Analysis of the Influence of Composite Resin Indirect Restoration Thickness on Energy Transmission and Microhardness in Dual-Cure Resin Cement Polymerization

• Grant number: 23/18347-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2024
• End date: June 30, 2025
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Eduardo Bresciani
• Grantee: Sandy Vitória dos Santos Osório
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Indirect restorations can be crafted from various materials, and composite resin is highlyutilized due to its cost-effectiveness and good mechanical and aesthetic properties. The useof dual-curing resin cement is considered the gold standard for the fixation of these pieces,as the combination of chemical and light activation maximizes polymerization, an essentialcharacteristic for non-translucent and dense restorations, where light may struggle topenetrate. The propagation of light through an indirect restoration has a direct impact on theconversion of cement monomers, and furthermore, the varied thicknesses of the indirectpiece also influence light propagation. Since microhardness can be considered a parameterfor photopolymerization analysis, the objective of this study is to evaluate the influence ofthe thickness of indirect composite resin restorations on the photopolymerization of dualcuring resin cement. Sixty composite resin discs with a diameter of 12mm and variablethicknesses (1.5; 2.5 or 3.5mm) will be fabricated and assessed with dual-curing resincement using two different light-curing units to evaluate irradiance through the pieces andcement microhardness, with readings taken immediately after polymerization and again after24 hours. Descriptive statistics based on the mean and standard deviation will be performed,and inferential statistical analysis will be carried out using repeated measures analysis ofvariance (ANOVA 3 factors) with a post-hoc Tukey test if significant differences are foundamong the groups (p>0.05). In cases of non-normality, a non-parametric test will beproposed.