Objective:
The purpose of this study was to measure the initial effectiveness and the shade rebound of two home bleaching agents after 6 months.Methods: A total of sixty six patients ranging in age from 18 to 65 years were selected and were randomly assigned to one of two experimental groups. Group 1 was treated with 10% carbamide peroxide (Opalescence ®) and Group 2 was treated with a 7.5% hydrogen peroxide (Day White 2 ®). Visual shade was determined by comparing a maxillary central incisor to a value oriented Vita shade guide. Color change was determined in D E values by using a small-area colorimeter (Minolta Chroma Meter II ®). Initial measurements were recorded at baseline and 3 weeks; rebound effect at 7 weeks and 6 months. Means and standard deviations were calculated for visual shade changes and for D E measurements. A Students t-test was used to evaluate significance in color difference measurements between the two treatments at each time interval.
Results:
| D E
Group 1 | D E
Group 2 | Shade Change Group 1 | Shade Change Group 2 | |
| Initial Change Bs – 3w | 8.02 (5.52) | 11.61 (11.65) | 7.67 (2.63) | 7.42 (2.02) |
| Rebound 3w – 7w | 11.22 (8.51) | 10.53 (8.41) | - 0.34 (1.29) | - 0.72 (1.91) |
| Rebound 7w – 6m | 7.56 (3.39) | 11.33 (10.96) | - 1.17 (2.01) | - 0.59 (1.62) |
Conclusions: