The effect of violet light and different bleaching treatments on resin composites

• Grant number: 19/20138-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): November 01, 2019
• Effective date (End): December 31, 2020
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Míriam Lacalle Turbino
• Grantee: Mariana Rossi Carneiro Gasperini
• Host Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The objective of this work will be to evaluate the effect of different bleaching treatments with or without the use of a violet LED light source on pigmented composite resins by evaluating the color change and surface roughness before and after the bleaching treatments. Resin composite specimens (Filtek Z350 XT - 3M ESPE and IPS Empress Direct - Ivoclar Vivadent) (12 mm diameter x 2 mm thickness) will be made and immersed in black tea (Matte Leão Tea, The Coca-Cola Company, Sao Paulo, Brazil) over a one-week period. After 6 days of the staining protocol, specimens will be randomly distributed in the following groups: G1 - 40% hydrogen peroxide; G2 - 40% hydrogen peroxide associated with violet light; G3 - light violet and GC - distilled water. Each specimen will be evaluated for color and roughness at the following experimental times: t0 - 24 hours after specimen preparation, t1 - after staining protocol was performed, t2 - 7 days after 1st bleaching treatment session, t3 - 7 days after the 2nd bleaching treatment session, t4 - 7 days after the 3rd bleaching treatment session and t5 - 7 days after the 4th bleaching treatment session for all proposed treatments. The analysis of the results will be performed after evaluation of data distribution and data normality and possibly analysis of variance for repeated measures and comparative Tukey analysis. To assess the possible relationship between color change and roughness change, Pearson correlation test will be performed. (AU)