Combined effect of casein phosphopeptide-amorphous calcium phosphate and sodium trimetaphosphate on the prevention of enamel demineralization and dental caries: an in vitro study

Objective: To evaluate the effect of treatment with fluoridated toothpaste supplemented with a combination of sodium trimetaphosphate (TMP) and casein phosphopeptide-amorphous calcium phosphate (MI Paste Plus^®) on the demineralization of dental enamel.

Methods: Bovine enamel blocks selected by initial surface hardness (SHi) were randomly allocated into six groups (n = 12), according to the test toothpastes: (1) without F-TMP-MI Paste Plus^® (Placebo); (2) 1100 ppm F (1100F); (3) MI Paste Plus^®; (4) 1100F + MI Paste Plus^® (1100F-MI Paste Plus), (5) 1100F + 3 % TMP (1100F-TMP); and (6) 1100F-TMP + MI Paste Plus^® (1100F-TMP-MI Paste Plus). Blocks were treated two times per day with slurries of toothpaste (1 min), and groups 4 and 6 received an application of MI Paste Plus (3 min). Next, the samples were subjected to five pH cycles (demineralizing/remineralizing solutions) at 37 °C, to produce subsurface enamel lesions.Thereafter, the blocks were maintained for 2 days in fresh remineralizing solution. After pH cycling, the following were obtained: percentage of surface hardness loss (%SH); integrated loss of subsurface hardness (ΔKHN); profile analysis and lesion depth subsurface through polarized light microscopy (PLM); scanning electron microscopy (SEM); and fluoride (F), calcium (Ca), and phosphorus (P) in the enamel. The data were subjected to ANOVA (1-criterion), followed by the Student-Newman-Keuls test (p < 0.001).

Results: The 1100F-TMP-MI Paste Plus group showed better results for SHR, ΔKHN, and PLM (p < 0.001). The F concentration was similar among all groups (p > 0.001). The 1100F-TMP-MI Paste Plus group showed the highest concentration of Ca and P in the enamel (p < 0.001).

Conclusion: The application of 1100F-TMP-MI Paste Plus promoted a higher inhibitory effect against enamel demineralization.

Clinical significance: The combination of treatments with F, TMP, and MI Paste Plus^® can be an effective alternative to improve the oral health of individuals, especially those with high activity of dental caries and at high risk for its development.

Keywords: CPP-ACPF; Demineralization; Dental enamel; Fluoride; Phosphate.