The aim of this study was to determine if a buccal curvature in the palatal roots of maxillary molars affected the clinician’s ability to accurately determine working length. Twenty-seven extracted, human maxillary molars were sorted by palatal root curvatures as J- and C-type and the angle of curvature was determined. Straight-line access was made and a #20 file was placed into the canal until the tip was visible at the apical foramen then withdrawn. The file, tooth and calibration wire were radiographed on one image using the RVG. Actual (file) and radiographic (tooth) lengths were determined using the RVG ruler. Radiographic length appeared shorter on average than the actual length. Canal curvatures larger than 25 degrees had differences greater than 0.5mm. This represents a statistically significant difference between the actual and radiographic lengths as the degree of curvature increases. There was no significant difference between the J- and C- types.

This study determined if the cleaning efficiency of NiTi rotary files in an endodontic electric handpiece using a no torque control setting was superior to that obtained when using the torque control feature. Fifty extracted human anterior teeth with straight canals were divided into two groups of 20 and two control groups of 5. Canals were instrumented with GT and .04 Profile NiTi files until a size 35 advanced to working length. Samples were sectioned, the apical 6 mm of the canal was photographed (x20) and projected onto a 3 x 4 foot grid with squares measuring 0.5 inches each. Total debris was the percentage of the number of squares containing debris versus the total number of squares. Results showed that the teeth in the torque controlled group showed an average of 24.99% debris vs. 15.55% for the teeth in the no torque group. The difference was not statistically significant.

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.

Orientador: Caio Cezar Randi Ferraz / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-10T15:20:35Z (GMT). No. of bitstreams: 1 Cintra_LucianoTavaresAngelo_D.pdf: 6050178 bytes, checksum: e2ba3143f76becede13f0d5a4bcd67ac (MD5) Previous issue date: 2008 / Resumo: O objetivo do presente estudo foi observar por meio da microscopia óptica de luz, o efeito de diferentes substâncias químicas auxiliares empregadas durante o preparo químico-mecânico, no processo de reparo periapical, além do efeito do uso de uma medicação intracanal entre as sessões. Para tanto, 110 raízes de 5 cães adultos jovens, com polpa necrótica e associadas à lesão periapical crônica, foram instrumentadas endodonticamente através de técnica padronizada, variando-se as substâncias químicas auxiliares: soro fisiológico; base gel natrosol; hipoclorito de sódio 2,5% (NaOCl); clorexidina gel 2% (CG); clorexidina líquida 2% (CL). Concluído o preparo químico-mecânico, 55 raízes foram obturadas imediatamente (sessão única) e 55 raízes receberam um curativo de hidróxido de cálcio [Ca(O H)2], iodofórmio e soro fisiológico. Os grupos de duas sessões foram obturados após 14 dias da colocação da medicação intracanal.c Após um período de 270 dias da obturação dos canais radiculares, os animais foram sacrificados e as peças processadas laboratorialmente. Os cortes teciduais foram corados em H.E. ou pela coloração de Brown e Breen e receberam escores levando-se em consideração critérios de análise microscópica quanto às características do infiltrado inflamatório e condições de reparo periapical, previamente estabelecidos. Os valores obtidos foram submetidos ao teste de Kruskal-Wallis e Dunn, com nível de significância de 5%. Os resultados demonstraram que o uso da CG e NaOCl como substâncias químicas auxiliares, associados ou não ao uso de medicação intracanal, proporcionaram resultados semelhantes e superiores aos demais grupos, tanto em intensidade do infiltrado inflamatório quanto às condições do reparo periapical / Abstract: The goal of the present study was to observe through optic microscopy, the effect of different auxiliary chemical substances, used during the chemomechanical preparation, and of an intracanal dressing in the periapical healing process. Hundred-ten dental roots from 5 young adult dogs, with necrotic pulp associated to a chronic periapical lesion were endodontically