Effects of 10% carbamide peroxide on the enamel surface morphology: a scanning electron microscopy study

Several studies have been published about the effect of carbamide peroxide on enamel surface morphology. However, only a few studies have been carried out under intraoral conditions. The purpose of this study was to investigate the effect of two commercially available 10% carbamide peroxide bleaching products (Colgate Platinum and Starbrite) on the enamel surface morphology under intraoral conditions.

Twenty-four subjects were divided into two groups and assigned a product to use for 2 weeks. Epoxy resin replicas obtained from the maxillary right central incisors of the subjects before, immediately after, and 3 months after the bleaching procedure were examined under a scanning electron microscope.

Immediately after the bleaching procedure, the surface porosity of enamel had increased in the Colgate Platinum group, whereas erosive surface alterations were observed in the Starbrite group. At 3 months, the surface morphology of enamel in the Colgate Platinum group was similar to the untreated enamel surface. In the Starbrite group, erosive defects on the enamel surface had decreased within 3 months, and the appearance of the enamel surface was almost the same as the untreated enamel.

Even though both bleaching agents caused alterations in the surface morphology of enamel, these alterations were reversed within 3 months following treatment.

The results of this study suggest that 10% carbamide peroxide bleaching products cause alterations in enamel surface morphology immediately after bleaching, and the degree of these alterations depends on the brand of bleaching agent and duration of application time. However, these alterations revert to almost normal within 3 months.