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

Abstract

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.

Assessment of the Additive Effect of Remineralizing Agents in Combination With Fluoride Releasing Adhesives in the Prevention of Enamel Decalcification in Orthodontic Patients: An In Vitro Study

“…The initial stage is characterized by subsurface lesions that demonstrate dissolution of the subsurface lesion of the enamel with an intact outer surface layer of the enamel. The fluorides are effective at this stage [ 5 , 6 , 11 ]. The next stage is surface relaxation, which is characterized by the loss of minerals from the outermost layer.…”

“…During this stage, if the proper concentration of calcium and phosphate ions is maintained in the immediate environment of the enamel surface, remineralization ensues with the passage of these ions back to the enamel surface. This is where the remineralization agents play an important role [ 5 , 6 , 11 ]. The WSL is formed at the outer edge of the bracket, and these brackets are connected using orthodontic adhesives.…”

“…Remineralizing compounds control the demineralization/remineralization cycle in favor of enamel. These compounds work by influencing the microenvironment surrounding the tooth [ 5 ]. Remineralizing agents, such as fluoride varnish, self-assembling peptide, sodium phosphosilicate, sugar substitutes, calcium phosphate systems, ozone, hydroxyapatite, and resin infiltrates, are available on the market to aid in the process of remineralizing the tooth structure [ 6 ].…”