|Support type:||Scholarships in Brazil - Scientific Initiation|
|Effective date (Start):||July 01, 2009|
|Effective date (End):||June 30, 2010|
|Field of knowledge:||Health Sciences - Dentistry - Dental Materials|
|Principal Investigator:||Maria Teresa Atta|
|Grantee:||Camila Cruz Libardi|
|Home Institution:||Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil|
Resin composite changed greatly due to photoactivation, resulting in better properties. The possibility of reproduction of the teeth color is one of these properties, however it still is susceptible to alterations caused by extrinsic and intrinsic factors. This study aimed to evaluate the influence of light tip distance on color stability of different resin composites. The null hypothesis to be tested are: 1- There is no difference of color related to light tip distance; 2- There is no difference of color related to resin composite; 3- There is no difference of color related to initial color. Eight specimens of Filtek Z350, Filtek Z250, Esthet X and Master Fill will be tested using A1 and A3 shades in two different conditions: light-cured with a standard distance of a glass slide interposition or at 10cm distance. Following, the color of specimens will be measured according to CIElab system and will be submitted to 10-minute cycle in coca-cola alternated to artificial saliva or only in artificial saliva (control) to complete 24 hours twice a day. These cycles will be performed until 4 weeks. At the end of each week, new measurements will be done. Data will be analyzed and if they present normal distribution, they will be analyzed by ANOVA and Tukey tests (p<0.05).