compared to the System B/Obtura and Thermafil techniques (p<0.05). There was no statistically significant difference between the radiographic defects in the coronal aspects of the root canals between Hybrid Root SEAL and EndoREZ techniques (p>0.05). The Hybrid Root SEAL technique demonstrated a statistically significantly higher number of radiographic defects in the apical aspects of the root canals compared to all the other groups (p<0.05). Apical Leakage: Twenty obturated canals of each of the four groups were processed for evaluation of apical leakage. The root surfaces were coated with nail varnish and sticky wax, leaving 4.0 mm around the apical foramen exposed. Specimens were immersed in 2% methylene blue dye for 48 hours, rinsed in distilled water and embedded in clear acrylic resin. Specimens were sectioned horizontally in 1 mm increments and the extent of dye penetration was measured to the nearest millimeter using a stereomicroscope. The data was tabulated and statistically analyzed using the Man-Whitney U test. The specimens that were obturated with the EndoREZ technique demonstrated the least apical leakage compared to all the other groups tested in this study. However, there was only a statistically significant difference when the EndoREZ technique was compared to the Hybrid Root SEAL and System B/Obtura techniques (p<0.05). The specimens that were obturated with the System B/Obtura technique demonstrated the most apical leakage compared to all the other groups tested in this study. However, there was only a statistically significant difference when the System B/Obtura technique was compared to the EndoREZ and Thermafil techniques (p<0.05). The Potential to Seal Lateral Canals: Twenty obturated canals of each of the four groups were processed for evaluation of the potential to seal lateral canals. The specimens were subjected to a clearing technique and a morphological analysis was performed using a stereomicroscope. Lateral canals were counted and graded within the coronal, middle and apical thirds of the roots. The data was tabulated and statistically analyzed using the Man-Whitney U test. The Thermafil technique demonstrated the greatest number of filled lateral canals. However, there was no statistically significant difference between the Thermafil technique and all the other techniques (p<0.05). / Dissertation (MSc)--University of Pretoria, 2009. / Odontology / unrestricted

Orientador: Marcia Carneiro Valera / Coorientador: Carlos Henrique Ribeiro Camargo / Banca: Cláudio Antonio Talge Carvalho / Banca: Marco Antônio Húngaro Duarte / Resumo: Os objetivos deste estudo foram: Artigo 1 - Analisar a extrusão apical de hipoclorito de sódio (NaOCl), debris e sua citotoxicidade após o preparo dos canais radiculares utilizando NaOCl líquido ou gel. Artigo 2- avaliar a dissolução de matéria orgânica do NaOCl líquido e gel, e a limpeza das paredes dentinárias após a instrumentação; Métodos: Artigo 1 - A avaliação da extrusão apical de NaOCl e debris foi feita pela espectrofotometria do conteúdo extruído após o preparo biomecânico. A citotoxicidade foi avaliada pela resposta de culturas celulares de fibroblastos de ligamento periodontal (PDFL) frente as soluções irrigadoras extruídas, pelo teste XTT para análise da viabilidade celular. Para isso, oitenta dentes foram instrumentados com limas Reciproc #25 e #40 (VDW Munique, Alemanha) e utilizado NaOCl gel e líquido ativados por ultrassom. Os dados foram analisados estatisticamente pelo teste de ANOVA e as diferenças estatísticas pelo teste de Tukey e Dunn (p<0,05). Artigo 2 - A dissolução de matéria orgânica foi realizada usando cubos de carne com tamanho e peso determinado, os quais foram deixados em contato com 1 mL das amostras dos seguintes grupos: NaOCl gel 3% (ChlorCid V); NaOCl gel 3%(VIM); NaOCl líquido 2,5%; NaOCl líquido 5,25%; Solução fisiológica estéril (SF) (controle) por um período de 3 min, os fragmentos foram removidos e pesados novamente para quantificar a matéria orgânica não dissolvida. A comprovação da limpeza das paredes dos canais foi avaliada através ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objectives of this study were: Article 1 - Analyze the apical sodium hypochlorite (NaOCl) extrusion, debris and it's cytotoxicity after the root canals preparation using liquid or gel NaOCl. Article 2 - Evaluate the tissue dissolution of NaOCl liquid and gel, and it's cleaning efficiency of dentin walls after instrumentation; Methods: Article 1 - The evaluation of the apical extrusion of NaOCl and debris was done by the spectrophotometry of the extruded contents after the biomechanical preparation. Cytotoxicity was evaluated by the cell cultures response of periodontal ligament fibroblasts (PDFL) against extruded irrigation solutions by