In vitro evaluation of professional fluoride therapies for improving softening resistance against dental erosion

Abstract

Objective: This in vitro study evaluated the effect of professional fluoride therapies against enamel erosion. Methods: Ninety bovine enamel blocks were randomly allocated to each group: GI-Duraphat® (NaF, 2.26%F), GII-Duofluorid® (NaF, 2.71% F), GIII-TiF4 varnish (2.45% F), GIV- TiF4 solution (2.45% F), GV-no fluoride varnish and GVI-water (control). The varnishes, the solution and water were applied onto the enamel. The blocks were subjected to 6 sequential erosive cycles (cola drink for 10 min and artificial saliva for 50 min, each) per day, during 4 days. After the erosive cycles, the blocks were maintained in artificial saliva for 18 h. Enamel alterations were determined in the 2nd and 4th days, by microhardness test (%SMHC). Data were tested using ANOVA and Tukey`s tests (p<0.05). Results: The mean %SMHC (SD) in the 2nd and 4th days was, respectively: GI (-78.13±4.08a and -90.01±2.83A), GII (-77.70±5.26a and -89.63±6.08A), GIII (-88.93±2.65b and -91.90±2.4A,B), GIV (-92.23±2.21b and -97.16±1.43C), GV (-87.72±2.04b and -94.16±1.14B,C) and GVI (-88.10±1.51b and -93.12±1.93 B). Conclusion: The data from this in vitro study show that NaF varnishes were able to partially prevent softening from dental erosion until the 4th day of erosive cycle.