Synergistic effect of fluoride and sodium hexametaphosphate in toothpaste on enamel demineralization in situ

5 years ago

Synergistic effect of fluoride and sodium hexametaphosphate in toothpaste on enamel demineralization in situ

To evaluate the effect of a fluoride dentifrice containing sodium hexametaphosphate (HMP) on enamel demineralization in situ.

Methods

This double-blind and cross-over study consisted of 3 phases (7 days each) in which 12 volunteers wore intraoral appliances containing four enamel bovine blocks. Specimens were treated (3×/day) with placebo (no F or HMP), 1100ppm F (1100F) and 1100F plus HMP1% (1100F-HMP1%) toothpastes, and the cariogenic challenge was performed using a 30% sucrose solution (6×/day). Final surface hardness, the percentage of surface hardness loss (%SH), the integrated loss of subsurface hardness (ΔKHN), as well as enamel calcium (Ca), phosphorus (P) and firmly-bound fluoride (F) were determined. Also, biofilm formed on the blocks were analyzed for F, Ca, P and insoluble extracellular polysaccharide (EPS) concentrations. Data were submitted 1-way ANOVA, followed by Student–Newman–Keuls’ test (p <0.05).

Results

1100F-HMP1% promoted the lowest %SH and ΔKHN among all groups (p <0.001). The addition of HMP1% to 1100F did not enhance enamel F uptake, but significantly increased enamel Ca concentrations (p <0.001). Similar EPS concentrations were seen for 1100F-HMP1% and 1100F groups (p >0.05). All the groups were supersaturated with respect to HA. However, only 1100F-HMP1% group was supersaturated with respect to CaF2 (p <0.05). The ionic activities of F⁻, CaF⁺ and HF⁰ for the 1100F-HMP1% group were the highest among all groups (p <0.001).

Conclusion

The addition of HMP1% to a conventional toothpaste significantly reduces enamel demineralization in situ when compared to 1100F.

Clinical relevance

This dentifrice could be a viable alternative to patients at high risk of caries.

Publisher URL: www.sciencedirect.com/science

DOI: S0300571215300324