S.Swathi Priyadharshini
* 
, ashiyana syed, ragavendran chinnasamy, anand sherwood
Abstract
Background: This study aimed to investigate the effects of at-home bleaching on enamel surface morphology and assess the potential of carbonated hydroxyapatite (CHA) as a remineralizing agent compared to casein-phosphopeptide-amorphous calcium phosphate nanocomplex (CPP-ACP). Methods: Extracted premolars were divided into four groups: Group 1: no treatment; Group 2: treated with 22% carbamide peroxide; Group 3: treated with 22% carbamide peroxide followed by remineralization with CPP-ACP ; and Group 4: treated with 22% carbamide peroxide followed by remineralization with CHA. After bleaching with 22% carbamide peroxide, remineralization agents were applied for seven days. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy were used to evaluate surface morphology and elemental composition. Results: All other groups showed a statistically significant reduction in calcium and phosphorus levels and an increase in carbon content compared to Group 1 (P = .000). Group 4 (bleached and CHA-treated) had the highest carbon content (40.2 ± 0.9 mg/g). SEM analysis revealed a smooth enamel surface in Group 1, while Group 2 (bleached) displayed increased surface irregularities. Groups 3 and 4, treated with CPP-ACP and CHA, respectively, showed significant mineral deposition on the enamel surfaces. Conclusion: At-home bleaching with 22% carbamide peroxide caused enamel damage and mineral loss.Both CPP-ACP and CHA demonstrated potential for remineralization following bleaching.