Scanning electron microscopy of fluoride-induced disturbances on the enamel surface of rat molars.

Rats were given a single high dose of fluoride at the age of 5 days and killed after 24 h, 10 or 15 days. The maxillary first molars were prepared for scanning electron microscopic examination. It was concluded that a single dose of fluoride, preferentially affecting ameloblasts with a high secretory activity, leads to the formation of subameloblastic cysts and enamel hypoplasias covered with granular deposits.