Electron Microscopy of Enamel and Dentin of Teeth of the Odontaspis (Selachii)

¹ Departamento de Histologia, Faculdade de Farmacia e Odontologia, University of São Paulo, and Secção de Microscopia Electrônica, Escola Politécnica, University of São Paulo, São Paulo, Brazil

The present study of transverse, longitudinal, and external surface sections made with the aid of positive replicas of the teeth of the shark Odontaspis yielded the following results concerning the ultrastructure of shark enamel and dentin:

1. The general morphology of the ultrastructure of shark teeth appeared to be similar to that of human teeth as far as it was observed.

2. The ultrastructure of the substance covering the shark dentin was morphologically similar to human enamel. This substance was composed of a crystalline component identified as natural apatite¹⁵ and prismlike configurations, whose general arrangement and shape were similar to those of the human. These observations were offered as evidence in support of the belief that the external revestment of the shark teeth is a true enamel.

3. The shark dentin was seen to be composed of canals, thin-walled fibers, structureless fibers, and a matrix. The disposition of the canals was irregular in comparison with human dentin canals. The shark dentin canal, as in the human, presented in its interior a fiber which is believed to be the dentin fiber. Throughout the dentin matrix, structureless fibers were observed which concentrated in regions where the rows of the canals are disposed.

This article has been cited by other articles:

				M. L. Moss, S. J. Jones, and K. A. Piez Calcified Ectodermal Collagens of Shark Tooth Enamel and Teleost Scale Science, August 28, 1964; 145(3635): 940 - 942. [Abstract] [PDF]