Effect of different disinfection protocols in bacterial viability of an intraradicular biofilm formed in situ

Abstract The present study aimed to evaluate bacterial viability after the use of different disinfection protocols in root canals infected with a multispecies biofilm (MB) formed in situ. Palatal roots with a single canal were obtained from extracted maxillary molars and sterilized before being inserted into the mouth. The roots were contaminated with a MB in an intraoral appliance worn by ten volunteers. All volunteers wore six roots simultaneously in two intraoral devices for 21 days. One root from each volunteer was assigned to each group (n=10): PUI - passive ultrasonic irrigation; EC - Easy Clean; XPF - XP-endo Finisher; aPDT - antimicrobial photodynamic therapy; CI - conventional irrigation; and NC - negative control. The samples were evaluated under confocal laser scanning microscopy. The percentage of viable cells (VC) was calculated over the total percentage of MB biovolume. Data were statistically analyzed (α=5%). The cell viability in the entire root canal or for each third was compared between groups (Kruskal-Wallis test, Dunn post-hoc test) and for the same group (Friedman test, Dunn post-hoc test). Disinfection protocols were not significantly different from each other (P>.05). Samples in EC, PUI, and aPDT had lower cell viability than in NC (P<.05). In the coronal third of samples in the EC, XPF, PUI and aPDT, the percentage of VC biovolume was lower than in the NC (P<.05). The percentage of VC in EC samples was lower in the coronal and middle thirds than in the apical third (P<.05). EC, PUI and aPDT had significant effects on cell viability in intraradicular multispecies biofilm formed in situ when compared with untreated samples.

Resumo O presente estudo teve como objetivo avaliar a viabilidade bacteriana após o uso de diferentes protocolos de desinfecção em canais radiculares infectados com um biofilme multiespécies (MB) formado in situ. Raízes palatinas com canal único foram obtidas de molares superiores extraídos e esterilizadas antes de serem inseridas na boca. As raízes foram contaminadas com MB em um aparelho intraoral usado por dez voluntários. Todos os voluntários usaram seis raízes simultaneamente em dois dispositivos intrabucais por 21 dias. Uma raiz de cada voluntário foi atribuída a cada grupo (n=10): PUI - irrigação ultrassônica passiva; EC - Easy clean; XPF - XP-endo Finisher; aPDT - terapia fotodinâmica antimicrobiana; IC - irrigação convencional; e, NC - controle negativo. As amostras foram avaliadas em microscopia confocal de varredura a laser. A porcentagem de células viáveis (VC) foi calculada sobre a porcentagem total do biovolume de MB. Os dados foram analisados estatisticamente (α=5%). A viabilidade celular em todo o canal radicular ou em cada terço foi comparada entre os grupos (teste de Kruskal-Wallis, teste post-hoc de Dunn) e no mesmo grupo (teste de Friedman, teste post-hoc de Dunn). Os protocolos de desinfecção não foram significativamente diferentes entre si (P>0,05). Amostras dos grupos EC, PUI e aPDT apresentaram menor viabilidade celular do as do NC (P<0,05). No terço cervical das amostras do EC, XPF, PUI e aPDT, a porcentagem de biovolume de VC foi menor do que no NC (P<0,05). A porcentagem de VC nas amostras do EC foi menor nos terços cervical e médio do que no terço apical (P<0,05). EC, PUI e aPDT tiveram efeitos significativos na viabilidade celular do biofilme multiespécies intrarradicular formado in situ quando comparado com amostras não tratadas. Estudos clínicos devem investigar o papel da redução de cargas bacterianas viáveis no sistema de canais radiculares para o sucesso do tratamento endodôntico.

Physicochemical properties of three bioceramic cements

Abstract: This study aimed to compare the physicochemical properties of MTA Angelus (MTA-A), MTA Repair HP (MTA-HP), and Biodentine (BD). Setting times (n = 7) were determined in accordance with ASTM C266-15. Solubility (n = 11), pH (n = 10), and calcium ion release (n = 10) were evaluated up to 28 days in accordance with ANSI/ADA specification no. 57. Radiopacity was assessed by ANSI/ADA (n = 10) and the tissue simulator method (n = 10). In both methods, the specimens were radiographed using an aluminum stepwedge and the digital radiographs were analyzed in Adobe Photoshop, determining the mean grayscale pixel values of the materials, of the 3-mm aluminum stepwedge, and of the dentin, the latter of which was analyzed on the tissue simulator. The data obtained from each test were statistically analyzed and compared (p < 0.05). MTA-A presented longer final setting time compared with the other materials. There were no significant differences in the mass values of materials during the experiment. All materials presented an alkaline pH. BD promoted greater calcium ion release in most of the experimental periods. All materials presented appropriate radiopacity. BD showed lower radiopacity than MTA-A in the tissue simulator method. All groups presented higher radiopacity in the tissue simulator when compared with the ANSI/ADA method. MTA-A, MTA-HP, and BD showed appropriate physicochemical properties and radiopacity, and were considered suitable to be used in clinical practice.