instrumented with a standardized technique, just varying the auxiliary chemical substances: sterile saline (negative control 1); gel base natrosol (negative control 2); 2,5% Sodium hypochlorite (NaOCl); 2% chlorhexidine gel (CG); 2% chlorhexidine liquid (CL). After the chemo-mechanical preparation, 55 roots were immediately filled (singlevisit) and 55 roots received a calcium hydroxide dressing [Ca (OH)2]. The specimens from the multiple-visit groups were filled after 14 days. Past 270 days from the filling, the animals were sacrificed and the specimens were histologically processed. The slides were stained on H.E. or Brown and Breen techniques and were microscopically assessed using previously established criteria. The data were submitted to the Kruskal-Wallis and Dunn, with 5% as significance level. The results demonstrated that the use of CG and NaOCl as auxiliary chemical substances, associated or not to intracanal medication, provided similar results, either in inflammatory infiltrated intensity or in periapical healing / Doutorado / Endodontia / Doutor em Clínica Odontológica

Orientadores: Rogerio de Castilho Jacinto, Brenda Paula Figueiredo de Almeida Gomes / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T07:58:55Z (GMT). No. of bitstreams: 1 Signoretti_FernandaGrazielaCorrea_M.pdf: 1459637 bytes, checksum: 7020ff35d9c6dbacb3cdbc7ad01ef8bd (MD5) Previous issue date: 2009 / Resumo: O presente estudo avaliou a influência da clorexidina 2% gel (CLX) sobre as propriedades químicas como pH e liberação de íons cálcio do hidróxido de cálcio, e sobre a capacidade de redução de endotoxinas desta medicação intracanal. A liberação do cálcio do Ca(OH)2 + soro ou associado a CLX foi verificada pela espectrofotometria por absorção atômica e o pH através do emprego de um peagâmetro. As mensurações foram realizadas nos períodos experimentais de 24 horas, 7, 15 e 30 dias. Para a quantificação de endotoxinas foram utilizados dentes humanos, previamente preparados, contaminados, preenchidos com as medicações. Os medicamentos foram inseridos dentro dos canais de 30 dentes (GI Ca(OH)2 + soro, GII Ca(OH)2 + CLX, GIII CLX), e após permanecerem por 14 dias foram removidos com irrigação abundante. Este lavado foi submetido à quantificação da endotoxina remanescente através do teste cromogênico quantitativo QLC-1000. Análise estatística foi realizada com os testes ANOVA e Tuckey (p<0.05). Os grupos do Ca(OH)2 associado ou não à CLX não diferiram significativamente no período de 24 horas, 7 e 30 dias em relação à liberação de cálcio. Entretanto no período de 15 dias o Ca(OH)2 + soro fisiológico liberou menos cálcio do que quando estava associado à clorexidina 2% gel. Nestes mesmos grupos ocorreu aumento significativo de 24 horas para 7 dias. Entretanto no período de 15 dias houve uma queda do Ca(OH)2+ soro. Com relação ao pH, os grupos do Ca(OH)2 associado ou não à CLX não apresentaram diferença significativa estatisticamente entre si nos intervalos testados, mantendo um pH alcalino (p>0.05). Os maiores valores de pH foram observados após 30 dias para o Ca(OH)2 + soro. Os valores mais baixos de pH foram apresentados pela clorexidina 2% gel quando testada sozinha, em todos os períodos. Um aumento significativo no pH foi observado no intervalo de 24 horas e 7 dias, tanto para o Ca(OH)2 + soro quanto para Ca(OH)2 + CLX. A maior redução de endotoxinas foi observada no grupo da clorexidina 2% gel (91,63%), seguida de sua associação com o Ca(OH)2 (88,76%) e depois o Ca(OH)2 + soro fisiológico (82,13%). Não houve diferença estatística entre a clorexidina 2% gel e sua associação com o hidróxido de cálcio, quanto à redução da quantidade de endotoxinas dentro do canal radicular. Concluiu-se que a clorexidina 2% gel não interferiu no pH e liberação de íons cálcio do hidróxido de cálcio quando em associação com este. Além disso, melhorou a capacidade do hidróxido de cálcio em reduzir o conteúdo de endotoxinas dos canais radiculares in vitro. / Abstract: The aim of the present study was to evaluate the influence of 2% chlorhexidine gel (CHX) on chemical properties of calcium hydroxide and on its ability of reducing endotoxic content of root canals when used as intracanal medicament. The amount of calcium released from the pastes was assessed by