Six-month Rebound Evaluation of Subjects Treated with a 15% Carbamide Peroxide Gel; Quantitative Assessment by Standard Digital Photography

Objective: To evaluate the color stability of tooth bleaching over a period of 6 months. Methods: The rebound of 23 patients (138 measurements) who had undergone a 2-week treatment with a 15 % carbamide peroxide whitening system on the maxillary anterior teeth were digitally photographed. The subjects were recalled 6 months post bleaching and digital photos were taken utilizing an Olympus 2500L standard digital camera. Color corrected 5,500K fluorescent bulbs and camera settings were documented and maintained for both visits. Vitapan Classic and 3D Master shade guides were used as controls to insure maintenance of camera and photographic settings. Photographic analysis software (Adobe) was used to generate the CIE color L*a*b* scores. The left central, lateral and canine were sampled in the middle-incisal third and the middle-middle third. The average of the anterior dentitions scores were taken to represent the mean rebound. The difference between the L*a*b* score at the end of bleaching and 6 months later define the mean change in color or rebound. A t-test was used to compare the mean color change. The mean difference between individual Vitapan Classic shades was used as a reference to compare L*a*b* scores. Results:

Conclusion: The mean shade change post bleaching at 6 months significantly (P<0.05) darkened than baseline bleaching. The difference in color change (ie. A1 to B2) was at least one Vitapan classic shade. Supported in part by Philips Oral Healthcare, Inc.