FLUORIDE UPTAKE BY PROXIMAL SURFACES FROM PROFESSIONALLY APPLIED FLUORIDES - AN IN-VITRO STUDY

This study was performed to examine the uptake of fluoride by mesial e namel surfaces of extracted teeth from different types of topical fluo ride. Forty-eight extracted human molars and twelve premolars were ran domly divided into four groups and mounted in twelve wax blocks with f ive teeth in proximal contact in each block. Each group was treated fo r four minutes with either 1.23 percent acidulated phosphofluoride con ventional gel, thixotropic gel, or foam in lined trays, or 2 percent n eutral sodium fluoride solution applied with a cotton tip applicator. Acid-etch biopsies were performed three times to indicate the amount o f fluoride uptake at three different depths. The results demonstrated that there was a statistically significant increase in fluoride uptake in the surface layer with both gels and foam (1150, 1058 and 1120 ppm F), whereas there was an insignificant increase with the fluoride sol ution (27 ppm F). In the deepest layer, the thixotropic fluoride produ ced the greatest fluoride uptake (919 ppm F) in comparison with the up take from conventional gel (383 ppm F), foam (297 ppm F), or solution (118 ppm F).