Effect of light-cured adhesives on color relapse after cold light tooth whitening / 中国组织工程研究

ABSTRACT

BACKGROUND: Most studies suggest tooth whitening can create a coarse enamel surface which is likely to attract exogenous dyeing material and form the phenomenon of color relapse. After dental bleaching procedure, the use of resin surface treatment agent is expected to make the enamel surface smooth and alleviate tooth color relapse. OBJECTIVE: To unravel the efficacy of Adper Single Bond 2 Adhesive on color relapse phenomenon after dental bleaching treatment by cold light (xenon laser) whitening.METHODS: Twenty-four extracted teeth were collected and coated with 35% hydrogen peroxide followed by xenon laser whitening. The test group was made up of 12 samples coated with light-cured resin surface treatment agent and the left samples as control group were treated with no-coating agent after tooth whitening. Then the two groups were divided into two subgroups which were soaked in distilled water and tea for aging test respectively. The color differences (ΔE) which provided comparative values for statistical analysis was recorded at 1, 3, 5, 7, 14, 21, 28, 35 and 42 days after the aging test. The enamel surface microstructure of the samples was observed before and after bleaching, after resin agent coating, and 28 days after the aging test.RESULTS AND CONCLUSION: (1) Results from color differences observation: there was no significant difference between samples soaked in distilled water before and after whitening treatment (P > 0.05). Similarly, there was no statistical difference between test group and control group soaked in distilled water (P > 0.05). However, after soaking in tea, the color differences in the test group at 1-42 days showed statistically significant differences from those in the control group (P < 0.05). (2) Results from scanning electron microscope observation: after the tooth whitening producers, the enamel surface was damaged in the presence of cavities. After coated with resin surface treatment agent, the enamel surface became smooth and had few cavities. After soaking in tea, gradient smooth surface, some crack, inconspicuous flake dyeing color layer decomposition could be seen in the test group while rough surface with big holes and mottled dyeing layer were clearly visible in the control group. All samples soaked in distilled water had only a small amount of block dyeing layer, holes, weaker roughness than those soaked in tea. To conclude, Adper Single Bond 2 Adhesive light-cured resin surface treatment agent could weaken color relapse phenomenon after tooth whitening, achieving a smooth enamel surface and reducing dyeing material adhesion.