Date of Award
Master of Science (MS)
Objective:A popular product to facilitate removal of excess adhesive during bonding of orthodontic appliances is a color changing adhesive. Before polymerization, these materials are a bright color but upon curing, manufacturers claim they become translucent. After debonding, there is often resin embedded within the enamel, so the appearance of these materials after polymerization can affect the esthetics of a patient’s dentition. The purpose of this study was to analyze the color characteristics of various orthodontic color changing adhesives and determine if there is a significant difference in color changing capabilities and in translucency after polymerization between products. Methods:Grengloo and Blugloo by Ormco, BracePaste Color Change by American Orthodontics and Transbond PLUS by 3M Unitek were evaluated. As a non-color changing control, Transbond XT by 3M Unitek was analyzed. A teflonTeflon mold was used to fabricate uniform discs of adhesives (n=10/adhesive). A spectrophotometer was used to analyze the color (L*a*b* values), color change (∆E_ab^*) and translucency at various polymerization stages. The samples were analyzed at 20.6℃ and at 37.0℃. Specimens were stored in Fusayama Meyer artificial saliva. Statistical analysis was completed with ANOVA, pairwise comparison analysis, t-test and response profile analysis. P values less than 0.05 were considered significantly different. Results: All materials demonstrated an increase in L* upon polymerization, but there was no trend in the changes noted with a* and b* values. There was a significant (p < 0.05) difference in the color change between the materials during all stages of polymerization. Transbond Plus showed the largest color change during initial polymerization, and Grengloo had the smallest change. Upon a decrease in temperature, Transbond XT and BracePaste had minimal color change, and Blugloo and Grengloo had the largest change. Each color changing composite had significantly (p < 0.05) lessdifferent translucency when compared to Transbond XT. Conclusion: All of the color changing composites that were evaluated have significantly different color changing capabilities. Temperature plays a significant role in the appearance of Blugloo and Grengloo. The translucency after polymerization of all the color changing composites is significantly different less thanfrom Transbond XT, with Blugloo and Grengloo having the largest difference.