The effectiveness of rotary and reciprocating techniques in curved root canals retreatment: a micro- CT analysis

Introduction: Different NiTi rotary systems have been developed to improve efficiency and retreatment success rates. Aim: To evaluate the Protaper Universal retreatment system and WaveOne instrument in removing the filling material from curved canals during retreatment. Materials and Methods: Thirty mesial root canals of extracted human mandibular molar teeth were randomly allocated into 2 groups (n=15). In the PT group, retreatment was performed with ProTaper Universal Retreatment according to the manufacturer's instructions. In the WO group, was used WaveOne Primary. ProTaper Universal F2 and F3 were used to achieve the apical diameter in both groups. The samples were scanned by micro-computed tomography pre and postoperatively to evaluate the filling material remaining. The percentage of material filling was compared between groups using Student's T test and in the same group among thirds was compared using Kruskal-Wallis followed by Dunn's post hoc test. Results: The filling material remaining was not statistically different between the groups (p≥0.05). The apical third presented a greater amount of remaining filling material when compared with the cervical third for both groups (p<0.05). Conclusion: Rotary and reciprocating techniques can effectively, but not completely, remove the filling materials from the root canal system. The apical third presented a more significant amount of remaining filling material.

Influence of photobiomodulation therapy on root development of rat molars with open apex and pulp necrosis

Abstract This study aimed to evaluate the role of photobiomodulation (PBM) in apexification and apexogenesis of necrotic rat molars with an open apex. Rat molars were exposed to the oral environment for 3 weeks. Canals were rinsed with 2.5% NaOCl and 17% EDTA, filled with antibiotic paste and sealed. After 7 days, canals were rinsed and divided into six groups (n=6): mineral trioxide aggregate (MTA); blood clot (BC); human dental pulp stem cells (hDPSC); MTA+PBM; BC+PBM; and hDPSC+PBM. In hDPSC groups, a 1% agarose gel scaffold was used. Two groups were not exposed: healthy tooth+PBM (n = 6), healthy tooth (n = 3); and one was exposed throughout the experiment: necrotic tooth (n = 3). In PBM groups, irradiation was performed with aluminum gallium indium phosphide (InGaAlP) diode laser for 30 days within 24-h intervals. After that, the specimens were processed for histological and immunohistochemical analyses. Necrotic tooth showed greater neutrophil infiltrate (p < 0.05). Necrotic tooth, healthy tooth, and healthy tooth+PBM groups showed absence of a thin layer of fibrous condensation in the periapical area. All the other groups stimulated the formation of a thicker layer of fibers (p < 0.05). All groups formed more mineralized tissue than necrotic tooth (p < 0.05). PBM associated with MTA, BC, or hDPSC formed more mineralized tissue (p < 0.05). MTA+PBM induced apexification (p < 0.05). Rabbit polyclonal anti-bone sialoprotein (BSP) antibody confirmed the histological findings of mineralized tissue formation, and hDPSC groups exhibited higher percentage of BSP-positive cells. It can be concluded that PBM improved apexification and favored apexogenesis in necrotic rat molars with an open apex.

Validation of self-reported history of root canal treatment in a southern Brazilian subpopulation

Abstract The aim of this study was to assess self-reported history of root canal treatment (SRHRCT) as a method for detecting the presence of root canal treatment (RCT) and apical periodontitis (AP) in a southern Brazilian subpopulation. In this cross-sectional study, 136 military police officers from the city of Porto Alegre, Brazil, were included. The participants were interviewed and full-mouth periapical radiographs were taken. A calibrated examiner determined the presence of RCT and AP by applying standardized criteria. The diagnostic accuracy of SRHRCT was calculated separately for RCT and AP. Accuracy, sensitivity, specificity, positive and negative predictive values (+PV and -PV), efficiency, and positive and negative likelihood ratios (+LR and -LR) were estimated. The mean age of the participants was 34.1 ± 10.4 years and 88.2% were males. Overall, SRHRCT demonstrated high sensitivity and specificity for RCT, but not for AP: sensitivity (RCT = 0.960, AP = 0.757) and specificity (RCT = 0.835, AP = 0.631). The estimated values for PV and LR were: +PV (RCT=0.777, AP=0.396), -PV (RCT = 0.972, AP = 0.890), +LR (RCT = 5.853, AP = 2.057), and -LR (RCT = 0.046, AP = 0.383). SRHRCT proved to be a good predictor of the presence of RCT, but a weak predictor of AP in this subpopulation.

Efeito do hipoclorito de cálcio na resistência de adesão do cimento obturador AH Plus à dentina / Effect of calcium hypochlorite on the bond strength of the AH Plus sealer to dentin

Objetivo: avaliar o efeito do uso de hipoclorito de cálcio (Ca(OCl)2) como irrigante na resistência de adesão do cimento AH Plus (De Trey-Dentsply, Konstanz, Alemanha) à dentina pelo teste de micro push-out. Materiais e método: trinta e três dentes humanos monorradiculares foram seccionados transversalmente na junção amelocementária e divididos em três grupos: hipoclorito de sódio (NaOCl) 2,5%, hipoclorito de cálcio 2,5% e soro fisiológico. Os canais foram preparados, irrigados ao final com EDTA 17% e obturados com cones de guta percha e cimento AH Plus. Após armazenagem por 7 dias, em 100% de umidade e a 37°C, os dentes foram seccionados transversalmente ao longo do eixo da raiz. Foram obtidas três fatias de cada dente (n=33), que foram submetidas ao ensaio de push-out. O tipo de falha foi analisado por fractografia e classificado em falha adesiva, coesiva ou mista. Os valores de resistência de união foram analisados pelo teste de Kruskal-Wallis, com nível de significância de 95%. Resultados: o grupo Ca(OCl)2 2,5% apresentou a menor média de resistência de adesão, diferindo estatisticamente do NaOCl e do soro fisiológico (p<0,05). Não houve diferença estatística entre os grupos irrigados com soro e NaOCl (p>0,05). Conclusões: a falha predominante em todos os grupos foi a do tipo adesiva. O Ca(OCl)2 2,5% teve um efeito negativo sobre a força de adesão do AH Plus à dentina radicular quando comparado ao NaOCl 2,5%. (AU)

