Aim: To evaluate dentin tubule numerical density variations below the CEJ.
Methodology: Three human non-carious permanent canines were sectioned parallel to the CEJ to obtain dentin disks 1mm thick whose surfaces were 1mm and 2mm below the CEJ. Each disk was sectioned into quarters resulting in four segment locations: facial, lingual, mesial, and distal. The outer (PDL side) and inner (pulp side) surfaces of the specimens were shaped to expose dentin with SiC papers and polished. Numerical tubule density was determined from SEM images. All data were statistically analyzed using a three-way ANOVA.
Results: The dentin tubule density (number/mm(2)) ranged from 13,700 to 32,300. Dentin tubule density was relatively uniform at 1mm and 2mm below the CEJ and increased by a factor of about two from the outer to the inner surface, which was significantly different (P<0.0001).
Conclusions: The tubule density variations at the cervical root did not present marked.