atomic absorbance spectophotometry and the pH was verified in pHmeter. The tested periods were 24 hours and 7, 15 and 30 days. For the endotoxin quantification assay, single rooted teeth were previously inoculated with endotoxins and then with intracanal medication. The medicaments were placed inside the root canal of 30 teeth, (GI - Ca(OH)2 + 0.9% saline solution, GII - Ca(OH)2 + CHX and GIII - CHX), and were removed after 14 days, with copiously irrigation. The removed solution was submitted to the chromogenic quantitative endotoxin test QCL-1000 Statistical analysis was performed with ANOVA and Tuckey Test (p<0.05). For calcium release analysis there was no statistical difference among the groups with Ca(OH)2 associated or not with CHX in the periods of 24 hours, 7 days and 30 days. However, after 15 days, lower values were observed for Ca(OH)2+ saline solution. In the groups that contained calcium hydroxide associated or not with CHX, an increase in ion release was observed from 24h to 7 days. However there was a decrease in the period of 15 days for the Ca(OH)2+ saline solution. An alkaline pH was observed in all groups that contained calcium hydroxide (p>0.05). The highest pH values were observed after 30 days for the association between Ca(OH)2 + saline solution. The lowest values of pH were observed for 2% chlorhexidine gel, in all periods. A higher increase of pH was stated between 24 h and 7 days for Ca(OH)2+ saline solution and Ca(OH)2+ CHX, and remained unaltered until the end of the experiment for both pastes. A higher reduction in the endotoxin content was observed in the CHX group (91.63%), followed by Ca(OH)2+ CHX (88,76%) and Ca(OH)2 + saline solution (82.13%). There were no statistical difference between 2% chlorhexidine gel and its association with calcium hydroxide over the endotoxin content reduction inside the root canal. According to the results, it can be concluded that 2% chlorhexidine gel did not interfere in the chemical properties of calcium hydroxide. Moreover, chlorhexidine was also able to improve calcium hydroxide properties for reducing the endotoxic content of root canals in vitro. / Mestrado / Endodontia / Mestre em Clínica Odontológica

Orientador: Francisco Jose Souza Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-14T06:25:48Z (GMT). No. of bitstreams: 1 Berger_CarlosRoberto_D.pdf: 7347210 bytes, checksum: 564e46ae66009c800a919cd31561e9b8 (MD5) Previous issue date: 2009 / Resumo: Esse estudo avaliou a composição química da parte inorgânica e a presença de formaldeído em cimentos endodônticos indicados para obturação do sistema de canais radiculares. Sete cimentos endodônticos foram escolhidos: quatro a base de óxido de zinco e eugenol (Targer Canal Sealer - Konne; Endo Fill - Dentsply; Endométhasone N - Septodont e; Pulp Canal Sealer EWT - Kerr); dois a base de agregado trióxido mineral (MTA) (Endo CPM Sealer - EGEO Dental e Obtura - Ângelus) e; um a base de resina/hidróxido de cálcio (Sealer 26, Dentsply). Todos os materiais foram manipulados de acordo com as recomendações de cada um dos fabricantes e inseridos em um porta-amostra de 5 cm de diâmetro e 0,5 cm de altura. Após tomar presa foram analisados através de dois métodos: Difratometria de Raios X, para a análise da parte inorgânica dacomposição química dos cimentos e Cromatografia, para análise da presença de formaldeído. Os resultados demonstraram que: todos os cimentos a base de óxido de zinco e eugenol apresentam óxido de zinco em altas concentrações. Os cimentos Target Canal Sealer e Endo fill, apresentam também na sua composição sulfato de bário e carbonato de bismuto. O cimento Endométhasone N apresentou apenas sulfato de bário e o Pulp Canal Sealer, prata metálica. Já o cimento a base de resina/hidróxido de cálcio, Sealer 26, apresenta óxido de bismuto, hidróxido de cálcio, dióxido de titânio e óxido de ferro. Os dois cimentos a base de MTA testados, Endo CPM Sealer e Obtura, apresentaram basicamente, silicato de cálcio. Componentes tais como: sulfato de bário e carbonato de cálcio foram encontrados no Endo CPM Sealer e hidróxido de cálcio e silicato de magnésio foram encontrados no Obtura. Em relação à presença de formaldeído, todos os materiais testados apresentaram formaldeído após a manipulação. Com base nestes dados, pode-se