Objective: to evaluate the effect of calcium hypochlorite (Ca(OCl)2) as an irrigant on the bond strength of the AH Plus sealer (De Trey-Dentsply, Konstanz, Germany) to dentin, using the micro push-out test. Materials and method: thirty-three single-rooted human teeth were cross-sectioned on the cementoenamel junction and divided into three groups: 2.5% sodium hypochlorite (Na- OCl), 2.5% calcium hypochlorite, and saline solution. The canals were prepared, irrigated with 17% EDTA at the end, and filled with gutta-percha cones and AH Plus sealer. After being stored for seven days at 100% humidity and 37ºC, the teeth were cross-sectioned along the root axis. Three slices of each tooth (n=33) were obtained and subjected to the push-out test. Failure mode was analyzed by fractography and classified as adhesive, cohesive, or mixed. Bond strength values were analyzed by the Kruskall-Wallis test at 95% significance level. Results: the 2.5% Ca(OCl)2 group showed the lowest bond strength mean, differing statistically from 2.5% NaOCl and saline solution (p<0.05). There was no statistical difference between the groups irrigated with saline solution and NaOCl (p>0.05). Conclusion: the adhesive failure was predominant in all groups. The 2.5% Ca(OCl)2 had a negative effect on the bond strength of AH Plus to the root dentin when compared to 2.5% NaOCl. (AU)

Performance of progressive and constant tapered instruments rotary systems at canal preparation / Desempenho de sistemas endodônticos rotatórios constante e progressivo no preparo do canal radicular

ABSTRACT Objective: The aim of this study was to compare the performance of two nickel-titanium rotary systems regarding the preparation time, final shape of canal, incidence of aberration, transportation, and fracture of instrument. Methods: A total of 40 simulated canals in resin blocks with 30o curves and a length of 17 mm were divided randomly into two groups: preparation with ProTaper and BioRaCe systems up to F5 and BR5 respectively. Pre- and post-operative canal images were taken and superimposed in order to identify aberrations, transportation, and to take measurements of the canal width. In addition, the preparation time and instrument fractures were recorded. The data were analyzed using Student's t test. Results: There is no difference (p>.05) comparing the systems regarding preparation time, canal aberration, and instrument fracture rates. The progressive tapered instruments of ProTaper prepared significantly larger canal widths in the apical third (p<.05). Conclusion: Overall, both systems provided safe canal preparation, associated with few canal aberrations and instrument fractures.

RESUMO Objetivo: Comparar o desempenho de dois sistemas rotatórios em relação ao tempo de preparo, formato final e alterações do canal, desvio e fratura de instrumento. Métodos: Um total de 40 canais simulados em blocos de resina com curvatura de 30o e comprimento de 17 mm foram divididos randomicamente nos sistemas ProTaper e BioRaCe preparados até F5 e BR5 respectivamente. Imagens pré e após o preparo dos canais foram obtidas e superpostas para identificação de alterações de forma, desvios e largura. O tempo de preparo e fratura de instrumentos também foram avaliados. Os dados foram analisados por teste t de Student. Resultados: O tempo de preparo, alterações de forma e taxa de fratura de instrumentos não teve diferença entre os dois sistemas avaliados (p>0,05). Os instrumentos progressivos do ProTaper resultou em canais significativamente mais largos no terço apical (p<0,05). Conclusão: Os dois sistemas rotatórios avaliados resultaram em preparo endodôntico seguro, com poucas alterações e fratura de instrumento.

Avaliação de três técnicas de instrumentação com diferentes diâmetros apicais na formação de smear layer / Evaluation of three instrumentation techniques with different apical diameters on smear layer formation

Objetivo: avaliar os efeitos de diferentes instrumentações na formação de smear layer no terço apical de 90 raízes mesiobucais de molares superiores por microscopia eletrônica de varredura (MEV). Materiais e método: três grupos foram formados baseados nas técnicas utilizadas: instrumentação manual, sistema rotatório K3 e sistema reciprocante NSK. Os grupos foram subdivididos em três, de acordo com o diâmetro apical: #30, #35 ou #40. Após o preparo, as raízes foram seccionadas no sentido transversal, separando os terços apicais do restante das raízes; esses terços foram divididos em duas metades e preparados para MEV. A formação de smear layer na superfície do canal radicular e os túbulos den-tinários foram avaliados por escores num aumento de 1.000×. Os dados foram analisados pelo teste Kruskal-Wallis complementado pelo teste de Dunn (p < 0.05). Resultados: o aumento no diâmetro do preparo apical não influenciou na formação de smear layer nas paredes dentinárias. Conclusão: apesar das técnicas e dos diâmetros apicais utilizados durante o preparo, nenhuma parede livre de smear layer foi observada.

