The Performance of Silicate-Based Fluoride Toothpaste on Initial Enamel Caries

Objectives: To evaluate in vitro the impact of the Silicate-based fluoride toothpaste (Refix Technology) on the protection and remineralization of initial carious lesions.
Methods: Bovine enamel blocks (n=64) were submitted to a 7 days pH cycling. Specimens were randomly distributed into eight groups (n=8), four with sound enamel (protection analysis) and four with previous initial carious lesions (remineralization analysis): Silicate-based fluoride toothpaste, REFIX technology (RDC); Sensodyne Repair and Protect, NOVAMIN technology (SRP); Fluoride-free toothpaste (NC); Colgate Total Daily Repair (PC). Each day the specimens remained in a demineralizing solution for 6h and a remineralizing solution for 18h. Before and after each cariogenic challenge, specimens were treated with toothpaste slurries for 1 minute under constant agitation. The efficacy of the toothpastes was estimated by calculating the surface microhardness recovery or loss (%SMHC) and by the fluorescence recovery (ΔFRE) with quantitative light-induced fluorescence (QLF). The data were statistically analyzed (ANOVA, Tukey’s, p<0.05).
Results: All dentifrices impacted the enamel surfaces (p<0.01). Analyzing the %SMHC, the RDC and PC demonstrated a potential for both protection and remineralization (p<0.05). The SRP was similar to RDC and PC for remineralization only. The NC were different from all groups (p<0.05). The ΔFRE analysis showed that the enamel protection can be ranked as follows: RDC>PC>SRP>NC (p<0.05). No statistical difference was found between RDC and PC (p>0.05), and between SRP and NC (p>0.05). However, after treatment of the previous carious lesions, the RDC presented the highest mineral gain (p<0.05) when compared to the other groups. The NC was the only one with mineral loss after the treatment.
Conclusions: Silicate-based dentifrices with REFIX technology demonstrated greater efficacy in remineralizing and protecting enamel caries when compared to other products.