A quantitative and diametral analysis of human dentinal tubules at pulp chamber ceiling and floor under scanning electron microscopy.

The purposes of this study are (i) to evaluate and compare the dentinal tubule density, tubule diameter and percentage area of dentin occupied by tubules at the pulp chamber ceiling and floor; and (ii) to evaluate the effects of age on the number and dimensions of tubule openings. Twelve intact, human mandibular third molars were recruited. Six teeth belonged to patients up to 30 years of age and six teeth belonged to patients over 50 years. Scanning electron microscopic evaluations were made at two different locations: the pulp chamber ceiling and floor. The pulp chamber ceiling presented higher tubule density (P < 0.0001) and greater percentage area of dentin occupied by tubule openings (P < 0.0001) compared to the pulp chamber floor. Also, younger age group had greater tubule diameter (P < 0.0001), higher tubule density (P < 0.0001) and greater percentage area of dentin occupied by tubule openings (P < 0.0001) compared to older age group. Pulp chamber ceiling presents higher tubule density and greater area of exposed tubules. In younger people, the pulp chamber floor presents considerably high tubule diameter. The number and dimensions of dentinal tubule openings significantly decrease with age.