Aging of tissues of the roots of nonfunctional human teeth (impacted canines).

In order to examine the aging of dentin and cementum, seventy-two impacted human canines, nonfunctional and not affected by external factors, such as attrition, abrasion, caries, etc., were surgically extracted. Ground sections were prepared and the areas of sclerotic dentin and cementum were measured with the aid of a planimeter and expressed as a percentage of the total root area. It was found that there is a significant increase in sclerotic dentin and apposition of cementum with an increase in age.