ODONTOBLASTS AND DENTINOGENESIS

(A HISTOCHEMICAL STUDY)

¹ Departments of Anatomy, College of Dentistry and The Graduate School of Arts and Sciences, New York University, New York, N. Y.

1. During the differentiation of the odontoblast, alkaline phosphatase comes to be localized within the nucleus, cytoplasm and the dentinal fibril just before and during the early calcification of dentin.

2. In older dentin, this same situation holds true and in addition, Tomes' dentinal fibril is also strongly phosphatase positive.

3. On the basis of the well known function of phosphatase in connection with normal calcification, we can now state with a fair degree of certainty that the function of the odontoblast and Tomes' fibril is to a great extent biochemical—to produce and mediate phosphatase transfer which in turn leads to the splitting of phosphate in the very region in which we know it is deposited.