STUDIES ON THE DISTRIBUTION OF RADIOACTIVE PHOSPHORUS IN THE TOOTH ENAMEL OF EXPERIMENTAL ANIMALS

Abstract

Radio phosphorus (P32) was detected in the enamel of fully formed teeth of 9 cats, 5 dogs and 1 monkey at from 4 hrs. to 9 days following the adm. of the radioactive isotope. The relatively greatest radioactivity was recorded in the surface layer and high density fraction of the enamel. This relation was reversed when the dentition was covered and salivary secretion excluded from the tooth surfaces. The enamel of unerupted, actively calcifying monkey teeth showed a thirty times greater P32 exchange than fully erupted teeth of the same animal. Freshly extracted human teeth showed a marked activity in the surface enamel after having been in contact with saliva containing radioactive phosphorus. The enamel is subject to a mineral exchange, partly through the blood supply of the teeth, and partly through contact between the enamel surface and the oral secretions.