THE DISTRIBUTION OF NITROGEN IN HUMAN ENAMEL

¹ Eastman Dental Dispensary, Rochester, N. Y.

1. There is a definite nitrogen distribution pattern throughout all dental enamel, with the greatest amounts of nitrogen at the surface and dentinoenamel junction.

2. There appears to be a difference in nitrogen distribution of permanent teeth with relation to age. In the over 50 age group, the nitrogen content of the surface and junction enamel is comparatively higher and the minimal enamel nitrogen content occurs at a greater enamel depth than in younger teeth.

3. No significant difference occurs in the total nitrogen content of enamel of permanent teeth with advancing age.

4. Deciduous enamel contains more nitrogen than permanent enamel.

5. Carious enamel contains approximately twice as much nitrogen as noncarious enamel on a per cent/weight basis.