Resin-based sealer penetration into dentinal tubules after the use of 2% chlorhexidine gel and 17% EDTA: in vitro study

Aim: To evaluate, by confocal laser scanning microscopy (CLSM), the influence of 17% EDTA final irrigation on the penetration of an endodontic resin-based sealer into dentinal tubules after use of 2% chlorhexidine gel. Methods: Forty extracted bovine incisors were instrumented according to the groups: G1 - root canal preparation with 2% chlorhexidine gel (n=10); G2 - root canal preparation with 2% chlorhexidine gel and final irrigation with 17% EDTA (n=10); G3 - root canal preparation with saline and final irrigation with 17% EDTA (n=10); G4 - root canal preparation with saline (n=10). The samples were filled with gutta-percha using AH Plus sealer with rhodamine B fluorescent dye. After seven days, the teeth were sectioned at the coronal, middle, and apical thirds and viewed under confocal microscope. The most representative area of penetration depth was measured in each group. Statistical significance for the sealer penetration area was determined among groups using one-way ANOVA followed by Tuckey test. For thirds comparison, in each group, data were statistically analyzed using Friedman test (p<0.05). Results: The maximum penetration was provided by G2 - 2% chlorhexidine + EDTA (p=0.000). According to this criterion, no differences were found among the other groups and among thirds within the same group. Conclusions: Based on these results, the use of 17% EDTA should be indicated after root canal preparation with 2% chlorhexidine gel for smear layer removal, enhancing the AH Plus sealer penetration.

Efficacy of an Organic Solvent and Ultrasound for Filling Material Removal

The aim of this study was to investigate whether a final rinse with Endosolv R® solvent and ultrasound resulted in cleaner root canal walls during endodontic retreatment. A total of 56 extracted premolar teeth were manually instrumented using a step-back flare technique and filled with gutta-percha and AH Plus sealer. After 9 months, the canals were retreated by removing the gutta-percha and sealer with ProTaper Universal Retreatment and rotary preparation with ProTaper Universal System up to an F5 file. As a final step, the teeth were randomly divided in 4 groups (n=14) and were subjected to passive ultrasonic irrigation (PUI) with either Endosolv R or distilled water. In the control groups, the irrigants were left undisturbed. Roots were cleaved and examined under scanning electron microscopy (SEM), and the amount of filling remnants on the canal walls was assessed by two calibrated examiners in a blinded fashion. Data were analyzed by the Kruskal-Wallis test and the Student-Newman-Keuls post hoc test (α=0.05). All groups presented filling debris in the three root canal thirds after retreatment. There were no significant differences between the groups or among the root canal thirds within each group (p>0.05). PUI with Endosolv R was not effective in the removal of filling debris from root canal walls.

O objetivo deste estudo foi investigar se a irrigação final com o solvente Endosolv R® e ultrassom promovia maior limpeza nas paredes do canal radicular durante o retratamento endodôntico. Um total de 56 dentes pré-molares extraídos foram instrumentados manualmente utilizandose a técnica escalonada e obturados com guta-percha e cimento AH Plus. Após nove meses, os canais foram retratados através da remoção da guta-percha e do cimento com Protaper Universal Retratamento e preparo rotatório com Sistema Protaper Universal até o instrumento F5. Após essa etapa, a amostra foi aleatoriamente dividida em quatro grupos (n=14) e os dentes submetidos à irrigação ultrassônica passiva (PUI) associada ao solvente Endosolv R ou à água destilada. Nos grupos controle, os irrigantes permaneceram sem agitação. Em seguida as raízes foram clivadas e examinadas sob microscopia eletrônica de varredura (MEV) para que a quantidade de material obturador remanescente nas paredes do canal fosse avaliada por dois examinadores treinados de forma cega. Os dados foram analisados através dos testes de Kruskal-Wallis e de Student-Newman-Keuls post hoc (α=0.05). Todos os grupos apresentaram resíduos de materiais obturadores nos três terços do canal radicular após o retratamento. Não houve diferenças significativas entre os grupos ou entre os terços dos canais em cada um dos grupos (p>0,05). Concluiu-se que PUI com Endosolv R não foi efetiva para a remoção de remanescentes de material obturador das paredes do canal radicular.

Dissolução de cimentos endodônticos resinosos por solventes orgânicos em diferentes intervalos de tempo / Dissolution of resin-based root canal sealers by organic solvents at different time intervals

Objetivo: O objetivo deste estudo foi investigar se o tempo deexposição dos cimentos endodônticos resinosos a solventesorgânicos afeta sua solubilidade. Materiais e métodos: Moldes desilicona de condensação circulares padronizados (4,47 mm de largurapor 1,5 mm de altura) foram preenchidos com quatro cimentosendodônticos resinosos recém-misturados (Acroseal®, Epiphany®, AHPlus® e Sealer26®) e armazenados a 37°C por duas semanas (n=08).Depois de inspecionado, cada corpo-de-prova foi pesado três vezes eindividualmente imerso em Citrol®, Endosolv R®, hipoclorito de sódio a2,5% ou água destilada (controle) por 10 minutos, 02 horas e 24horas. Nos intervalos testados, a perda média de cada materialobturador imerso nos solventes foi determinada. Os dados foramanalisados estatisticamente com ANOVA de duas vias, Bonferronipost hoc e teste de Pearson (α=0,05). Resultados: O Endosolv R® foisignificativamente mais eficiente na dissolução do Sealer26® do que aágua destilada (grupo controle), óleo de laranjas e hipoclorito desódio 2,5%. O Citrol® e o hipoclorito de sódio 2,5% demonstrarammaior potencial para dissolver o cimento Sealer26® no intervalo de 24horas, quando comparados ao grupo controle. As diferenças de peso entre os cimentos imersos em hipoclorito de sódio 2,5% não semostraram estatisticamente significantes. A solubilidade foisignificativamente correlacionada com o tempo de exposição somentequando o Endosolv R® (+0,829) ou a água destilada (+0,441) foramempregados. Conclusão: A dissolução de cimentos à base de resinafoi afetada pelo intervalo de exposição e tipo de solvente orgânicoutilizado. Endosolv R® e períodos mais longos de exposiçãopromoveram maior solubilização dos cimentos de base resinosa testados.

