Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 21 0 2024 09 16 1 8 Alireza Haerian Department of Orthodontics, Faculty of Dentistry,Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, Canada Soghra Yasaei Department of Orthodontics, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Elaheh Rafiei Department of Orthodontics, Faculty of Dentistry,Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, Canada Seyed Vahid Malek Hosseini Private Practice, Yasouj, Iran Negin Karimi Department of Orthodontic, School of Dentistry, Kerman University of Medical Science, Kerman, Iran 2021 04 22 2022 01 25 Objective the main purpose of this study was to compare the effects of casein phosphopeptide amorphous calcium phosphate fluride (CPP-ACPF) and tricalcium phosphate on artificial early enamel carious lesions. Materials and Methods 45 sound extracted premolars were divided, and placed in the demineralization solution (pH=4.5) for 96 hours, divided randomly in 3 groups (TCP-MI paste Plus-Control) then they were exposed with the treating materials for 5 minutes once a day in 30 days. After mounting in the resin blocks and polishing, they were subjected to micro hardness test in 3 different depths from the surface of enamel. Data were analyzed using ANOVA test. The significance was set at 0.05. Results the average volume percent mineral (VPM) showed that in 30, 60 and 90 µm depths there was a significant difference (P Value<0.0001) between both TCP and CPP-ACPF and control group. In 30 µm depth, CPP-ACPF was more effective (P Value<0.0001) than TCP. In 60 and 90 µm depths there was no significant difference between the two groups. Conclusion In this study we concluded that both CPP-ACPF and TCP have a significant effect on the remineralization of white spot lesions of dental enamel.   https://fid.tums.ac.ir/index.php/fid/article/view/4036