Effect of fluoride gels supplemented with sodium trimetaphosphate on enamel erosion and abrasion: In vitro study

Abstract Objective This in vitro study aims to evaluate the effect of low fluoride (F) gel associate sodium trimetaphosphate (TMP) on erosion with or without abrasion. Design Enamel blocks (4 mm × 4 mm) selected through surface hardness (SH) is divided into five groups ( n = 12): gel without F and TMP (placebo), gel containing 4500 ppm F (4500), gel containing 4500 ppm F plus TMP5% (4500 TMP5%), gel containing 9000 ppm F (9000), and gel containing 12,300 ppm F (acid gel). Those groups were additionally subdivided into conditions of erosion (Ero) and of erosion plus abrasion (Ero/Abra). The blocks have undergone a single application of gel on the first day of the study. The erosion challenge was produced by Sprite Zero® for five minutes four times a day and abrasion was carried out by machine brushing for 15 s. After the challenges, the surface hardness (%SH), wear and cross-sectional hardness (ΔKHN) were analyzed. The data were analyzed using a 2-way ANOVA test followed by a Student-Newman–Keuls ( p < 0.05). Results Lower values of %SH, wear and ΔKHN were observed for erosion challenge ( p < 0.001). The %SH was lower in groups treated with fluoride gels, differing in the placebo ( p < 0.05). With addition of TMP to the gel 4500, enamel wear was lower when compared with another groups ( p < 0.05). Conclusion In vitro conditions, the 4500 5%TMP gel showed greatest effect against erosion and erosion/abrasion.