Abstract The mandibular first molar usually has a mesial root with two root canals and a distal root with one or two root canals. However, variations in this morphology, such as multiple root canals, may occur. A 20-year-old male patient presented with a chief complaint of pain and swelling in the left mandibular region. Based on clinical and radiographic exams, the diagnosis of symptomatic apical periodontitis was established. Initially, two root canals in the mesial root and two in the distal root of tooth #36 were located and negotiated using a dental operating microscope. After further exploration, two more root canals were located in the mesial root. The six root canals were prepared. For the final rinse, the irrigant solutions were agitated with an ultrasonic tip. Calcium hydroxide dressing was used, and one month later, the patient presented without signs or symptoms. The root canal filling was performed using the single-cone technique with gutta-percha cones and bioceramic endodontic sealer. At the 12-month follow-up, a periapical radiograph showed bone repair in the periradicular region. Four root canals in the mesial root of the mandibular first molar represent a rare configuration. The clinician must consider possible anatomical variations of the root canal system and carefully analyze the imaging exams along with clinical observation during treatment so that all canals are located and treated to achieve success.

Resumo O primeiro molar inferior geralmente apresenta uma raiz mesial com dois canais radiculares e uma raiz distal com um ou dois canais radiculares. No entanto, podem ocorrer variações nessa morfologia, como a presença de múltiplos canais radiculares. Um paciente do sexo masculino, de 20 anos, apresentou-se com uma queixa principal de dor e edema na região mandibular esquerda. Com base em exames clínicos e radiográficos, foi estabelecido o diagnóstico de periodontite apical sintomática. Inicialmente, dois canais radiculares na raiz mesial e dois na raiz distal do dente #36 foram localizados e negociados sob um microscópio operatório. Após exploração adicional, mais dois canais radiculares foram localizados na raiz mesial. Os seis canais radiculares foram preparados e, para a irrigação final, as soluções irrigadoras foram agitadas utilizando um instrumento ultrassónico. Foi feito um curativo com pasta de hidróxido de cálcio e, um mês depois, o paciente apresentou-se sem sinais ou sintomas. A obturação do canal radicular foi realizada utilizando a técnica de cone único, com cones de guta-percha e cimento endodôntico biocerâmico. Passados 12 meses, foi feita uma radiografia periapical, que mostrou reparo ósseo na região perirradicular. A presença de quatro canais radiculares na raiz mesial do primeiro molar inferior é uma configuração rara. Possíveis variações anatómicas no sistema de canais radiculares devem ser consideradas pelo profissional, que deve analisar criteriosamente os exames de imagem, além da observação clínica durante o tratamento, para que todos os canais sejam localizados e tratados para alcançar o sucesso.

Resumo Os caninos inferiores geralmente possuem uma raiz com um canal radicular. No entanto, este grupo dentário pode ter variações. O presente estudo relata dois casos de retratamento endodôntico com sucesso de dois caninos inferiores com duas raízes e dois canais radiculares, uma configuração mais rara. Em ambos os casos relatados, o insucesso do tratamento na intervenção endodôntica primária foi devido à não localização do canal radicular lingual, que foi visualizado quando as radiografias periapicais foram feitas com uma angulação mesial. Canais não localizados durante o tratamento endodôntico podem levar à periodontite apical, por isso é importante realizar radiografias em diferentes angulações, avaliar o pavimento da câmara pulpar e considerar as variações da morfologia radicular. Após a realização da cavidade de acesso e observação de um istmo em ambos os casos, os canais linguais foram localizados e instrumentados. Foi utilizada medicação de hidróxido de cálcio entre as consultas e os canais foram obturados com diferentes cimentos nos casos relatados (à base de resina epóxi e biocerâmico). O acompanhamento radiográfico realizado após 18 meses no primeiro caso e 5 meses no segundo caso sugeriu normalidade dos tecidos periapicais. É essencial seguir estratégias para tratar a complexidade do sistema de canais radiculares durante a limpeza, modelagem, desinfeção e obturação do canal para controlar a infeção e alcançar um resultado bem-sucedido do tratamento endodôntico.

