Nightguard vital bleaching: Effects of various solutions on enamel surface texture and color

The purpose of this in vitro study was to determine the effects of three commercially available 10% carbamide peroxide solutions and a 1.5% hydrogen peroxide solution on enamel surfaces and color. The crowns of forty freshly extracted human teeth were sectioned in half incisogingivally. One half was bleached for 250 hours total treatment time. The other half of each tooth was subjected to the same protocol in distilled water solutions. The color of both the treated and control halves was determined using a colorimeter. There was no significant difference between any of the control groups, and each treated group was significantly lighter than its corresponding control group. The control and treated halves of samples of each group were then sputter coated and examined for differences in surface morphology and were compared to enamel etched with 37% phosphoric acid. No significant differeces in enamel surface texture were detected between the treated and control enamel surfaces of the teeth in any of the groups. However, the enamel surfaces in all groups differed significantly from conventionally etched enamel.