Effect of mouthguard bleaching on enamel surface.

PURPOSE

To evaluate in vitro the effect of 10% carbamide peroxide in a mouthguard on the shear bond strength of resin composite to bleached enamel surfaces and morphological changes in these surfaces.

MATERIALS AND METHODS

Thirty anterior extracted were divided into a control and a test group. Plastic trays were made for each tooth and the test group treated with Opalescence bleaching gel and incubated at 37 degrees C humid environment for 8 hours. The bleaching agent was washed and the trays replaced with water-soaked cotton wool for another 16 hours in the incubator. This procedure was repeated every day for 21 days. The control group was just treated with the water-soaked cotton wool. Selected teeth from both groups were evaluated with the SEM and 72 hours after the bleaching treatment, Scotchbond 2/Silux Plus rings were bonded to the enamel surfaces in both groups and sher bond strength testing performed.

RESULTS

Bleaching created some enamel porosity and significant reduction in the resin composite shear bond strength.