Aim: The aim of this study was to investigate whether time exposureof resin-based root canal sealers to organic solvents affects theirsolubility. Materials and methods: Standardized circular siliconmoulds (4.47mm wide and 1.5mm high) were filled with four freshlymixed resin-based root canal sealers (Acroseal®, Epiphany®, AHPlus® and Sealer 26®) and stored at 37° for two weeks (n=8). Afterinspection, each sample was weighted thrice and individuallyimmersed in Citrol®, Endosolv R®, 2.5% sodium hypochlorite ordistilled water for 10, 120 and 1440 min. In the tested intervals, themean weight loss of each filling material immersed in solvents wasdetermined. Data were statistically analyzed by Two-wayANOVA, Bonferroni post hoc and Pearson tests (α=0.05). Results:Endosolv ® R was significantly more effective in dissolving Sealer26 ®than distilled water (control group), orange oil and 2.5% sodiumhypochlorite. Citrol® and 2.5% sodium hypochlorite showed thegreatest potential to dissolve Sealer26 ® within 24 hours, compared tothe control group. The weight losses between sealers immersed insodium hypochlorite 2.5% were not statistically significant. Solubilitywas significantly correlated with exposure intervals only whenEndosolv R® (+0,829) or double-distilled water (+0,441) wereapplied. Conclusion: Dissolution of resin-based root canal sealerswas affected by exposure interval and type of organic solvent used.Endosolv R® and longer exposure intervals promoted greatersolubilization of the resin-based sealers tested.

Resilon and Gutta-percha cones: an evaluation of biocompatibility in the connective tissue of rats / Avaliação da biocompatibilidade de cones de Resilon e de gutapercha em tecido conjuntivo de ratos

Objective: This study tested tissue response to gutta-percha or Resilon cones at 7, 14, 30, 60 and 90 days. Methods: Thirty Wistar rats each received three subcutaneous implants of polyethylene tubes containing: GP (gutta-percha); R (Resilon); CG (control group ? empty tube). After histological processing, sections were analyzed by a calibrated examiner, using a light microscope to identify the presence of neutrophils, lymphocytes and plasma cells, eosinophils, macrophages and giant cells, fibrous capsule and abscesses, by an examiner using a light microscope. Kruskal-Wallis and multiple comparison tests were used for the statistical analysis. Results: There were no differences for the macrophages and giant cells, lymphocyte and plasma cell infiltrate, eosinophils, fibrosis or abscesses. Higher neutrophil infiltrate scores were observed at 7 days for groups R and CG (p? 0.05). In group R, the number of neutrophils decreased with time (p= 0.017). Conclusion: The results of the present study demonstrate that Resilon cones are well tolerated by tissues and have acceptable biocompatibility, in the same way as gutta-percha cones.

Objetivo: Avaliar a biocompatibilidade de cones de guta-percha e Resilon em tecido conjuntivo de ratos nos períodos de 7, 14, 30, 60 e 90 dias.Métodos: Trinta ratos Wistar receberam três implantes de tubos de polietileno contendo: GP (guta-percha), R (Resilon), CG (grupo controle - tubo vazio). Após cada período experimental, foi realizado o processamento histológico e os cortes foram analisados por um examinador calibrado, com auxílio de microscópio de luz para identificar a presença de neutrófilos; linfócitos e células plasmáticas; eosinófilos, macrófagos e células gigantes; cápsula fibrosa e abscessos. Para a análise estatística foram utilizados os testes de Kruskal-Wallis e de comparações múltiplas. Resultados: Não houve diferença para os macrófagos e células gigantes, linfócitos e células plasmáticas; eosinófilos, fibrose ou abscesso. Foram observadas altas taxas de infiltrado neutrofílico aos sete dias nos grupos R e GC (p ? 0,05). No grupo R, o número de neutrófilos diminuiu com o tempo (p = 0,017).Conclusão: Os resultados do estudo demonstram que os cones de Resilon são bem tolerados pelos tecidos e possuem biocompatibilidade aceitável, como cones de guta-percha.

