Effect of application sequence of fluoride and CPP-ACP on remineralization of white spot lesions in primary teeth: An in-vitro study.

OBJECTIVE: To explore how application sequence of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and fluoride influences remineralization of enamel white spot lesions (WSL) in primary teeth. DESIGN: In this in-vitro study, artificial WSLs were created in 130 primary teeth. Teeth were divided into 4 groups (n=27) and a control group (n=22) and exposed to one of the following remineralization regimens for 10 weeks: Group-1; 500ppm fluoride dentifrice; Group-2; 10% w/v CPP-ACP; Group-3; fluoride applied first, then CPP-ACP; Group-4; CPP-ACP applied first, then fluoride, and Group-5 was control. All groups were kept in a remineralizing solution. Mineral changes (DeltaF) were quantified weekly using quantitative light-induced fluorescence. Statistical analysis was done using Statistical Package for the Social Sciences (SPSS version 20.0). RESULTS: Remineralization occurred in all groups to different degrees; changes from baseline were significant in groups 1-4 (P</=0.05). Group-4 showed the earliest significant remineralization (after 2 weeks) among groups, (P<0.001). Group-4 showed maximum changes in DeltaF among groups; however, only differences with Groups 1 and 5 were significant (P<0.05 and P<0.01, respectively). Group-3 showed better remineralization than Groups 1, 2 and 5; however, the difference was only significant with Group-5 (P<0.001). There were no significant differences between Group 1and 2, however, only Group 2 showed better remineralization than Group 5, (P<0.01). CONCLUSION: Combined treatment with CPP-ACP followed by fluoride exhibited the best remineralization of white spot lesions in primary teeth in this study. Combined treatment with fluoride followed by CPP-ACP showed a tendency towards better remineralization than fluoride or CPP-ACP alone.