Evaluation of Remineralization Potential of Two Agents and pH Cycling on Early Enamel Lesions

Purpose: The purpose of this study was to evaluate & compare the remineralization potential of two remineralizing agents on artificially induced enamel carious lesions via pH cycling. This assessment has been conducted via Surface microhardness analysis and energy dispersive X-ray(EDX) analysis. Materials and Methods: In this in vitro study, 20 human teeth were sectioned mesio-distally to obtain 40 enamel samples where artificial carious lesions were induced using an acidic buffer solution. Then samples were randomly divided into two groups (n=20) according to the material used. The first group was for Casein phosphopeptide–amorphous calcium phosphate(CPP-ACP) &the second was for Nano-hydroxyapatite paste(nHAP). Each group was further subdivided into two subgroups(n=10) according to whether subjected to pH cycling or not. The surface microhardness was measured for enamel by Vickers hardness tester at baseline, demineralization and after the application of remineralizing agents in a 15days pH-cycling model and without it. Similarly, the mineral content of the samples was estimated by EDX analysis. The data were analyzed using independent t-test, ANOVA test and Tukey’s post-hoc test. Results: Results of the microhardness showed that without pH cycling; CPP-ACP recorded a higher statistically significant difference than nHAP. Additionally, after pH cycling, CPP-ACP recorded a non-significant difference than nHAP. Moreover, EDX results revealed that the Ca/P ratio for the nHAP group recorded the highest statistically significant difference than all tested groups followed by CPP-ACP without pH cycling, baseline and CPP-ACP after pH cycling, respectively. Conclusion: CPP-ACP and nHAP both had a positive effect on causing remineralization of enamel. Nano-hydroxyapatite was more effective as compared to CPP-ACP, in increasing the calcium and phosphorus content of enamel in both presence and absence of pH cycling. Codex : 01/22.01 azhardentj@azhar.edu.eg http://adjg.journals.ekb.eg DOI: 10.21608/adjg.2021.39074.1287 Restorative Dentistry (Removable Prosthodontics, Fixed Prosthodontics, Endodontics, Dental Biomaterials, Operative Dentistry)