CHEMICAL AND PHYSICAL STUDIES OF ENAMEL FROM HUMAN TEETH

III. SPECIFIC GRAVITY, NITROGEN CONTENT, AND HISTOLOGIC CHARACTERISTICS OF OPAQUE WHITE ENAMEL

¹ Department of Anatomy and Division of Dental Research, University of Rochester, School of Medicine and Dentistry, Rochester, N. Y.

1. A study has been conducted to characterize the white opaque enamel as to histologic structure, density, and nitrogen content.

2. On the basis of clinical location and gross appearance, two types of opaque enamel were studied: (a) white spot areas indicative of early carious lesions, and (b) hypocalcified developmentally defective areas.

3. Microscopic observation of ground sections from white spot areas and teeth with developmentally defective areas indicated a similarity of the histologic structure in both varieties of white opaque enamel. The main exception was that, in the latter, the zone of consolidation was absent.

4. The density and nitrogen determination of opaque enamel suggest that both types have higher nitrogen content and lower density than the adjacent sound enamel.