Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Zinc concentration in outer enamel. Layers relate to successive biopsies, each deeper than the previous34. The apparent increase in layer 1 relatively soon after eruption, in subjects less than 20 years old, was absent in subjects aged 30-49 years old.
