[Quantitative study of the mineral substance of the human dental cementum].

A study of the mineral substance of human dental cementum was made by various biophysical methods. In healthy teeth, average degree of mineralization of the cementum as well as crystallinity and fluoride content of its mineral substance, were found to increase as a function of age. This evolution, typical of the physiological ageing process of calcified tissues, is especially pronounced for the cementum, because of the absence of remodeling activity such as that occuring in bone tissue. Cementum of impacted or semi-impacted teeth was found to have a significantly lower degree of mineralization than that of sound teeth in occlusion. In periodontally diseased teeth, the increase in crystallinity and degree of mineralization of the cementum as a function of age is considerably greater than that observed in healthy teeth. These changes were found to affect the cervical cement first of all, and progressively, the entire tissue. No difference was observed, however, in the fluoride content of the cement of periodontally diseased teeth and healthy teeth of the same age.