Remineralization Effect of Eggshell versus Nano-hydroxyapatite on Caries-like Lesions in Permanent Teeth (In Vitro)

Background: Eggshell (ES) is a rich source of minerals since it contains calcium, phosphorous, magnesium, strontium, and fluoride. This study sought to compare the efficacy of nano-hydroxyapatite (NHA) and ES for remineralization of enamel caries-like lesions by pH cycling. Materials and Methods: In this in vitro experimental study, artificial enamel carious lesions were induced in 47 human teeth using an acidic buffer solution. Deionized water was used as the control group, and 10% NHA and 3% and 10% ES powders in deionized water were tested as therapeutic agents. The surface microhardness of the samples was measured by a Vickers hardness tester before and after demineralization and after the application of therapeutic agents in a 7-day pH-cycling model. The data were analyzed using repeated measures analysis of variance. Results: Microhardness significantly decreased in all samples after demineralization and significantly increased after exposure to therapeutic solutions. Microhardness of the samples was not significantly different among the therapeutic groups after pH cycling. Conclusion: Based on the results of this study, ES can be used as a remineralization agent in enamel caries-like lesions.