In vitro enamel erosion and abrasion-inhibiting effect of different fluoride varnishes

- The authors investigated the erosive and abrasive inhibiting effect of CPP-ACP/NaF and xylitol/NaF varnishes on dental enamel.
- A single-application of fluoride topical varnishes was effective in reducing enamel wear.
- CPP-ACP/NaF varnish had the best effect against enamel loss from erosion-abrasion challenge.
- These findings provide a basis for future studies to determine the effect of CPP-ACP/NaF varnish in preventing clinical erosive tooth wear.

ObjectiveTo investigate the erosion and abrasion inhibiting effect of CPP-ACP/NaF and xylitol/NaF varnishes.MethodsBovine enamel samples (n = 40) were exposed to the following treatments (n = 10): NaF varnish (Duraphat®, positive control); CPP-ACP/NaF varnish (MI varnishTM); xylitol/NaF (Profluorid®) or distilled and deionized water (MilliQ®, negative control). The samples were submitted for 3 days to 4 cycles/day of erosion (5 min in Sprite Zero) and 2 cycles of abrasion/day after the first and last erosive challenge, with a toothbrush machine and slurries of a placebo toothpaste for 15 s (50 strokes/s). Among the cycles and after the last daily cycle, the specimens remained in artificial saliva. The change in the enamel surface was evaluated by using 3D non-contact optical profilometry with surface roughness (Ra and Sa values) and tooth structure loss (TSL) measurements. Scanning electron microscopy (SEM) assessed the enamel topographic characteristics. Differences in the Ra, Sa and TSL among treatments were tested using one-way ANOVA followed by the Tukey test.ResultsAll varnishes promoted better results for Ra and Sa values than the negative control (p = 0.0001), without difference among them (p > 0.05). However, CPP-ACP/NaF varnish stimulated fewer TSL (7.09 ± 0.70 μm) compared to NaF varnish (10.33 ± 1.36 μm, p = 0.002), xylitol/NaF varnish (9.96 ± 0.41 μm, p = 0.007) and the negative control (18.38 ± 3.32 μm, p = 0.0001).ConclusionA single-application of fluoride topical varnishes was effective in reducing enamel wear. The CPP-ACP/NaF varnish had the best effect against enamel loss from an erosion-abrasion challenge.