Adhesion of real seal to human root dentin treated with different solutions

The aim of this study was to evaluate the effects of different irrigants on sealer-dentin bond strength when using Real Seal. Thirty single-rooted teeth were divided into 3 groups. In one group, the teeth were irrigated with 3 mL of 2.5% NaOCl after each file change, flushed with 17% EDTA for 3 min and finally rinsed with 3 mL of 2.5% NaOCl. In the other two groups, rinse with NaOCl was replaced with 2% chlorhexidine gluconate (CHX) and 0.9% saline, respectively. Each root was sectioned transversally into apical, middle and coronal thirds to obtain 2-mm-thick slices. Each slice was filled with Real Seal and Resilon. Push-out test was used to analyze bond strength and failure modes were classified as adhesive, cohesive or mixed, according to SEM observations. The push-out test did not reveal any statistically significant difference (p>0.05) between the irrigants. However, the groups exhibited significantly different (p<0.05) bond strengths in terms of the root canal third. Higher bond strength was observed at the apical third when compared with coronal third, while middle third presented intermediary values. Fifteen specimens were analyzed by SEM (5 per group). Eleven specimens exhibited adhesive failures (5 in saline, 4 in NaOCl and 2 in CHX group); 2 cohesive failures were observed in the CHX group, and 1 mixed failure each was observed in the CHX and NaOCl groups. The tested irrigants did not influence the bond strength of Resilon and Real Seal to dentin. The apical third exhibited higher mean bond strengths and adhesive failures were predominant.

O objetivo deste estudo foi avaliar os efeitos de diferentes soluções irrigadoras na resistência adesiva do Real Seal à dentina radicular. Trinta dentes monorradiculares foram divididos em 3 grupos: Grupo 1 - os dentes foram irrigados com 3 mL de NaOCl 2,5% após cada troca de instrumento, irrigados com EDTA 17% por 3 min e lavagem final com NaOCl 2,5%. Nos Grupos 2 e 3, o NaOCl foi substituído por digluconato de clorexidina 2% (CHX) e solução salina 0,9%, respectivamente. Cada raiz foi seccionada transversalmente nos terços apical, médio e cervical para obter fatias de 2 mm de espessura. Cada slice foi obturado com Real Seal e Resilon. Teste de push-out foi usado para analisar a resistência adesiva e os padrões de falha foram classificados como adesiva, coesiva e mista de acordo com MEV. O teste de push-out não revelou diferença estatisticamente significante entre os irrigantes (p<0,05). Porém, os grupos exibiram diferentes valores de resistência adesiva de acordo com o terço radicular (p>0,05). Maior resistência adesiva foi observada na região apical quando comparado com o terço cervical, enquanto que o terço médio apresentou valores intermediarios. Quinze espécimes foram analisados através de MEV (5 por grupo). Onze espécimes exibiram falhas adesivas (5 no grupo da solução salina, 4 no grupo NaOCl e 2 na CHX); duas falhas coesivas foram observadas no grupo CHX e uma falha mista foi observada no grupo da CHX e uma no NaOCl. Os irrigantes testados não influenciaram a resistência adesiva do Resilon e do Real Seal à dentina radicular. O terço apical apresentou maior resistência adesiva e falhas adesivas foram predominantes para todos os grupos.

Calcium hydroxide removal: effectiveness of ultrasonic and manual techniques / Remoção de hidróxido de cálcio: Eficácia das técnicas ultrassônica e manual

PURPOSE: Different techniques have been proposed to improve the removal of calcium hydroxide. The purpose of this in vitro study was to compare the effectiveness of ultrasound and manual techniques in the removal of calcium hydroxide from root canals. METHODS: Thirty-eight single-rooted teeth were divided into two groups of 19 teeth each. The teeth were prepared using the crown-down technique with an apical master file #50. After shaping, the canals were radiographed and dressed with calcium hydroxide. After 14 days, the calcium hydroxide was removed with the ultrasound technique in group I and through manual filing in group II. The teeth were then radiographed again to evaluate the removal of the paste. To assess the calcium hydroxide removal, the radiographs were scanned and analyzed based on the gray levels. The independent samples and Student's t-tests (α=0.05) were used for each group to compare the efficacy of calcium hydroxide removal between the groups and among thirds (cervical, middle and apical). RESULTS: There was no difference between ultrasound and manual techniques in the removal of calcium hydroxide from root canals. There were no statistical differences among the thirds analyzed. CONCLUSION: Neither manual nor ultrasonic techniques completely removed calcium hydroxide from the root canal.

OBJETIVO: Diferentes técnicas são propostas para melhorar a remoção da pasta de hidróxido de cálcio. O objetivo do presente estudo in vitro foi comparar a efetividade das técnicas ultrassônica e manual para a remoção do hidróxido de cálcio do canal radicular. METODOLOGIA: Trinta e oito dentes monorradiculares foram divididos em dois grupos de 19 dentes cada. Os dentes foram preparados através da técnica de coroa-ápice até o instrumento memória #50. Após o preparo, os canais foram radiografados e, então, preenchidos com hidróxido de cálcio. A remoção da pasta no grupo I foi feita com o uso do ultrassom enquanto que no grupo II, a pasta foi removida através da técnica manual. Os dentes foram radiografados novamente para avaliar a remoção do hidróxido de cálcio. As radiografias foram digitalizadas e os terços avaliados de acordo com os níveis de cinza para quantificar a remoção do hidróxido de cálcio. Os testes para amostras independentes e o t de Student (α=0.05) foram aplicados para comparar a remoção da pasta entre os grupos e entre os terços do canal. RESULTADOS: Não houve diferença entre as técnicas ultrassônica e manual para a remoção do hidróxido de cálcio do canal radicular. Não houve diferenças estatísticas na comparação ente os terços avaliados. CONCLUSÃO: Nem a técnica manual nem a ultrassônica removeram completamente o hidróxido de cálcio do canal radicular.

