Comparison of CPP-ACP, Fluoride Varnish and Gel effects on enamel microhardness of permanent teeth: In-Vitro

Background Dental caries occurs due to the imbalance in the course of demineralization-remineralization in favor of demineralization. With remineralization, some signs of halted progression could be observed in the primary stages. The aim of this study is to in-vitro investigation of the effect of Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP), fluoride varnish, and fluoride gel on the microhardness of the enamel of permanent teeth. Materials and Methods: In this in vitro study, 344 specimens prepared from human premolars were randomly divided into four groups (n=86 specimens in each group). After preparing the specimens, the initial enamel value was first evaluated by Vickers microhardness technique. The specimens were immersed in a demineralizing solution and then treated with remineralizing compounds (I. Control, II. Fluoride varnish, III. Fluoride gel and IV. CPP-ACP). Microhardness values were re-measured at the end of demineralization and remineralization stages. The data were analyzed using SPSS software (version 16.0). Results: The results of the present study indicated a statistically significant difference in all groups in terms of initial enamel microhardness (0.288 +/- 42.77), remineralization (0.213 +/- 26.89), and demineralization values (0.167 +/- 63.87) (p < 0.001). Besides, there was a statistically significant difference in different groups in terms of remineralization values (p<0.001). In other words, the mean microhardness was 241.21 +/- 15.60 in Group III, 221.12 +/- 75.69 in Group II, 211.16 +/- 43.04 in Group IV, and 178.21 +/- 63.9 in group-I. Conclusion All remineralizing compounds resulted in enhanced microhardness of the enamel. Nevertheless, the fluoride-containing products showed greater potential in improving the level of microhardness and strength of the teeth compared to the compounds containing CPP-ACP.