Density and diameter of dentinal tubules of first and second primary human molars - comparative scanning electron microscopy study
Henrique Castillhos Ruschel / Orlando Chevitarese

The aim of the present survey was to evaluate tubule density and diameter of dentin of first and second primary human molars and compare the two dental categories. These evaluations were done solely at the middle third of the crowns of twenty extracted noncarious teeth separated in two groups (first molars and second molars). The tubule diameters observed were 0.794µm and 1.0µm for first and second molars, respectively (measurements done at 35-65% from the pulp-chamber walls). Regarding tubular density, the measurements indicated 17,997.594 tubules/mm2 and 25,211.317 tubules/mm2 for first and second molars, respectively. Comparisons between-groups indicated that tubule diameter and density of dentin were higher in second molars, being the difference highly significant (P<0.01).