Morfología interna del primer molar mandibular permanente. Influencia del uso de ultrasonidos y del microscopio operatorio en la localización de conductosXIV Premio Científico Anual Prof. Dr. D. Pedro Ruiz de Temiño Malo

Abstract

Introduction: Recent studies reflect the existence of accesory canals in the roots of the first lower permanent molars. The main objective of this paper is to determine the influence that the use of ultrasonic tips and the operating microscope have in locating these canals. As a secondary objective, we have used the clearing technique in an innovative way to visualize the actual anatomy of the treated lower molars. Methodology: The access cavities of 53 first lower permanent molars were done in different phases, noting the number of canals located in each of them. The first, without magnification or ultrasound. next the ultrasonic tips were incorporated and, in a third phase, the operating microscope was added. Finally, The technique described by Robertson was used to make the teeth transparent and describe their root canal systems by means of the Vertucci's classification, modified by various authors. Results: Both the use of ultrasound and the operating microscope increased the number of located canals, but the differences were only statistically significant with the simultaneous use of both. Their help was more important in the mesial root than in the distal. We found 26.4% of the mesial roots presented three entry orificies in the pulp chamber, whose configurations towards the apical area were variable. After clearing the samples, 23.1% presented 5 canals. Conclusions: The use of operating microscope and ultrasound is important for locating accessory canals in the lower first molars. The incidence of the mesiocentral canal was 26.4%. The clearing technique should be preceded by a modified access cavity under magnification.