Comparison of the newer preventive therapies on remineralisation of enamel in vitro.

OBJECTIVES: To investigate in vitro the effect of MI Paste, MI Paste Plus and 2800ppm fluoride (F) toothpaste (TP) on the remineralisation of enamel subsurface lesions and to compare these to the effect of 1450ppm and 0ppm F toothpastes. METHODS: Enamel subsurface lesions were created in bovine enamel slabs (n=120) which were assigned randomly to five groups; (1) 0ppm F TP, (2) 1450ppm F TP, (3) 2800ppm F TP, (4) 1450ppm F TP+MI Paste (Tooth Mousse-TM,10% w/v CPP-ACP) and (5) 1450ppm F TP+MI Paste Plus (Tooth Mousse Plus,10% w/v CPP-ACP, 900ppm F as 0.2% w/w sodium fluoride). The enamel slabs were subjected to a pH cycling regimen for 21days. Quantitative Light-induced Fluorescence (QLF) images were taken and analysed. Data analysis was carried out using one way ANOVA. RESULTS: In all groups, both DeltaF (percentage fluorescence loss) and DeltaQ (DeltaF times the area) values improved significantly within the same group after the treatment. In addition, the mean difference in DeltaF of the non-fluoride control group was significantly lower than all other groups but not for the 2800ppm F(-) group. Whereas the mean difference in DeltaQ of the non-fluoride control of group was significantly lower when compared with all other groups (p<0.05). CONCLUSIONS: Both MI Paste and MI Paste Plus when used in conjunction with 1450ppm F did not show a significant increase in efficacy for the remineralisation of bovine enamel subsurface lesions in the model used in this study. CLINICAL SIGNIFICANCE: Newer preventive agents such as MI paste and MI paste plus are advocated as promoting remineralisation when used in addition to routine oral care. This in vitro study shows that they may have a limited value in promoting remineralisation over and above that of 1450ppm F toothpaste used twice a day.