On the Vitality of Dental Enamel.

Abstract

Various common pathological changes in the dental enamel of fully erupted human teeth, which destroy its protective function, are ascribed by some investigators to intrinsic nutritional alterations, rather than to extrinsic influences. The proof that enamel contains protein 1 , 2 has induced several investigators to regard its presence as indicative of nutritional capacity, despite the fact that, although permeable to water and various substances, enamel completely lacks power of self-repair after injury and has no cellular nuclei. That the contained protein (probably keratin) is not associated with intrinsic nutritional changes in the enamel of erupted teeth is indicated by the writer's further observation that conventional tests for proteolytic and amylolytic enzymes, applied to extracts of pulverized normal enamel, were completely negative. These tests, to be extended, will include studies of abnormal enamel.