Remineralization of initial enamel caries in young permanent teeth: an in vitro comparison of P11-4 peptide gel and therapeutic toothpastes

This study aimed to evaluate the remineralization efficacy of a self-assembling peptide P 11 -4 gel combined with a standard toothpaste, compared with various therapeutic toothpastes, on initial enamel carious lesions in young permanent teeth. A total of 66 extracted maxillary premolars were divided into six experimental groups: PC: Oral-B Kids (1100 ppm fluoride positive control); BF: BioMin F (530 ppm fluoride-containing bioactive glass); CTC: Clinpro Tooth Crème (950 ppm fluoride with functionalized tricalcium phosphate); PC + CP-2: Positive control+Curodont Protect (1100 ppm fluoride + P 11 -4 peptide, applied twice weekly); PC + CP-7: Positive control+Curodont Protect (1100 ppm fluoride + P 11 -4 peptide daily); CD: Colgate Duraphat (5000 ppm fluoride). Following a 96-hour demineralization period, the specimens were subjected to a 14-day pH-cycling regimen. During this cycle, the specimens were brushed for two minutes twice daily in a brushing simulator using the assigned toothpaste. In addition to the PC regimen, Curodont Protect gel was applied twice weekly to the PC + CP-2 group and daily to the PC + CP-7 group. Enamel changes were assessed using microhardness, quantitative light-induced fluorescence (QLF), and confocal laser scanning microscopy (CLSM). The data were analyzed using paired t-tests, one-way ANOVA (Bonferroni/Tamhane’s T2), repeated measures ANOVA, Kruskal-Wallis, Friedman tests, effect size analyses, and Pearson/Spearman correlation analyses. All analytical methods demonstrated that CD exhibited significantly higher remineralization efficacy than the other groups ( p < 0.05). PC + CP-7 also showed markedly greater remineralization than all other groups except for the CD group ( p < 0.05). In conclusion, within the limitations of this in vitro study, both high-concentration fluoride toothpaste and daily P 11 -4 gel demonstrated substantial remineralization capacity, supporting targeted, risk-based noninvasive management of early enamel lesions.