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Abstract
This study aimed to compare the effect of chemical and light activated bleaching agents on the color of conventional and bulkfill composites. A total of 90 disc shaped specimens were included in the study and divided into two main groups according to the type of composite. The groups were further subdivided into three subgroups: A control group and two groups according to the bleaching system used. The disc shaped specimens were fabricated using a teflon mold into which the uncured soft composite was packed and cured for 20 seconds from one side. The composite specimens were then stored for 24 hours in deionized water before being finished and polished using abrasive discs. A spectrophotometer was used to record the color of the polished specimens before bleaching was applied. Automix plastic syringe tips fitted in double barreled syringes were used to apply the bleaching agents onto the composite discs while the control group was kept in deionized water. An activating light was used on the light activated bleaching samples. Following bleaching color was recorded and the change in color was calculated. Regression analysis using two-way analysis of variance (ANOVA) was performed. The results showed that {u2206}E was significantly affected by 2the resin composite material3 and 2bleaching system3 in addition to their interaction. Bulkfill composite exposed to light activated bleaching exhibited the highest mean {u2206}E while conventional composite kept in deionized water, bulkfill composite kept in deionized water and conventional composite exposed to chemically activated beaching exhibited the lowest mean {u2206}E values. The bulkfill composite tested in the study showed higher {u2206}E values than conventional resin composites and the light activated bleaching resulted in higher {u2206}E values than the chemically activated bleaching