Evaluation of the Anti-cavity Efficacy of Three Dentifrices Using an Intra-oral Enamel Demineralization - Remineralization In-Situ Model

This clinical study aims to evaluate the anti-cavity efficacy of dentifrices using an intra-oral enamel demineralization-remineralization in-situ model. It is a Phase III, randomized, triple-blind, crossover study involving 36 participants aged 18 to 70. Participants will use an intra-oral appliance with a steel mesh holding bovine enamel blocks, properly disinfected before using. Participants will be divided into three groups of treatment: one using a fluoride-free toothpaste with a chalk base and herbal ingredients, another using a fluoride toothpaste containing 1000 ppm MFP and 1.5% arginine in a PCC/RNCC base, and a negative control group using a fluoride-free toothpaste in a PCC/RNCC base. Each participant will receive a soft-bristle toothbrush and will be instructed to brush twice daily for 6 weeks. Additionally, between the treatment phases (5 days), 9-day washout phases will occur, during which participants will use a fluoride-free toothpaste in a PCC/RNCC base. Subjects will undergo baseline visit, visit 2 - washout I (9 days), visit 3 - treatment phase I (5 days), visit 4- washout II, visit 5- treatment phase II, visit 6 - washout III, visit 7 - treatment phase III, visit 8 - final visit. The primary outcome will be enamel microhardness, measured before and after treatment, to assess changes in microhardness. The expected outcome is the confirmation of the alternative hypothesis, which predicts a reduction in the percentage of mineral loss from the surface of bovine enamel after using dentifrices containing 1000 ppm MFP with 1.5% arginine or herbal ingredients for five days each, compared to the control group. The percentage of mineral loss on the tooth surface relative to baseline will be used to quantify the extent of reduction in enamel demineralization. A two factor ANCOVA using the baseline as the covariate will be conducted to determine if a significant treatment effect exists. Adverse events and compliance will be closely monitored, with strict confidentiality maintained for all participants.