Molares superiores apresentam morfologias radiculares e canais radiculares variáveis. Este relato de caso descreve o manejo endodôntico de dois casos de canais mésio-centrais (MC) encontrados em molares superiores. Canais MC estavam presente em um primeiro molar superior com uma única raiz vestibular (Caso 1), e em um segundo molar com três raízes vestibulares (Caso 2). Uma avaliação da configuração interna destes dentes foi realizada usando tomografia computadorizada de feixe cônico (TCFC). Ampliação com microscópio operatório odontológico, lupas cirúrgicas e o uso de um explorador endodôntico possibilitaram a identificação dos orifícios dos canais MC. Os canais radiculares dos dois casos foram preparados e obturados. Imagens radiográficas pós-obturação revelaram quatro (um MC, dois mésio-vestibulares e um palatino) e cinco (um MC, dois mésio-vestibulares, um disto-palatino e um palatino) canais radiculares, que foram obturados nos Casos 1 e 2, respectivamente. Configurações complexas de canais em molares superiores, incluindo a presença de canais MC foram apresentadas. TCFC foi uma ferramenta útil no diagnóstico e propiciou uma descrição precisa destas variações anatômicas incomuns.

Maxillary molars present variable root canal and root morphologies. This report describes the endodontic management of two cases of midbuccal canals found in maxillary molars. Midbuccal canals were present in a maxillary first molar with a single buccal root (Case 1), and in a maxillary second molar with three buccal roots (Case 2). An assessment of the internal configuration of these teeth was performed using cone-beam computed tomography (CBCT). Magnification with a dental operating microscope, surgical loupes, and the use of an endodontic explorer enabled the identification of the midbuccal canal orifices. The root canals in both cases were chemomechanically prepared and filled. Postobturation radiographic images revealed four (one midbuccal, two mesiobuccal and one palatal) and five (one midbuccal, two mesiobuccal, one distobuccal and one palatal) root canals, which were filled in Cases 1 and 2, respectively. Complex canal configurations of maxillary molars including the presence of midbuccal canals were presented. CBCT was a valuable tool in this diagnosis, as it provided a precise description of these unusual anatomical variations.

ABSTRACT OBJECTIVE: The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration. MATERIAL AND METHODS: Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPDL were fixed to cylinders with two stainless steel wires. Post-holes were prepared by standardizing the length at 8 mm and root canal impressions were made with self-cured resin acrylic. Cast dowel and core sets were fabricated and luted with Panavia F resin cement. Half of the samples were submitted to ultrasonic vibration before the tensile test. Data were analyzed statistically by two-way ANOVA and Tukey's post-hoc tests (p<0.05). RESULTS: The ultrasonic vibration reduced the tensile strength of the samples directly included in resin cylinders. There was no difference between the values, whether or not ultrasonic vibration was used, when the PDL was simulated. However, the presence of SPDL affected the tensile strength values even when no ultrasonic vibration was applied. CONCLUSION: Simulation of PDL has an effect on both ultrasonic vibration and tensile testing.