Influence of gutta-percha cone disinfection on leakage: comparison of two sealability assessment methodologies

Aim: To clarify the influence of 5.25% sodium hypochlorite disinfection of gutta-percha cones onleakage and to compare the outcomes of two sealability assessment methodologies (fluid filtrationand dye penetration methods). Methods: Thirty teeth were prepared and filled using the guttaperchalateral condensation technique. Group I was filled with gutta-percha cones disinfectedwith sodium hypochlorite 5.25%, while Group II was filled with cones that were not disinfected.Apical leakage was measured using: (a) fluid filtration technique and (b) linear measurement ofdye penetration after clearance. Results: The Student’s t-test showed no significant differencebetween the groups for both techniques (p<0.05). Conclusions: Both methodologies employed,even with the inherent limitations, were capable of identifying sealing failures. The disinfection ofgutta-percha cones with 5.25% sodium hypochlorite did not alter apical leakage.

Biocompatibility of RealSeal, its primer and AH Plus implanted in subcutaneous connective tissue of rats

OBJECTIVE: This study tested rat connective tissue response to RealSeal, RealSeal primer or AH Plus after 7, 15, 30, 60 and 90 days of implantation. MATERIAL AND METHODS: Thirty Wistar rats had subcutaneous sockets created on their back and received four implants each of polyethylene tubes containing one of the materials tested according to the groups: AH (AH Plus Sealer); RS (RealSeal Sealer); RP (RealSeal Primer); CG (control group - empty tube). After histological processing, sections were analyzed to identify the presence of neutrophils, lymphocytes and plasma cells, eosinophils, macrophages and giant cells, as well as fibrous capsule and abscesses, by an examiner using light microscope. Kruskal-Wallis and multiple-comparisons test were used for statistical analysis. Significance level was set at 5 percent. RESULTS: Lymphoplasmacytic infiltrate scores significantly higher than those of the control group were observed at 14 and 60 days in AH group, and at 90 days in RS group (p<0.05). There were no differences in terms of presence of macrophages, giant cells, eosinophils, neutrophils or fibrosis. AH Plus group scored higher for abscesses at 7 days than after any other period (p=0.031). RP group scored higher for lymphoplasmacytic infiltrate at 14 days than at 90 days (p=0.04). CONCLUSION: The main contribution of this study was to demonstrate that issues involved with tissue tolerance of a Resilon-containing sealer, RealSeal Sealer, cannot be attributed to its primer content.

Effect of endodontic preflaring on electronic determination of working length / Efeito do pré-alargamento endodôntico na determinação eletrônica do comprimento de trabalho

PURPOSE: To evaluate the effect of preflaring on the electronic measurement of working length in mesiobuccal roots of maxillary molars. METHODS: Thirty roots were embedded in an alginate model. Root canals were irrigated with 2.5 percent sodium hypochlorite, and a size 10 K file was inserted into the canal until the locator indicated that apical constriction had been reached. Then, the cervical portion of each canal was flared using the ProTaper system shaping files, whereupon electronic measurements were carried out again. RESULTS: The Student's t test for paired samples did not reveal statistically significant differences in the measurements obtained for preflared and unflared canals (P<0.05). CONCLUSION: Based on the lack of clinical significant relevance of the comparisons carried out in the present study, it is possible to conclude that electronic working length measurement can be carried out either before or after cervical preparation.

OBJETIVO: Avaliar o efeito do pré-alargamento sobre a medição eletrônica do comprimento de trabalho em raízes mésio-vestibulares de molares superiores. METODOLOGIA: Trinta raízes foram incluídas em um modelo de alginato. Canais radiculares foram irrigados com hipoclorito de sódio a 2,5 por cento, e uma lima de tamanho 10 K foi inserida no canal até onde o localizador indicou que a constrição apical tinha sido alcançada. A porção cervical de cada canal foi alargada usando as limas do sistema ProTaper, quando então as medições eletrônicas foram realizados novamente. RESULTADOS: O teste t de Student para amostras pareadas não mostrou diferenças estatisticamente significativas nas medições obtidas para canais pré-alargados e não alargados (P<0,05). CONCLUSÃO: Com base na falta de relevância clínica significativa das comparações realizadas no presente estudo, é possível concluir que a medição do comprimento eletrônico de trabalho pode ser realizado antes ou após o preparo cervical.

Endodontic treatment of a 36-mm long upper cuspid: clinical case report / Tratamento endodôntico de canino superior medindo 36 mm de comprimento: relato de um caso clínico

Purpose: To report a clinical case of a 36 mm long upper cuspid submitted to root canal treatment, with emphasis on the alternative technique employed. Case description: A 32 years old, male patient had suffered subluxation of teeth 12 and 13 and coronal fracture involving enamel and dentin, as well as pulp exposition, of tooth 14 because of a motorcycle accident. The man was given dental assistance and a semi-rigid splinting of teeth numbers 12 and 13 was carried out followed by the root canal treatment in a single visit on tooth no. 14. At 30-day follow-up pulp necrosis was detected in teeth 12 and 13 and the root canal treatment was implemented. The tooth 13 was 36 mm long and since the longest possible file (31 mm) was already in use, the cervical limit of the access cavity was considered as the reference point. Conclusion: This technique not only provided adequate disinfection, preparation and filling of the root canal, but it also allowed preservation of the remaining tooth structure.