the XTT test for cell viability analysis. For this, eight teeth were instrumented with Reciproc # 25 and # 40 files (VDW Munich, Germany) and used NaOCl gel and liquid activated by ultrasound. Data were analyzed statistically by the ANOVA test and the statistical differences by the Tukey and Dunn test (p <0.05). Article 2 - The dissolution of organic matter was carried out using meat cubes of determined size and weight, which were left in contact with 1 mL of samples from the following groups: NaOCl gel 3% (ChlorCid V); NaOCL gel 3% (VIM); NaOCl liquid 2.5%; NaOCl liquid 5.25%; Sterile physiological solution (SP) (control) for a period of 3 min, the fragments were removed and weighed again to quantify the undissolved organic matter. The verification of the cleansing of the canal walls was evaluated through the SEM and the stereomicroscopy ... (Complete abstract click electronic access below) / Mestre

La paroi des cellules végétales subit des modifications afin de s'assouplir ou de se rigidifier selon les besoins de la plante. Cette paroi est une structure complexe, composée de cellulose, d'hémicellulose et de pectines. Les modifications subies par les pectines au cours de l'élongation cellulaire sont encore assez peu caractérisées. Dans ce contexte, le but de ce projet est d'étudier le rôle de deux polygalacturonases (PG) dans le développement racinaire de la plante modèle A. thaliana. Les PG sont des enzymes de dégradation des homogalacturonanes (HG), le composant pectique majoritaire de la paroi primaire. Notrehypothèse est que les PG dégradent partiellement les HG des parois longitudinales des cellules racinaires en élongation. Cette dégradation engendrerait un assouplissement pariétal localisé, permettant la croissance anisotropique des cellules. Nos résultats indiquent que les gènes des deux PG étudiées, nommés PG ROOT APICAL MERISTEM (PG RAM) et PG ROOT (PG R) sontexprimés de façon complémentaire dans la racine, l'un dans le méristème racinaire (PG RAM), et l'autre dans la zone d'élongation et de différenciation (PG R). De plus, la sur-expression de la protéine PG R entraine une augmentation de l’élongation des hypocotyles étiolés, ainsi qu'une augmentation de la densité de racines latérales par rapport au sauvage, démontrant son rôle dans le développement racinaire et dans l'allongement cellulaire. Enfin, nous avons démontré que l'expression des gènes de ces PG était contrôlée de façon différentielle par les facteurs de transcription de la famille PLETHORA (PLT). / Plant cell wall structure is modified to control its stiffness or flexibility according to plant’s requirements. The cell wall is a complex structure, composed of cellulose, hemicelluloses and pectins. Pectin modifications during cellular elongation are not very well characterized. In this context, the aim of this project is to study the roles of two polygalacturonases (PG) in the root development on the model plant A. thaliana. PG are homogalacturonans (HG) degradation enzymes, HG being the major pectic component of the primary cell wall. This degradation would lead to a local parietal relaxation, allowing anisotropic growth of the cells. Our results show that the two studied PG, named PG ROOT APICAL MERISTEM (PG RAM) and PG ROOT (PG R), are expressed in complementary areas of the root, either in the root apical meristem (PG RAM) or in the elongated and differenciated root tissues (PG R). Furthermore, the over-expression of PG R results in longer etiolated hypocotyls and increases root density when compared to wild-type, demonstrating its function in root development and in cell elongation. Finally, we demonstrated that expression of these two PG genes is under the control of PLETHORA (PLT) family transcription factors, by differentially ways

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京都大学 / 新制・課程博士 / 博士(地球環境学) / 甲第24059号 / 地環博第222号 / 新制||地環||42(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)准教授 岡田 直紀, 教授 柴田 昌三, 教授 德地 直子 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DGAM

Este estudo clínico prospectivo avaliou a taxa de sucesso do tratamento endodôntico utilizando um protocolo antimicrobiano definido. Trinta e cinco dentes unirradiculares com periodontite apical primária foram submetidos ao tratamento endodôntico. O preparo químico-cirúrgico foi realizado com instrumentos reciprocantes, utilizando NaOCl 2,5%, seguidos de ativação com o instrumento XP-endo Finisher e irrigação ultrassônica passiva como procedimentos complementares de desinfecção (PCD) na 1a consulta. Os canais radiculares foram preenchidos com pasta de hidróxido de cálcio por 14 dias e obturados após reinstrumentação dos canais radiculares na 2a consulta. Coletas microbiológicas realizadas no momento da obturação, analisadas por qPCR baseada em 16S