concluir que: 1) Não houve uma coincidência entre a composição divulgada pelo fabricante e a observada experimentalmente através da Difratometria de Raios X. Exceção a este são os cimentos a base de MTA; 2) apesar de nenhum fabricante indicar a presença de formaldeído na composição do material, este composto foi verificado em todos os cimentos testados, após manipulação. / Abstract: This study evaluated chemical composition (inorganic) and formaldehyde presence in root-canal sealers. Seven root-canal sealers were chosen: four based-zinc-oxide-eugenol (ZOE) (Targer Canal Sealer, Konne; Endo Fill, Dentsply; Endométhasone N, Septodont and; Pulp Canal Sealer, Kerr); two based-mineral trioxide aggregate (MTA) (Endo CPM Sealer, EGEO Dental and Obtura, Ângelus) and; one based-resin/calcium hydroxide (Sealer 26, Dentsply). All materials were mixed according to the manufacturer's instructions and inserted in one matrix (5 cm diameter and 0.5 cm thickness. X-Ray Powder Diffraction and Chromatography was performed after freshly mixed, for chemical composition and presence of formaldehyde, respectively. The results showed that: all ZOE materials presented higher concentrations of zinc-oxide. Target Canal Sealer and Endo fill based-OZE cements, showed barium sulfate and bismuth carbonate in the composition. Endométhasone N cement presented only barium sulfate and Pulp Canal Sealer, metal silver. Bismuth oxide, calcium hydroxide, titanium dioxide and iron oxide were showed in the based-resin/calcium hydroxide (Sealer 26). Both of MTA cements tested, Endo CPM Sealer and Obtura, presented calcium silicate. However, barium sulfate and calcium carbonate was found in the Endo CPM Sealer and magnesium silicate and calcium hydroxide in the Obtura. Regarding to the formaldehyde, all root-canal sealers tested showed this substance after took mixed. It was concluded that: 1) there was a great difference among present results and manufacturer's composition for almost all materials. This was notobserved for MTA root-canal sealers; 2) although no manufacturer has indicated the formaldehyde presence in their material composition, this component was verified in all materials tested. / Doutorado / Endodontia / Doutor em Clínica Odontológica

Orientador: Francisco Jose de Souza Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-08T06:01:23Z (GMT). No. of bitstreams: 1 Bruzadelli_RenataRibeiro_D.pdf: 917159 bytes, checksum: d156f2eb10c06d250bf44518788e959b (MD5) Previous issue date: 2006 / Resumo: O objetivo deste trabalho foi avaliar a eficácia do hipoclorito de sódio 5,25% e clorexidina gel 2% na remoção de pré-dentina nos terços cervical, médio e apical do canal radicular de incisivos inferiores humanos com polpas vitais e achatamento mésio-distal. Para isto, os canais foram instrumentados apenas na parede vestibular, preservando-se a superfície lingual para a verificação da ação de remoção das substâncias químicas auxiliares. Durante o preparo químico-mecânico, o volume e a freqüência da irrigação foram padronizados. Após a instrumentação, as raízes passaram por processamento histológico e foram analisadas em microscopia ótica para a verificação da presença e quantidade de pré-dentina remanescente na superfície lingual. A comparação estatística, realizada pelos Testes de Diferença de Proporções (P<0,01), mostrou que nos terços cervical, médio e apical, a remoção de pré-dentina proporcionada pela solução de hipoclorito de sódio 5,25% foi superior à clorexidina gel 2% e ao controle com soro fisiológico. Quando utilizada a mesma substância química, não houve diferença estatística entre os terços analisados. Concluímos que a solução de hipoclorito de sódio 5,25% é superior à clorexidina gel 2% e ao controle com soro fisiológico, quanto à remoção de pré-dentina, nas áreas não instrumentadas de canais achatados, nos terços analisados. Nenhuma substância química testada é capaz de remover completamente a pré-dentina nas áreas mais profundas das reentrâncias, em todas as amostras analisadas. Nas áreas instrumentadas e irrigadas, ocorre sempre a completa remoção de pré-dentina das paredes do canal radicular, com quaisquer das substâncias / Abstract: The aim of this study was to evaluate the predentin removal capacity of two substances used as irrigating