Objetivo: Descrever o tratamento endodôntico de um canino superior medindo 36 mm de comprimento, mostrando a técnica empregada no preparo do canal radicular e obturação. Descrição do Caso: Paciente do sexo masculino, com 32 anos de idade, sofreu subluxação dos dentes 12 e 13 e fratura coronária envolvendo esmalte e dentina, com exposição pulpar do dente 14, devido a um acidente de moto. No atendimento de urgência, foi realizada a contenção semirrígida dos dentes 12 e 13, seguida da endodontia em sessão única do dente 14. Trinta dias após, foi diagnosticada necrose pulpar dos dentes 12 e 13 e sua endodontia foi, então, iniciada. O comprimento aparente do dente 13 foi estabelecido em 36 mm e como o instrumento mais longo que dispomos no mercado possui 31 mm, o limite cervical da cavidade de acesso foi usado como bordo de referência. Conclusão: Além de garantir uma correta sanificação, modelagem e obturação do canal, esta técnica também permitiu a preservação da estrutura dental remanescente.

Participação das mulheres na graduação da Faculdade de Odontologia da Universidade Federal do Rio Grande do Sul / Women in school of dentistry, Federal University of Rio Grande do Sul

Introdução: Em 1866, na Universidade de Ohio, graduou-se a primeira mulher da história da Odontologia. A inserção da mulher na Odontologia ocorreu de forma lenta e gradual, acompanhando o desenvolvimento histórico e cultural da sociedade. Um dos fatores que faz com que a mulher opte pela carreira odontológica é o fato de poder exercer o trabalho de forma autônoma. Objetivo: Conhecer o crescimento da participação da mulher na Faculdade de Odontologia da Universidade Federal do Rio Grande do Sul (FO-UFRGS). Materiais e Métodos: Foram analisados os documentos que continham todos os formandos da FO-UFRGS do período de 1900-2010. Resultados: Em 1904, graduaram-se as três primeiras estudantes femininas. No inicio da década de 60, verificou-se um aumento crescente na participação da mulher atingindo taxa de 45%. No ano de 2010, as mulheres constituem 68% dos acadêmicos da Faculdade. Conclusões: Podemos concluir que a mulher iniciou cedo sua participação na Odontologia gaúcha. Deste período até os nossos dias tem havido um paulatino aumento desta participação, culminando com o seu predomínio numérico em relação ao sexo masculino.

Introduction: In 1866, in the University of Ohio graduated the first woman in the history of Dentistry, The inclusion of women in dentistry has occurred slowly and gradually, following the historical and cultural development of society. One factor that makes women choose the dental career is being able to perform the work autonomously. Objective: Knowing the growth of women's participation in the Faculty of Dentistry, Federal University of Rio Grande do Sul (UFRGS-FO). Materials and Methods: The documents that contained all of the graduates of FO-UFRGS, in the period between 1900 and 2010, were analyzed. Results: In 1904, graduated the first three female students. In the early 60s, there was a steady increase in women's participation rate reached 45%. In 2010, women constitute 68% of the students of the Faculty. Conclusions: We conclude that the woman started early on their participation in dentistry in the State. From this period until the present day there has been a gradual increase in this participation, culminating in their numerical predominance in relation to males.

Apical internal inflammatory root resorption and open apex treated with MTA: a case report / Reabsorção apical inflamatória interna e ápice aberto tratado com MTA: relato de caso

Purpose: Internal inflammatory root resorption is a rare condition, characterized by progressive loss of tooth substance which starts on the root canal wall. Usually the process is asymptomatic and diagnosed upon routine radiographic examination. The following report shows the treatment of a case of periapical lesion and apical internal resorption that reached the external root surface. Case description: A 16 year-old male was referred for a routine dental treatment for oral rehabilitation. Radiographic examination showed a resorptive lesion in the apical third and periapical lesion on tooth 21. Crown down preparation was performed and calcium hydroxide was placed for 2 weeks. An apical plug with white MTA was condensed into the resorption cavity and then the canal was obturated with gutta-percha and AH Plus sealer. The follow-up radiographs showed satisfactory resolution. Conclusion: This report showed the results of the treatment with MTA apical plug. The technique avoided an invasive procedure and presented some advantages, like materials biological properties and capable of sealing.

Objetivo: A reabsorção radicular interna inflamatória é uma condição rara caracterizada por progressiva perda de substância dentária, que se inicia nas paredes do canal radicular. Geralmente o processo é assintomático e diagnosticado em exame radiográfico de rotina. O presente relato de caso mostra o tratamento de um caso de lesão periapical e reabsorção interna apical que atingiu a superfície radicular externa. Descrição do caso: Um paciente do sexo masculino de 16 anos foi encaminhado para tratamento odontológico de rotina para reabilitação oral. O exame radiográfico mostrou uma lesão de reabsorção no terço apical e lesão periapical no dente 21. O preparo coronário foi realizado e hidróxido de cálcio foi colocado por duas semanas. Um tampão com MTA branco foi condensado na cavidade da reabsorção e então o canal foi obturado com guta-percha e cimento AH Plus. As radiografias de acompanhamento mostraram resolução satisfatória. Conclusão: Este caso mostrou os resultados do tratamento com tampão apical de MTA. A técnica evitou um procedimento invasivo e apresentou algumas vantagens, tais como propriedades biológicas dos materiais e capacidade de selamento.