Studies on the Physical Properties of Rodent Enamel

Abstract

A method was devised for the detn. of density distribution of small amts. (80 mg.) of powdered calcified tissues. It employed a modified Manly-Hodge separation tube in which successive fractionation of the same sample was performed at different densities. Albino rat molar enamel had a density between 2.72 and 2.92 g./cc. with a single maximum in the region of 2.9. The distribution was somewhat different from that reported for human deciduous and permanent enamel. X-ray powder diffraction analysis demonstrated that the mineral salt in rodent molar enamel closely resembles hydroxylapatite. As a consequence of this, density differences between rat and human tissues were attributed to a relatively greater amt. of organic material in rat enamel.