Methods: Ten human molars and ten bovine incisors were grounded with a hand-piece turbine to obtain three degree of dentin proof (superficial, median and deep). The samples were coated with gold in a sputtering machine to be observed in SEM (JEOL-JSM5600LV). Three photomicrographs were aleatory taken for each dentin proof, the number of tubules was counted and 5 aleatory tubules had the diameter measured for each photomicrography. The results were submitted to analysis of variance and Tukey's test (5%).
Results: The bovine superficial dentin tubules (4.21 µm) showed statistical significant difference with higher diameter than median dentin (3.98 µm) and deep dentin (3.21 µm). The human deep dentin tubules (2.99 µm) showed statistical significant difference with higher diameter than median dentin (2.94 µm) and superficial dentin (2.42 µm). The number of tubules per mm2, independent of region, was statistical significant difference with higher means for human dentin (22,329) than bovine dentin (15,964).
Conclusions: The tubular structure, independent of region, was different between human and bovine dentins in relation to both diameter and quantity of the tubules.