substances in Endodontics ¿ 5.25% sodium hypochlorite and 2% chlorhexidine gel - on the apical, middle and cervical thirds from human mandibular incisors with vital pulps and mesio-distal flattened root canals. During the biomechanical preparation, volume and frequency of irrigants were standardizated. The instruments were used on the vestibular wall off the root canals and the removal capacity of the substances were studied in the lingual area. After instrumentation, and histological processing, the cross sections were examinated with an optic microscope in order to verify the presence and quantity of predentine on the lingual pole. The statistical analyses (P< 0,01) showed that 5.25% sodium hypochlorite presented higher capacity in removing predentin than 2% chlorhexidine gel and fisiologic solution in all thirds. CONCLUSIONS: 5.25% sodium hypochorite presented higher capacity in removing predentin than 2% chlorhexidine gel and fisiologic solution control. None of the substances completely removed all predentin in all samples. There was no difference on the root canal cleaning when used the same irrigant in the different thirds. In the areas touched by the endodontic instruments, the predentin was removed from the canal walls with all of the substances / Doutorado / Endodontia / Doutor em Clínica Odontológica

Orientador: Francisco Jose de Souza Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-15T12:42:13Z (GMT). No. of bitstreams: 1 Aragao_EgasMonizde_D.pdf: 10717512 bytes, checksum: f5b230e9a9be45626cd4cbee5274022d (MD5) Previous issue date: 2010 / Resumo: Para realizar a patência e ampliação dos forames apicais, com o objetivo de avaliar a evolução de sua forma, foi realizada a instrumentação dos canais de 48 dentes, 23 incisivos inferiores e 25 caninos, superiores ou inferiores. A instrumentação foi executada através de acesso radicular com brocas de Gates-Glidden, ampliação coroa-ápice com instrumentos manuais e, trabalhando 1mm além do comprimento do canal, ampliação do forame apical com três ou cinco limas tipo K. Os forames apicais foram avaliados ao microscópio eletrônico de varredura, antes da instrumentação, depois da ampliação com três limas e, numa terceira análise, após o uso de mais dois instrumentos - totalizando cinco limas. Nas fotomicrografias produzidas com 50, 100 e 150 aumentos, com o auxílio de um programa de análise de imagens, foram medidos oito raios da imagem de cada forame apical, a partir do centro de seu maior diâmetro. A divisão do desvio padrão destas medidas pela média refletiu numericamente a regularidade dos forames. A análise destes valores indicou que os forames apicais foram regularizados pela ampliação com três limas e com cinco limas, em ambas as situações, com diferença estatisticamente significativa para a forma inicial. A análise destes valores, dividindo os 48 dentes em grupos, indicou: a) haver maior regularização do forame apical em canais com menor curvatura radicular, com diferença estatisticamente significativa, quando comparados ao grupo com curvatura radicular moderada; e b) ocorrer o melhor resultado na regularização quando instrumentados os canais sem curva apical, com diferença estatisticamente significativa, quando comparados aos canais que apresentavam curva em seu final, fato observado mesmo em raízes retas. A ampliação dos forames apicais se mostrou capaz de regularizar sua forma, com melhor desempenho em canais menos curvos, tornando-os mais circulares, exceção feita aos dentes cujos canais apresentavam curva apical, nos quais houve deformação dos forames / Abstract: The resulting shape of the apical foramens of 48 teeth - 23 lower incisors and 25 upper or lower cuspids - was evaluated after enlargement with 3 or 5 K-type files in root canal treatment performed with radicular access before the crown-down instrumentation technique and followed by serial instrumentation of the canal, with the file going beyond the apical foramen, so as to enlarge it. The apical foramens of each one of the teeth were evaluated with scanning electron microscope, before the instrumentation, after the enlargement with the first apical file and two other instruments, plus a third assessment after the use of two more instruments - totaling four files in addition to the initial anatomical