In situ remineralization of enamel caries lesions with a toothpaste supplemented with fluoride, amorphous calcium phosphate casein phosphopeptide and trimetaphosphate

Objectives: This in situ study aimed to evaluate the effect of a new toothpaste formulation containing fluoride (F), casein phosphopeptide amorphous calcium phosphate (CPP-ACP) and sodium trimetaphosphate (TMP) on the remineralization of initial caries lesions. Methods: This was a blind, crossover study, performed in 5 experimental phases with a duration of 3 days each. At first, the initial surface hardness (SH) and hardness after demineralization (SH1) were determined. Then, volunteers (n = 10) used palatal appliances containing 4 bovine enamel specimens with initial caries lesions. The treatment regimens were: 1) Placebo (No F-TMP-CPP-ACP), 2) 1100 ppm F (1100F), 3) 1100F+3 %TMP (1100F-TMP), 4) 1100F+10 %CPP-ACP (1100F-CPP-ACP) and 5) 1100F-CPP-ACP-TMP. After 3 days, the final surface hardness (post-remineralization) (SH2), percentage of surface hardness recovery (%SHR), integrated recovery of subsurface hardness (ΔIHR), fluoride- (F), calcium- (Ca) and phosphorus- (P) concentration in the enamel were determined. Data were analyzed by ANOVA (one-way, repeated measures) and Student-Newman-Keuls test (p < 0.05). Results: The enamel surface showed greater remineralization (SH2) when treated with 1100F-CPP-ACP-TMP (224.8KHN±1.6) compared to 1100F (163.9KHN±2.0) (p < 0.033). Treatment with 1100F-CPP-ACP-TMP led to remineralization of the subsurface lesion (ΔIHR) by 84 % and 91 % when compared to the 1100F and 1100F-CPP-ACP treatments (p < 0.05). For the F concentration values in the enamel, there was an increase of ⁓ 63 % compared to 1100F (p < 0.05). The Ca concentration in the enamel after 1100F-CPP-ACP-TMP treatment was significantly higher in ⁓ 65 %, ⁓ 28 % and ⁓ 15 % when compared to the 1100F, 1100F-CPP-ACP and 1100F-TMP treatments (p < 0.05). The highest concentration of P was observed for 1100F-ACP-CPP-TMP, which was ⁓ 41 % and ⁓ 17 % higher than the 1100F and 1100F-TMP treatments respectively (p < 0.05). Conclusion: The result of this study demonstrates that the combined use of remineralizing agents (F, CPP-ACP, and TMP) in a single toothpaste formulation (1100F-CPP-ACP-TMP) significantly enhances mineral gain compared to conventional toothpaste, as evidenced by a short-term in situ model. Clinical significance: The findings of our study offer essential insights for future investigations and potential clinical applications, especially for individuals with initial caries lesions.