A scanning electron microscopic evaluation of human dentinal tubules according to age and location

Abstract

A scanning electron microscopic examination of human dentinal tubules was done according to the age of the subject and specific area of the tooth from which the specimen was obtained. Teeth from the following five age groups were examined: 20 to 34, 35 to 44, 45 to 54, 55 to 79, and 80 and above; while the specific tooth locations examined were: the apical, middle, and cervical root dentin and the coronal dentin. The results showed that the number of dentinal tubules decreased with increasing age (e.g. the mean number of tubules=242,775 for age group 20 to 34; 149,025 for age group 80 and above), and apical location (e.g. the mean number of tubules=265,460 for coronal dentin; 49,140 for apical root dentin). Both of these findings were statistically significant (p<0.01). These results may account for the marked sensitivity and increased bacterial penetration of coronal dentin when compared with the minimal bacterial and irritant penetration of apical dentin.