Abstract Mandibular canines usually have one root with one root canal. However, variations may occur. The present study reports two cases of successful retreatment of two mandibular canines with two roots and two root canals, a rarer configuration. In both cases reported the unsuccessful treatment in the primary endodontic intervention was due to overlooking the lingual root canals, which were identified when periapical radiographs were taken at a mesial angle. Because canals missed during endodontic therapy may lead to periapical periodontitis, it is important to take radiographs from different angles, analyze the pulp chamber floor, and consider the variations in root canal morphologies. After performing the access cavity and observing an isthmus in both cases, the lingual root canals were located and instrumented. Calcium hydroxide dressing was used between appointments, and the root canals were filled with different sealers in each case (epoxy resin-based and bioceramic sealers). The follow-up X-rays taken 18 months later in the first case and 5 months later in the second case suggested normality of the periapical tissues. It is essential to use strategies that enable reaching the whole complexity of the root canal system during the canal cleaning, shaping, disinfection, and filling procedures in order to control the infection and achieve a successful endodontic treatment outcome.

The objective of this study was to describe a new method for the quantitative analysis of a microleakage of endodontic filling materials. Forty extracted single-rooted teeth were randomly divided into three experimental groups. After root canal shaping, the experimental groups were filled using the lateral condensation technique with the Epiphany system (G1), with gutta-percha + Sealapex (G2), and with gutta-percha + AH Plus (G3). Each root was mounted on a modified leakage testing device, and caffeine solution was used as a tracer (2000 ng mL-1, pH 6.0), applied in the coronal direction towards the tooth apex, creating a hydrostatic pressure of 2.55 kPa. Presence of caffeine in the receiving solution was measured after 10, 30, and 60 days, using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). None of the groups presented microleakage at 10 days. At 30 days, G2 and G3 showed similar infiltration patterns (means: 16.0 and 13.9 ng mL-1, respectively), whereas G1 showed significantly higher values (mean: 105.2 ng mL-1). At 60 days, leakage values were 182.6 ng mL-1for G1, 139.0 ng mL-1 for G2, and 53.5 ng mL-1 for G3. AH Plus showed the best sealing ability and HPLC-MS/MS showed high sensitivity and specificity for tracer quantification.

The aim of this study was to evaluate the penetration of a resin/polyester polymer-based material (Resilon Real Seal; SybronEndo Corp., Orange, USA) into simulated lateral canals, and the quality of obturations by different techniques. A total of 30 standardized simulated canals were divided into three groups according to the technique of obturation used: MS (McSpadden), SB (SystemB/Obtura II), and LC (Lateral Condensation). To analyze the penetration of the filling material, the simulated canals were digitalized and the images were analyzed using the Leica QWIN Pro v2.3 software. The data of the middle and apical thirds were separately submitted to analysis of variance (ANOVA), followed by the Tukey’s test for the comparison of the techniques. Results showed a significant difference (p < 0.05) between groups (LC < SB) in the middle third, and a significant difference (p < 0.05) between groups (LC < SB and MS < SB) in the apical third. To analyze the quality of the obturations, the canals were radiographed and evaluated by three examiners. The Kappa test on interexaminer agreement and the nonparametric Kruskal-Wallis test indicated no significant difference between filling techniques. It was concluded that Resilon achieves greater levels of penetration when associated with thermoplastic obturation techniques.

The aim of this study was to evaluate the quality of filling in main and lateral root canals performed with the McSpadden technique, regarding the time spent on the procedure and the type of gutta-percha employed. Fifty simulated root canals, made with six lateral canals placed two apiece in the cervical, middle and apical thirds of the root, were divided into 5 groups. Group A: McSpadden technique with conventional gutta-percha, performed with sufficient time for canal filling; Group B: McSpadden technique with conventional gutta-percha, performed in twice the mean time used in Group A; Group C: McSpadden technique with TP gutta-percha, performed with sufficient time for canal filling; Group D: McSpadden technique with TP gutta-percha, performed in twice the mean time used in Group C; Group E: lateral condensation technique. Images of the filled root canals were taken using a stereomicroscope and analyzed using the Leica QWIN Pro software for filling material flow, gutta-percha filling extension and sealer flow. Data were analyzed by analysis of variance (ANOVA) and Tukey test (p < 0.05). The best values of penetration in lateral canals in the middle third occurred in the groups where TP gutta-percha was used. However, in the apical third, group B showed the best values. Although a longer time of compactor use allows greater penetration of the filling material into the lateral canals, the presence of voids resulted in bad quality radiographic images, suggesting porosity. The best quality of filling material was observed in Group A (McSpadden technique with conventional Gutta-Percha, performed with sufficient time for root canal filling).