Color stability and surface degradation of bioactive resin composites after exposure to organic solvents

Abstract

Organic solvents are used in vitro as solutions that simulate the effects of products on the properties of different materials. Thus, the aim of the present study will be to evaluate the effects of exposure to the solvents methylethyl ketone (MEK) and heptane on color and surface roughness of bioactive composite resins. Cylindrical specimens (6mm in diameter and 2 mm in thickness) of composite resins (n=12): conventional nano-hybrid (Shape, Ultradent); nano-hybrid with S-PRG (Beautifil II LS, Shofu) and bioactive (Cention N, Ivoclar) particles. The samples will be analyzed for surface roughness (Ra) (Surftest SJ-210, Japan) and quantified in color coordinates (Cie L*a*b*) and general color change values (”Eab, ”E00) by reflectance spectrophotometry analysis (CM 700d, Minolta). The color and roughness analyses will be performed at the following times: initial (baseline) and after immersion in the distilled water,MEK or heptane, for 7 days. At the end, the surface of the materials will be evaluated in scanning electron microscopy (SEM), at 1000× and 2000× magnification. The data will be submitted to the normality and homoscedasticity test for subsequent application of parametric or non-parametric tests, with a significance limit of 5% (±=0.05).