Evaluation of the efficacy of fluoridated and non-fluoridated remineralization agents applied by different methods on remineralization of early enamel lesions

This study evaluated the effect of pastes containing amorphous calcium phosphate (ACP) and hydroxyapatite (HA) with and without fluoride applied by finger and toothbrush on enamel demineralization. Human teeth were used. After artificial caries lesions were formed, they were addressed to 9 groups each group contained 13 specimens, 10 for microhardness test and 3 for SEM analysis. The specimens were demineralized by the pH cycling model for 8-hour intervals, after demineralization the remineralization agents were applied to all groups for 3 minutes and then cleaned with artificial saliva. Specimens were stored in artificial saliva for 16 hours for 28 days. Specimens were analyzed at baseline, after demineralization, and after 28 days of remineralization. Specimens were analyzed by surface microhardness (SMH) and SEM. T-test and the Mann-Whitney U test, One-way ANOVA, Tukey HSD and Tamhane's T2 and Bonferroni test (p<0.050). After remineralization, there is no significant difference between finger and toothbrush application methods. The HA-based has a higher microhardness mean value than ACP-based materials. The fluoridated has higher efficacy than the non-fluoridated groups. There is a significant difference between non-fluoridated ACP-based groups and the other fluoridated (HA and ACP) and non-fluoridated HA-based groups. There is no significant difference between the control group and non-fluoridated ACP-based groups. After remineralization of the SEM analysis, the control group has multi porosity with irregular rough surface same as non-fluoridated ACP-based groups, fluoridated ACP-based groups have complete coverage with irregular rough surface, while HA-based groups have complete coverage with smooth regular surface. Keywords: Early enamel lesions, Fluoridated, Non-fluoridated, Remineralization, Scanning Electron Microscopy, Hydroxyapatite.