Abdelnabi A.E.Hamza N.K.Operative DentistryNational Research CenterEgypt; Operative DentistryMSA UniversityEgypt2020-01-092020-01-0920169758585https://t.ly/n1x1jScopusThis study was carried out to compare the color stability of two different types of resin composite after accelerated aging. Specimens of X-tra base (VOCO GmbH) bulk fill flowable composite and Grandio flow (VOCO GmbH) flowable composite were aged in a weather chamber device for 296 hours with a total energy of 300 kilojoules. Color assessments were done before and after aging. The color change was calculated from the following equation: ?E= [(?L) 2 + (?a) 2 + (?b) 2] 1/2. Results showed significant color changes for both composite types after aging with both showing nearly equal ?E values. It was concluded that the two types of tested resin composites lacked the ability to maintain their color after aging and that bulk fill flowable composite did not show any significant improvement regarding color stability. 2010 RJPBCS.Englishجامعة أكتوبر للعلوم الحديثة والآدابMSA UniversityUniversity for Modern Sciences and ArtsOctober University for Modern Sciences and ArtsBulk fillColorFlowable compositeWeather chambercamphorquinoneagingArticlebulk fill flowable compositecolorcolor stabilitycolorimetrycomparative studycomposite materialcontrolled studyconventional flowable compositeflow ratein vitro studyKolmogorov Smirnov testmathematical parameterspolymerizationspectrophotometryweatherArticle