The Protective Effect of TiF sub(4), SnF sub(2) and NaF on Erosion of Enamel by Hydrochloric Acid in vitro Measured by White Light Interferometry

The purpose of this in vitro study was to compare the protective effect of TiF sub(4), SnF sub(2) and NaF (all 0.5 M F) on the development of erosion-like lesions in human dental enamel. Four enamel specimens from each of 6 extracted molars were polished and embedded in epoxy resin. The enamel surfaces of 3 specimens from each tooth were treated with the different fluoride solutions for 2 min. Following fluoride treatments, the specimens were immersed in 0.01 M HCl (pH 2.0), for 2, 4 and 6 min in order to mimic a gastric reflux situation. One specimen from each tooth was used as a control and was only exposed to acid. The etching depths (in micrometres) after 6 min were: TiF sub(4) 0.8 (SD 0.8), SnF sub(2) 3.5 (SD 0.7), NaF 5.3 (SD 0.4), and 7.0 (SD 0.3) for the control specimens. Compared to the control, TiF sub(4) protected the enamel surface from acid attack almost completely (88%), while SnF sub(2) reduced the etch depth after 6 min by 50% and NaF by 25%.