file. In the photomicrographs, 100x and 150x magnification, eight radiuses of each apical foramen were measured with the help of an image analysis software from the center of their largest diameter. The division of the standard deviation of those measurements by the average reflects the regularity of the foramens in numerical terms. The analysis of the numbers indicated that the apical foramens were evened by the enlargement with 3 and 5 files, in both cases with statistically significant difference from the original shape. Such analysis, dividing the 48 teeth into groups, showed: a) greater evenness of the apical foramen in canals with less pronounced root curvature, with statistically significant difference when compared to the moderate curvature group; and, b) better result in teeth with no root canal apical curvature, with statistically significant difference, when compared to teeth with root canal apical curvature, a fact observed even in straight roots. The enlargement of apical foramens was proven to even their shape, with better result in less curved canals, rendering them more circular, with the exception of teeth with canals having apical curvature, in which the foramens suffered deformation / Doutorado / Endodontia / Doutor em Clínica Odontológica

Orientador: Francisco José de Souza Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T06:53:49Z (GMT). No. of bitstreams: 1 Campos_GabrielRocha_D.pdf: 1446071 bytes, checksum: b99a2aea05a01a53d5dead215f272a91 (MD5) Previous issue date: 2013 / Resumo: O objetivo do presente estudo foi avaliar o efeito da ampliação foraminal e extrusão intencional de cimento Endomethasone no processo de reparo periapical, além do efeito da ação antimicrobiana de duas substâncias químicas auxiliares utilizadas durante preparo químico-mecânico. Para tanto, 20 raízes de cães adultos jovens, com polpa necrótica e associadas à lesão periapical crônica, foram preparadas endodonticamente com ampliação foraminal e variando-se a substâncias químicas auxiliares: hipoclorito de sódio 2,5% (NaOCl) e clorexidina gel 2% (CG). Todos os canais radiculares foram obturados em sessão única e com extravasamento intencional de cimento para a região periapical. Coletas para análise microbiológica foram realizadas para avaliar o nível de contaminação bacteriana antes e imediatamente após o preparo químico-mecânico. Após um período de 180 dias da obturação dos canais radiculares, os animais foram sacrificados e as peças processadas laboratorialmente para análise histopatológica em H.E. e Brown e Breen. Os espécimes foram avaliados quanto às características do infiltrado inflamatório e condições de reparo periapical. Após aplicado teste estatístico de Wilcoxon os resultados mostraram uma redução significativa para a contagem das Unidades formadoras de colônias (UFC) após o preparo químico-mecânico (p = 0,4427), sem diferenças estatísticas significantes entre as substâncias químicas utilizadas NaOCl 2,5% (p = 0,0051) e CG (p = 0,0244). A análise histopatológica mostrou que áreas de reabsorção foram reparadas por neoformação cementária e ao redor do cimento extravasado no ligamento periodontal a reação inflamatória do tipo crônica persistiu. As substâncias químicas utilizadas são antimicrobianos efetivos durante o preparo químico-mecânico e o reparo periapical ocorreu por deposição de cemento ou por tecido conjuntivo fibroso encapsulando o cimento obturador extravasado / Abstract: The aim of the current study is to evaluate the effect of amplification of apical foramen and intentional extrusion with Endomethasone sealer in the periapical repair process, in addition to the effect of the antimicrobial action of two auxiliary chemical substances used during the chemical-mechanical preparation. A total of 20 roots of young adult dogs were used, with pulp necrosis and associated to the chronic periapical lesion, prepared endodontically with amplification of apical foramen and varying auxiliary chemical substances: sodium hypochlorite 2.5% (NaOCL) and chlorhexidine gel 2% (CG). All root canals were obturated in a single session, and with intentional extravasation of the sealer to the periapical region. Sampling for microbiological analysis was made in order to evaluate the level of bacterial contamination before and