Biomineralization and remineralizing potential of toothpastes containing nanosized β-calcium glycerophosphate: an in vitro study

To evaluate the effect of 1100 ppm F toothpastes supplemented with micrometric or nanosized beta-CaGP (beta-CaGPm/beta-CaGPn) on artificial enamel remineralization, using a pH cycling model. Enamel blocks with artificial caries were randomly allocated into ten groups (n = 10), according to the toothpastes: without fluoride/beta-CaGPm/beta-CaGPn (negative control); 1100 ppm F (1100F); 1100F plus 0.125%, 0.25%, 0.5%, and 1.0% of beta-CaGPm or beta-CaGPn. The blocks were treated 2x/day with slurries of toothpastes. After pH cycling, the percentage of surface hardness recovery (%SHR); integrated loss of subsurface hardness (Delta KHN); integrated mineral loss (Delta IMR); fluoride (F), calcium (Ca), and phosphorus (P) concentrations in the enamel; polydispersity index (PdI); and zeta potential (Zp) were determined. The data were analyzed by ANOVA (p < 0.001). For Zp/PdI, no significance was observed when comparing the means (p > 0.001). The treatment with 1100F-0.25%beta-CaGPn led to %SHR similar to 57 higher when compared to the 1100F group (p < 0.001). The lowest Delta KHN was observed for the 1100F-0.25%beta-CaGPn group (p < 0.001). The Delta IMR was lower (similar to 201%) for the 1100F-0.25%beta-CaGPn when compared to 1100F (p < 0.001). The association of beta-CaGPm and beta-CaGPn to 1100F did not influence its F concentration (p > 0.001). The highest increase in Ca and P was observed for 1100F-0.25%beta-CaGPn (p < 0.001). The addition of 0.25%beta-CaGPn to 1100F toothpaste was able to promote an additional remineralizing effect of artificial caries lesions.