rDNA, foram correlacionadas com o prognóstico do tratamento. Vinte e sete casos retornaram para acompanhamento, aproximadamente 12 meses após o tratamento. O sucesso do tratamento endodôntico foi analisado baseado em critérios clínicos, radiográficos e tomográficos. A análise das imagens foi realizada por 2 avaliadores treinados, com valor de Kappa igual a 0,74 e 0,6 para tomografia e radiografia, respectivamente. A tomografia computadorizada de feixe cônico (TCFC) apresentou maior especificidade (37%) pós tratamento quando comparada com a radiografia periapical (59,3%) (p = 0,03). Porém, quando o sucesso do tratamento foi analisado pela ausência ou redução da lesão periapical, ambos os métodos apresentaram o mesmo índice de sucesso (89%). A variação do volume das lesões periapicais foi significativa 1 ano após o tratamento (p < 0.0001). Dos 22 casos que possuíam dados microbiológicos, 32% apresentaram reações qPCR positivas no momento da obturação. A presença de baixos níveis de DNA bacteriano no momento da obturação dos canais radiculares não exerceu influência no prognóstico do tratamento. Concluiu-se que a taxa de sucesso do tratamento endodôntico utilizando PCD foi elevada, provavelmente devido à drástica redução bacteriana promovida pelo protocolo estudado. / This prospective clinical trial evaluated the success rate of endodontic treatments using a defined antimicrobial protocol. Thirty-five unirradicular teeth with primary apical periodontitis were submitted to endodontic treatment. The chemicalsurgical preparation was performed with reciprocating instruments, using NaOCl 2.5%, followed by activation with XP-endo Finisher and passive ultrasonic irrigation as complementary procedures in the 1st session. The root canals were dressed with calcium hydroxide paste for 14 days and root filing were performed after re-instrumentation. Microbiological samples were performed at the time of root filling, analyzed by qPCR based on 16S rDNA, and correlated with the treatment outcome. Twenty-seven cases returned for follow-up, approximately 12 months after treatment. The success of endodontic treatment was analyzed based on clinical, radiographic and tomographic criteria. The images analysis was performed by 2 trained evaluators with a Kappa value of 0.74 and 0.6 for tomography and radiography, respectively. Cone-beam computed tomography (CBCT) showed higher rate of specificity (37%) post treatment when compared to periapical radiography (59.3%) (p = 0.03). However, when the success was analyzed by absence or reduction of the periapical lesion, both methods had similar success rate (89%). The periapical lesions volume was significantly reduced 1 year after treatment (p <0.0001). From 22 cases with microbiological data, 32% had positive qPCR reactions at the time of root filling. The presence of low levels of bacterial DNA at the moment of root filling had no influence on the treatment outcome. It was concluded that the success rate of endodontic treatment using complementary disinfection procedures was high, probably due to the drastic bacterial reduction promoted by the studied protocol.

O principal objetivo do tratamento endodôntico em dentes com infecções primárias é a cura da periodontite apical, o que ocorre geralmente após a máxima redução de micro-organismos do canal radicular. Métodos microbiológicos moleculares são os métodos de escolha para avaliar a redução de micro-organismos após o tratamento endodôntico por serem mais sensíveis, específicos e precisos do que os métodos baseados em cultura bacteriológica. Entretanto, poucos estudos clínicos avaliaram a eficácia antimicrobiana do tratamento endodôntico por métodos moleculares. Além disso, até o presente momento, não há nenhum estudo correlacionando esses dados com o sucesso do tratamento endodôntico. Portanto, os objetivos do presente estudo foram: (a) avaliar in vivo, por métodos moleculares quantitativos, a concentração de bactérias nos canais radiculares e sua, correlação com aspectos clínicos e radiográficos; (b) correlacionar a redução bacteriana após o tratamento endodôntico com reparo apical após controle radiográfico e tomográfico. Trinta e quatro pacientes portadores de dentes com necrose pulpar e periodontite apical foram selecionados para o estudo. O protocolo de antissepsia consistiu em realizar o Preparo Químico-Cirúrgico (PQC) com sistema Reciproc e NaOCl 2,5%; irrigação final com EDTA-T 17%; e medicação intracanal com pasta de hidróxido de cálcio por 14 dias antes da obturação dos canais radiculares. Foram realizadas coletas microbiológicas dos canais radiculares no início do tratamento e na segunda sessão, após a remoção da medicação intracanal antes da obturação. As amostras microbiológicas foram analisadas por Reação em Cadeia da Polimerase