The Erosion and Abrasion-inhibiting Effect of Fluoride Varnishes With CPP-ACP or Xylitol on Enamel In Vitro

Objectives: The aim of this study were to compare the effect of fluoride varnishes to protect against enamel erosion plus abrasion.
Methods: Forty bovine enamel samples were randomly divided into 4 groups (n=10). Enamel specimens were pre-treated with varnishes and keep on relative humidity for 12 hours. G1= CPP-ACP + NaF (2.26% F), G2= NaF + xylitol (2.26% F), G3= NaF (2.26% F) and G4= negative control (Mili-Q water). The erosive challenge was performed using a soft drink (pH 2.6, 30 mL⁄sample), 4 times/day for 5 minutes and the tooth-brushing abrasion 2 times/day for 15 second, during 3 days. Between the challenges for 2 hours and after the last daily erosive treatment, the specimens were exposed to artificial saliva (pH 7.0, 30 mL⁄sample). Enamel loss (Gap) and roughness (linear-Ra and volumetric-Sa) were measured using the 3D non-contact profilometry technique.
Results: Anova⁄Tukey tests showed that all fluoridated varnishes (G1=7.16 ± 0.95, G2=9.84 ± 0.60, G3=10.00 ± 1.87) were able to significantly reduce enamel loss when compared with control (G4= 18.38 ± 3,32)(p< 0.0001). All groups were able to significantly reduce the roughness alteration on enamel (Ra and Sa) after erosion and abrasion when compared with control (p< 0.0001). G1 was statistically different from G2 and G3 (p< 0,05).
Conclusions: Based on the results, it can be concluded that although tested varnishes significantly reduced enamel loss and roughness alterations after erosion with abrasion, the best performance was observed with CPP-ACP varnish, so it seems to be a promising treatment to protect enamel from erosion and abrasion.