Effect of intracoronal bleaching agents on ultrastructure and mineral content of dentin

AIM: The purpose of this in vitro study was to evaluate the ultrastructural changes of dentin induced after exposure to different intracoronal tooth bleaching agents. MATERIALS AND METHODS: Dental discs of 1 mm thickness were prepared from coronal dentin of sixty-four human maxillary premolars. Experimental specimens were divided into four subgroups: 45% carbamide peroxide, 35% hydrogen peroxide, sodium perborate + 30% hydrogen peroxide, sodium perborate + water. The specimens were then evaluated under scanning electron microscope to determine diameter of dentinal tubules and chemical analysis. RESULTS: There was significant difference between dentinal tubule diameter of all test and control groups with the exception of sodium perborate + water. Chemical analysis revealed that there was no significant difference between experimental subgroups regarding calcium and sulfur wt%. CONCLUSIONS: All bleaching agents increased dentinal tubule diameter and promote alterations in mineral content of dentin with the exception of Sodium perborate mixed with water.