In situ effect of the combination of fluoridated toothpaste and fluoridated gel containing sodium trimetaphosphate on enamel demineralization.

Objective: This in situ study evaluated the effect of the association of low-F (4500μg F/g) gel containing TMP and FT (1100μg F/g) on enamel demineralization.
Methods: This crossover and double-blind study consisted of five phases of seven days each. Volunteers (n=12) wore palatal appliances containing four enamel blocks. The cariogenic challenge was performed with 30% sucrose solution (six times/day). Treatments were: placebo toothpaste (PT, no fluoride/TMP); 1100μg F/g toothpaste (FT); FT+4500μg F/g+5%TMP gel (FT+TMP gel); FT+9000μg F/g gel (FT+9000 gel) and FT+12,300μg F/g (FT+Acid gel). After topical application of treatments for one min, two blocks were removed for analysis of loosely bound fluoride (CaF ₂ ), calcium (Ca), phosphorus (P) and firmly bound fluoride (FA) formed in enamel. After the seven-day experimental periods, the percentage of surface hardness loss (%SH), integrated subsurface hardness loss (ΔKHN), CaF ₂ , Ca, P and FA retained were determined. Moreover, the biofilms formed on the blocks were analyzed for F, Ca, P and insoluble extracellular polysaccharide (EPS) concentrations.
Results: FT+TMP gel promoted the lowest%SH and ΔKHN (p<0.001). The highest concentration of CaF ₂ formed was observed for the FT+Acid gel (p<0.001), followed by FT+9000 gel > FT+TMP gel > FT > PT. CaF ₂ retained on the blocks was reduced across all groups (p<0.001). Similar values were observed for the Ca/P/F and EPS in enamel and biofilm for all fluoride groups.
Conclusion: The association of FT+TMP gel significantly reduced enamel demineralization in situ.
Clinical Significance: The association of treatments may be an alternative for patients with high caries risk.
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