Comparative evaluation of the effect of three remineralizing agents and resin infiltration on the surface microhardness of artificially demineralized enamel– an in vitro study

Aim: The aim of this in-vitro study was to compare the efficacy of three different remineralizing agents, namely: - casein phosphopeptide -amorphous calcium phosphate (CPP-ACP),calcium sodium phosphosilicate (CaSP), calcium silicate sodium phosphate salts (CSSP), and resin infiltrate (RI) in restoring the hardness of demineralized enamel using Vickers microhardness testing machine. Method: Ninety non-carious central incisors were decoronated, embedded in acrylic, and an enamel window (4mm × 4mm) was exposed. Specimens were divided into three groups: Group 1 (intact enamel), Group 2 (demineralized, no treatment), and Group 3 (demineralized with treatment), further split into four sub-groups treated with CPP-ACP, Novamin, Calcium Silicate + Sodium Phosphate, and resin infiltration. Treatments except resin were applied twice daily for 28 days. All samples were stored in artificial saliva and tested for surface microhardness using a Vickers machine. Data was statistically analyzed to evaluate enamel hardness changes. Results: The highest surface hardness was seen in Group 1 (intact enamel), while Group 2 (demineralized) showed the lowest. Among treated samples, Group 3D (resin infiltration) had the greatest hardness, followed by 3C (CSSP), 3B (CaSP), and 3A (CPP-ACP), showing that resin infiltration was most effective. Conclusion: The study found that resin infiltration is the most effective in restoring enamel hardness, closely matching that of healthy enamel. CPP-ACP, CaSP, and CSSP also improved hardness and helped prevent decay. Early use of these treatments can strengthen teeth and stop cavities from progressing.