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Influence of different types of light curing and photoinitiators on hardness and color of resin composites

Grant number: 14/24478-0
Support type:Scholarships in Brazil - Scientific Initiation
Effective date (Start): January 01, 2015
Effective date (End): November 30, 2015
Field of knowledge:Health Sciences - Dentistry - Dental Materials
Principal Investigator:Ticiane Cestari Fagundes
Grantee:Morganna Borges de Almeida Souza
Home Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Recently, a new generation of LED was released in the dental market called third generation LED devices with multiple wavelengths. Therefore, the objective of this study will be to evaluate the microhardness and color of resin composites for bleached teeth, using two types of LED before and after immersion in drink with dye and artificial accelerated aging. Two resin composites that have in their composition the photoinitiator lucirin-TPO will be selected: Tetric N-Ceram (Ivoclar Vivadent, color A1) and Vit-l-escence (Ultradent, color WO). Filtek Z250 (3M ESPE, color B0.5). A resin composite which uses the photoinitiator camphorquinone will be used as a negative control. One hundred and twenty disc shaped specimens will be made with dimensions of 5 mm in diameter and 1.5mm thick. Half of the disks will be photopolymerized by an LED apparatus of one wavelength (Radii, SDI) and the remnants will be photopolymerized with a LED with several wavelengths (Valo Ultradent). Initial assessments of microhardness and color will be made. The specimens will be exposed to two challenges: immersion in wine or artificial accelerated aging. Then, the microhardness and color will be performed again. The mean values of microhardness and color (”E) will be evaluated by analysis of variance (ANOVA). Fisher's test for multiple comparisons will be used. The significance level used will be 5%.