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.

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.

Resumo O objetivo deste estudo foi avaliar a biocompatibilidade de cimentos endodônticos experimentais à base de metacrilato contendo fosfato α-tricálcico ou hidroxiapatita nanoestruturada in vitro e in vivo. Cimentos experimentais de cura dual à base de metacrilato com a adição de fosfato de α-tricálcico (α-TCP) ou hidroxiapatita (HAp), a 10% em peso, foram formulados e comparados com AH Plus (AHP). Viabilidade celular foi avaliada por brometo de 3- (4,5-dimetil-tiazoil) -2,5-difenil-tetrazólio (MTT) e sulforodamina B (SRB). Cimentos foram implantados no tecido subcutâneo dos ratos e avaliados histologicamente. Bioatividade foi avaliada pela atividade da enzima fosfatase alcalina (ALP) e Alizarin Red (AR) utilizando células da papila apical (SCAPs) e pela deposição óssea, medida em cavidades cirúrgicas no fêmur de ratos preenchidos com AH Plus e α-TCP. Nos dois ensaios de viabilidade, HAp e AHP não apresentaram diferenças estatísticas, α-TCP apresentou menores resultados de viabilidade para o ensaio MTT (p <0,05). Resultados histológicos mostraram que houve uma diminuição do conteúdo inflamatório de acordo com os períodos, e o AHP foi o único grupo que apresentou células gigantes (período de 7 dias). A condensação das fibras colágenas aumentou conforme os períodos, sem diferenças entre os grupos. Houve aumento da atividade da ALP e deposição de nódulos mineralizados de acordo com os períodos. HAp e α-TCP apresentaram maiores valores para a atividade de ALP em 5 dias e em 5, 10 e 15 dias para AR, com diferença para o AHP (p <0,05). O α-TCP apresentou valores superiores aos 10 e 15 dias quando comparado ao HAp e AHP para AR (p <0,05). Aos 90 dias, α-TCP e controle (cavidade vazia) apresentaram maior deposição de tecido ósseo quando comparado ao AHP (p <0,05). α-TCP e HAp, presentes nos cimentos à base de metacrilato, apresentaram biocompatibilidade e potencial para serem utilizados como seladores endodônticos na prática clínica. Investigações adicionais são necessárias para obter informações sobre as propriedades físico-químicas dessas formulações de cimentos antes de sua implementação clínica.

Abstract This study aimed to evaluate, in vitro and in vivo, the biocompatibility of experimental methacrylate-based endodontic sealers containing α-tricalcium phosphate (α-TCP) or nanostructured hydroxyapatite (HAp). Experimental methacrylate-based dual-cure sealers with the addition of α-TCP or HAp, at 10%wt were formulated and compared to AH Plus (AHP). Cell viability was assessed by 3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT), and sulforhodamine B (SRB). Sealers were implanted in rats’ subcutaneous tissue and histologically evaluated. Bioactivity was assessed by alkaline phosphatase enzyme activity (ALP) and Alizarin Red (AR), using apical papillary cells (SCAPs), and by the bone deposition measured in surgical cavities on rats’ femur filled with AH Plus or α-TCP. In both viability assays, HAp and AHP sealers were similar, and α-TCP presented lower viability compared to the others at MTT assay (p<0.05). A gradual decrease of the inflammatory response according to the periods was observed and AHP was the only that presented giant cells (7-day period). Collagen fibers condensation increased according to the periods, with no differences among sealers. There was an increase at ALP activity and mineralized nodules deposition according to periods. HAp and α-TCP presented higher values for ALP activity at 5 days and at 5, 10, and 15 days for AR and were different from AHP (p<0.05). α-TCP presented superior values at 10 and 15 days compared to HAp and AHP for AR (p<0.05). At 90 days, α-TCP and control (empty cavity) showed high bone deposition compared to AHP (p<0.05). α-TCP and HAp, in a methacrylate-based sealer, presented biocompatibility and bioactivity, with the potential to be used as endodontic sealers in clinical practice. Further investigations are required to gain information on the physicochemical properties of these sealers formulation before its clinical implementation.

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.

Abstract Objectives The aim of this study was to evaluate the influence of surfactants 0.2% or 0.1% cetrimide (Cet) or 0.008% benzalkonium chloride (BAK) on 2.5% calcium hypochlorite (Ca(OCl)2), and compare to sodium hypochlorite (NaOCl), regarding the properties of pH, free chlorine content, surface tension, contact angle, pulp dissolution and antimicrobial activity. Material and Methods The pH and free chlorine content were evaluated by digital pHmeter and by titration, respectively. Surface tension was measured by the platinum ring technique with a Du Noüy tensiometer. The solution's contact angle in human dentin surfaces was checked by Drop Shape Analyzer software. Bovine pulps were used for pulp dissolution analysis and the dissolving capacity was expressed by percent weight loss. Antimicrobial activity over Enterococcus faecalis was evaluated by the agar diffusion method. Results Surfactants addition to Ca(OCl)2 and NaOCl did not alter the pH, free chlorine content and pulp dissolution properties. Ca(OCl)2 had the highest surface tension among all tested solutions. When surfactants were added to Ca(OCl)2 and NaOCl, there was a significant reduction of surface tension and contact angle values. The addition of 0.2% or 0.1% Cet enhanced antimicrobial activity of both Ca(OCl)2 and NaOCl. Conclusion Surfactant addition to 2.5% Ca(OCl)2 has shown acceptable outcomes for pH, free chlorine content, surface tension, contact angle, pulp dissolution and antimicrobial activity. Furthermore, the addition of 0.2% Cet showed better results for all tested properties.

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.

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.

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.

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.

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.

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 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

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.

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.

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.

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%. 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.

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%, 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.

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% 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: 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 dipomos 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.

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: 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.

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.