Fluoride distribution in the facial surfaces of human maxillary central incisors

The fluoride distributions in the incisal, middle and cervical regions of the facial surfaces of six maxillary central incisors were determined by three successive acid etch biopsy procedures. The fluoride concentrations were adjusted to standardized depths of 0--10 micron, 10--20 micron and 20--30 micron. In the biopsy areas the enamel fluoride concentrations decreased with increasing depth. In all the teeth the fluoride content was lowest in the incisal region and highest at the cervical third.