Purpose: To evaluate the efficacy of 10% casein phosphopeptide amorphous calcium phosphate complex (CPP-AC P) used alone or with fluoride as compared to fluoride mouthrinse for the remineralisation of occlusal white spot lesions in an in vivo pilot study. Materials and Methods: Forty-five subjects with occlusal white spot lesions (WSL) determined by visual examination and confirmed with Diagnodent were randomly divided into 3 groups: group 1: 10% CPP-AC P + 0.2% NaF; group 2: 10% CPPAC P; group 3: 0.5% NaF mouthrinse for 30 days. The pre-treatment and post-intervention Diagnodent values were tabulated and subjected to statistical analysis. Results: Among the groups, the remineralising potential of 10% CPP-AC P + 0.2% NaF (group 1) and 10% CPP-AC P (group 2) were similar, however, both groups were superior to 0.5% NaF mouthrinse (group 3). Conclusions: The CCP-AC P technique is highly beneficial for the remineralisation of non-cavitated occlusal white spot lesions when compared to 0.5% NaF mouthrinse. Schlagwörter: casein phosphopeptide amorphous calcium phosphate complex (CPP-AC P), diagnodent, fluoride, remineralisation, white spot lesion