Effect of Bioactive Glass Versus Resin Infiltration (ICON) on the Depth of White Spot Lesions: An in Vitro Study

White spot lesions are an adverse result of orthodontic treatment caused by poor oral hygiene. It is difficult to maintain oral hygiene during fixed orthodontic treatment.White spot lesions are subsurface enamel porosities due to demineralization of enamel. They are basically the early stages of caries and has milky white appearance. WSLs are usually formed four weeks after bracket placement.There are various methods for the treatment of white spot lesions. The invasive methods include crowns or veneers and microabrasion. The non-invasive methods are remineralizing agents like topical fluoride, bioactive glass, GC Tooth Mousse and resin infiltration material (ICON). Fluoride compounds are one of the first therapies for WSL. Fluoride varnishes inhibit the demineralization process and promotes the remineralization of enamel. The fluoride varnish forms the calcium fluoride on enamel surface and prolong the contact between fluoride and enamel.Previous studies have shown promising results achieved by bioactive glass as compared to other remineralizing agents. Resin infiltration has been introduced recently and there are few studies on the treatment of WSLs. The rationale of the study is to compare the effects of bioactive glass and resin infiltration through scanning electron microscopy and microhardness, as there is limited research on this topic. The purpose of this study is to compare and evaluate the lesion depth of artificial white spot lesions before and after the treatment with sodium fluoride varnish, bioactive glass and resin infiltration (ICON). The null hypothesis is that there are no significant differences among the three groups for the treatment of white spot lesions.