immediately after the chemical-mechanical preparation. After 180 days of obturation of the root canals the animals were euthanized and the parts were processed in lab for histopathological analysis in H.E. and Brown and Brenn. The specimens were evaluated for the characteristics of the inflammatory infiltrate and the periapical repair conditions. After applying the statistical test of Wilcoxon, the results showed a significant reduction for counting the colony-forming units (CFU) after the chemical-mechanical preparation (p = 0.4427), without significant statistical differences between the chemical substances used, NaOCl2.5% (p = 0.0051) and CG (p = 0.0244). The histopathological analysis showed that the reabsorption areas were repaired by cement neoformation and around the cement extravasated in the periodontal ligament the chronic-type inflammatory reaction persisted. The chemical substances used are antimicrobials effective during the chemical-mechanical preparation, and the periapical repair occurred by cement deposition or by fibrous conjunctive tissue encapsulating the extravasated obturator cement / Doutorado / Endodontia / Doutor em Clínica Odontológica

Indiana University-Purdue University Indianapolis (IUPUI) / Pulpotomy procedures for the treatment of pulp exposure or disease have traditionally used an approach from the occlusal surface in primary molars, with a rotating bur or a spoon excavator being used to excise the pulp under clean conditions and with a medicament being applied to the amputation site. The purpose of this study was: (1) to determine the feasibility of performing a sterile scalpel excision of coronal pulpal tissue and (2) to evaluate wound healing after a shield has been placed to prevent all substances from touching the blood clot at the amputation site. Using sterile operating room procedures, four of five teeth in five dogs were rendered free of cultivable bacteria after antimicrobial treatments were applied. These findings replicated a preliminary in vivo experiment of 45 teeth which demonstrated that antimicrobial agents applied to tooth enamel in dogs were effective beyond the 0.001 level of significance, as compared to a control group. Furthermore, in the main study, negative cultures were obtained during 72 percent of the trials following each of the five major steps in the pulpotomy procedure. This included 80 percent negative cultures for bacteria after pulpal excision and blood clot formation, and 100 percent freedom from cultivable bacteria after a resin diaphragm was cemented to place. In eight experimental teeth (three from the preliminary study and all five from the main study) the buccal dentin over the coronal portion of the pulp was removed by use of a tissue-protecting device without grossly macerating the pulpal tissue. In seven of these eight teeth, the coronal portion of the pulp tissue was amputated with a scalpel severance and pulpal biopsies were removed through the buccal preparation. In all eight teeth, the cavity preparation was accomplished without applying medicaments to the blood clot at the amputation site. A resin-stainless steel diaphragm was constructed under sterile conditions and secured in a buccal preparation without touching the pulpal amputation for a convalescence of 14-21 days, and this shield provided a buccal wall for closure with an amalgam restoration. In one animal which had not received a previous autotransfusion for medical research, histologic sections of the pulp tissue in two root canals demonstrated satisfactory wound healing (a moderate and a mild inflammatory infiltrate was considered reversible). Three of the five dogs in the main study exhibited pulpal necrosis which was attributed to an interference in the immune system by previous autotransfusion research, and histologic evaluation of pulpal wound healing was therefore inconclusive. This study demonstrates that the enamel surface can be rendered free of cultivable bacteria in the dog and the operative site can be maintained in this condition throughout pulpotomy, with the coronal portion of the pulp being removed without grossly macerating the pulp. Under these conditions there appears to be a potential for satisfactory wound healing, with possible implications for the clinical situation.