Abstract This study aimed to analyze the root and root canal morphology of mandibular first and second molars using CBCT images. A total of 2,400 mandibular molars exams were selected from 600 patients aged between 18 and 75 years. The number of roots, number of root canals, and root canal configuration according to the Vertucci classification were verified. Overall, 94.92% of mandibular first molars and 90.17% of mandibular second molars had two separate roots. Among the biradicular molars, the first molars showed a greater incidence of type IV canals in the mesial root and type I in the distal root. In the second molars, the most common canal form was type IV in the mesial root and type I in the distal root. In the triradicular molars, the type IV and type I configurations were the most common in the mesial root of the first molar and second molar, respectively. In both triradicular molars, there was a prevalence of type I canal in the distal and DL roots. Statistical analysis was performed at a significance level of 0.05. The number of roots was correlated with gender (Spearman test), and the canal's configuration with gender and bilaterality (Wilcoxon test). The subpopulation studied has a high incidence of bilateral symmetry and mandibular molars with two roots with two distinct mesial canals and one distal canal. The bilateral configuration is possible to estimate the number of canals, especially in images that are difficult to visualize, such as atresic canals.

No presente estudo foi avaliado in vitro, o efeito da aplicação das soluções quelantes EDTA, EGTA, e CDTA sobre a dentina humana na adesividade e infiltração apical dos seguintes cimentos obturadores dos canais radiculares: Sealer 26, Sealapex, N-Rickert, e Endofill. Bem como observar se existe correlação matemática entre os testes de adesividade e infiltração marginal apical. Foram utilizados 80 dentes molares superiores e inferiores para o teste de adesividade, que tiveram suas coroas desgastadas na face oclusal até obter uma superfície de dentina plana onde o cimento era depositado com auxílio de um cilindro de alumínio (10 mm x 6 mm). O teste de adesividade foi realizado através da máquina universal de ensaio Instron 4444. O teste de infiltração marginal apical utilizou 160 caninos superiores, que após a instrumentação e obturação dos canais radiculares foram submetidos ao processo de diafanização para a visualização do nível de infiltração marginal apical. A penetração do nanquim na região apical foi medida através do microscópio de mensuração. Os dentes foram divididos em 4 grupos: grupo 1, água destilada; grupo 2, EDTA, grupo 3, EGTA; grupo 4, CDTA. Os resultados evidenciaram diferença estatística (p<0.01) entre os cimentos e soluções testadas e não evidenciaram correlação matemática entre os testes de adesividade e infiltração marginal. O cimento Sealer 26 e a solução de EDTA apresentaram os melhores resultados para os testes de adesividade e infiltração marginal apical.

The effect of chelating solutions EDTA, EGTA and CDTA on human dentin adhesiveness and microleakage with 4 sealers (Sealer 26, Sealapex, N-Rickert and Endofill) was evaluated in vitro. Whether or not there was a mathematical correlation between the tests of adhesiveness and microleakage was also evaluated. A total of eighty maxillary and mandibular molars were used to test adhesiveness. After wearing of the occlusal surface to obtain a flat surface, the sealer was placed with an aluminum cylinder (10 mm x 6 mm). Adhesiveness was evaluated with a 4444 Instron universal testing machine. Microleakage was evaluated in 160 maxillary canines after root canal instrumentation, obturation and clearing. The penetration of India ink in the apical region was measured with a measurescope. The teeth were divided into 4 groups: group 1, distilled water; group 2, EDTA; group 3, EGTA; group 4, CDTA. Sealer 26 and EDTA had the best results (p<0.01) for adhesiveness and microleakage. There was no correlation between the test for adhesiveness and microleakage.