Objective: The aim of this study was to compare the protective effect of TiF(4), SnF(2), and NaF treatment on the development of erosion-like lesions in pellicle-covered human enamel.
Material and methods: Twelve human molars were each divided into 5 specimens, 4 of which were immersed in saliva for 2 h. Three pellicle-covered specimens from each tooth were treated with a TiF(4), SnF(2), or NaF solution (all 0.5 M F) for 2 min. Control specimens, one with and one without pellicle, were included. Immersion in acid (0.01 M HCl) was carried out stepwise (2+2+2+2 min). The etching depths (in microm) were measured using white light interferometry.
Results: Compared with the control with pellicle, TiF(4) reduced enamel loss by 100% after 2 min and by 24% after 8 min of acid exposure. The corresponding values for SnF(2) were 45% and 14%. NaF provided no significant protection of the surface. The pellicle-covered specimens showed reduced lesion depths after 6 and 8 min compared to the controls without pellicle.
Conclusions: TiF(4) gave the best protection against acid attack. SnF(2) provided significant protection only after 2 min of acid exposure, while NaF had no significant protective effect.