Comparative study of tubular diameter and quantity for human and bovine dentin at different depths.

This study compared the tubular dimensions and distribution of human and bovine dentin. Ten human molars and 10 bovine incisors were ground with a high-speed handpiece to obtain 3 sections at different dentin depths (superficial, middle and deep). The specimens were sputter-coated with gold to be examined under scanning electron microscopy (SEM). Three SEM micrographs were recorded randomly for each dentin depth. The number of tubules was counted and the diameter of 5 tubules selected at random was measured in each SEM micrograph. Data were analyzed statistically by ANOVA and Tukey's test (alpha=0.05). In bovine teeth, superficial dentin (4.21 microm) and middle dentin (3.98 microm) had a significantly greater (p<0.05) diameter than deep dentin (3.14 microm) tubules. In human teeth, superficial dentin tubule diameter (2.42 microm) was significantly smaller (p<0.05) than deep dentin (2.99 microm) and middle dentin (2.94 microm) tubule diameters, which did not differ significantly from each other (p>0.05). The number of tubules per square millimeter, regardless of the region, was significantly greater in human dentin (22,329) than in bovine dentin (15,964). There was a clear difference in tubule structure and morphology between human and bovine dentin.