quantitativa (qPCR) para detecção e quantificação de bactérias utilizando iniciadores universais para o domínio Bactéria. Para análise do sucesso do tratamento endodôntico, foram analisados aspectos clínicos, radiográficos e tomográficos após um período mínimo de controle de 1 ano. Os casos foram classificados em 4 categorias: ausência de rarefação óssea periapical, redução ou aumento e incerto. Bactérias foram observadas em 100% das amostras iniciais coletadas, com concentrações medianas de 1,68 x 106 cópias de DNA. A análise estatística de regressão logística não apresentou correlação entre concentrações de DNA bacteriano com dados clínicos. Após o tratamento endodôntico, as medianas das concentrações de bactérias foram de 8.72 x 102, os resultados mostraram que houve diminuição significativa na concentração de DNA bacteriano (p<0,05), correspondendo a porcentagem de redução de 99.98% nos canais radiculares após os procedimentos de antissepsia. Retornaram para o controle, 20 dos 34 pacientes (58,82%), entre 13 a 22 meses após o tratamento endodôntico. Dois dentes foram extraídos, restando um total de 18 dentes para análise clínica e radiográfica. O sucesso classificado por ausência ou redução da rarefação óssea na radiografia periapical foi observada em 16 dos 18 dentes (88,83%). Dos 2 casos de insucesso radiográfico, um apresentou elevada quantidade de bactérias (>104) persistentes após os procedimentos de antissepsia e um caso apresentou obturação deficiente. Entretanto, a análise estatística de regressão logística não identificou nenhum fator específico associado ao insucesso endodôntico. A análise tomográfica foi realizada em 12 dos 18 pacientes. Os achados tomográficos confirmaram ausência/ redução da rarefação periapical verificada na radiografia, com exceção de um caso onde não houve redução da área da rarefação. Conclui-se que dentes com necrose pulpar e periodontite apical apresentam uma elevada concentração de bactérias no sistema de canais radiculares. O tratamento endodôntico foi eficaz em reduzir significativamente a quantidade de bactérias dos canais radiculares e promover uma elevada taxa de sucesso endodôntico. / The objectives of the endodontic treatment of teeth with primary infections is the healing of apical periodontitis, which usually occurs after the maximum reduction of micro-organisms in the root canal. Molecular methods are the methods of choice for assessing the reduction of micro-organisms after endodontic treatment to be more sensitive, specific and accurate than methods based on bacteriological culture. The objectives of this study were to evaluate in vivo by molecular methods, the concentration of bacteria in root canals and correlation of bacterial reduction after endodontic treatment with apical repair after radiographic control and CBCT. Thirty four teeth with apical periodontitis, with radiographic evidence of periapical were selected for this study. The root canal preparation of all the teeth was carried out with reciprocating files and 2.5% NaOCl during preparation; and 17% EDTA for smear layer removal. The root canals were medicated with calcium hydroxide for 14 days. Microbiological sampling were performed before the preparation and after intracanal medication. The samples were analyzed by real time PCR, for the detection and quantification of bacteria,. Bacteria were observed in 100% of the initial samples. . Bacteria were observed in 100% of the initial samples, with median concentrations of 1.68 x 106 copies of the DNA. After endodontic treatment, the median bacterial concentrations were 8.72 x 102, the results showed a significant decrease in the concentration of bacterial DNA (p <0.05), corresponding to 99.98% reduction in the percentage of root canals after procedures of antisepsis. 13 to 19 months after treatment, the teeth were examined by using periapical radiography (PA) and cone-beam computed tomography (CBCT). Area and volume of the periapical lesions were measured, and the outcome was presented in 4 categories: absence, reduction or enlargement of the radiolucency, or uncertain. Lesions were classified as reduced or enlarged when the change in size of the radiolucency was 20% or more. The recall rate was 58,82%, and 18 teeth were analyzed. Success classified by the absence or reduction of bone thinning in periapical radiography was observed in 16 of the 18 teeth (88.83%). CT findings confirmed the absence / reduction of periapical rarefaction observed on radiographs, except for one case. Conclude that teeth with pulp necrosis and apical periodontitis have a high concentration of bacteria in the root canal system. The endodontic treatment was effective in significantly reducing the amount of bacteria from root canals and to promote a high rate of success endodontic.