Anatomical evaluation of the root canal diameter and root thickness on the apical third of mesial roots of molars

Abstract

The purpose was to determine the diameter of the main root canal and wall thickness in the apical dentin in mesial roots of maxillary and mandibular molars. Forty mesiobuccal and mesial root specimens were sectioned horizontally at 1, 2 and 3mm from the apex, and measured at each top surface by using optical microscopy to an accuracy of ×20 magnification. The anatomical parameters were established as the following points of reference: AB, two points connected by a line from the outer edge of the mesial wall to the outer edge of the distal one through the center of the root canal to measure the thickness of the root and mesiodistal diameter of the root canal (CD). A second line (EF) was designed to evaluate the diameter of the root canal in the buccolingual direction. All data were summarized, and values were assessed statistically by ANOVA and Bonferroni multiple comparisons. The buccolingual (BL) root canal diameters at 1, 2 and 3mm in the mandibular and maxillary molars were greater than in the mesiodistal (MD), showing statistically significant differences (p<0.05). The MD root thicknesses at 1, 2 and 3mm in mandibular and maxillary molars were statistically significant (p<0.05). The lowest value to 1mm from the apex in the mandibular molars was 1.219mm and the highest at 3mm from the root apex in maxillary molars was 1.741mm. The BL diameters in maxillary and mandibular molars were higher than the MD diameter. The thickness (MD) of maxillary and mandibular molars decreased as a function of apical proximity.