Beyond The White Smile: In Vitro Insights into Carbamide Peroxide Bleaching by Confocal Microscopy

Abstract

1.Background/Objectives: Tooth bleaching with carbamide peroxide (CP) is one of the most common aesthetic procedures in modern dentistry, yet its effects on enamel ultrastructure remain a matter of concern. This in vitro study aimed to qualitatively assess microstructural changes in human enamel following in-office bleaching with two professional CP formulations—Opalescence Quick 45% and Pola Office+ 37.5%—in accordance with ISO 28399:2021 guidelines. 2.Methods: Forty extracted human molars and premolars were sectioned to obtain paired specimens, with one half treated and the other serving as control. Bleaching protocols were performed under standardized conditions, and samples were analyzed using laser scanning confocal microscopy (CLSM) with three-dimensional reconstruction to evaluate enamel prism organization, porosity, and dentinal tubule exposure. 3.Results: Both agents induced morphological alterations, including partial prism disorganization, increased porosity, and widening of interprismatic spaces. Opalescence Quick, with its higher CP concentration, produced more pronounced structural effects compared with Pola Office+, which exhibited a more moderate impact. Despite these changes, enamel integrity was not severely compromised. 4.Conclusion: These findings suggest that carbamide peroxide bleaching can be considered safe when performed under professional supervision, particularly when complemented with remineralizing strategies. Future studies should investigate long-term effects and interactions with restorative materials under clinical conditions.