Adhesive resistance of a retainer system in perforated fiberglass posts associated with photoactivation using optical fiber: analysis of aging in human teeth with printed crowns

• Grant number: 24/13119-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: December 01, 2024
• End date: November 30, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Tarcisio Jose de Arruda Paes Junior
• Grantee: Larissa Haddad e Borro
• 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

One limitation on the cementation of prefabricated posts is resinous cementation, wherepolymerization is partially constrained by anatomical limitations in light emission. Anexperimental perforated post combined with optical fiber could increase the amount of lightreaching the deeper thirds, aiming for greater clinical success. The current study aims toevaluate in vitro and in silico the effect of combining an experimental hollow fiberglass postwith an optical fiber light device on the adhesive resistance of this retainer to root dentinwhen using resinous cements. Sixty human teeth will be used as samples, which will beprepared for the placement of a partially translucent perforated fiberglass post. The post hasan internal hollow extension with a regular diameter canal and progressive conicity, allowingthe insertion of optical fiber throughout the post and delivering more light to the apicalportion. The samples will be divided into 6 groups, with half being evaluated before cyclingand the other half after cycling. The groups will be: Pre-cycling - control with conventionalpost + conventional light-curing unit (C1), perforated post + conventional light-curing unit(PC1), and perforated post + optical fiber light device (PO1); Post-cycling - control withconventional post + conventional light-curing unit (C2), perforated post + conventional lightcuringunit (PC2), and perforated post + optical fiber light device (PO2). This evaluation willbe conducted through aging processes in a thermomechanical cycler. Additionally, stressdistribution will be determined using finite element analysis (FEA) with von Mises stress,Total Deformation, and Maximum Principal Stress analyzed using Ansys 19.3 software. Foradhesive resistance testing, a Push-out test will be performed on each root segment, and forassessing the degree of conversion of the cements in the apical, middle, and cervical thirds,the RAMAN test will be used. Additionally, energy dispersive spectroscopy (EDS) will beemployed to analyze the monomers present. The data will be subjected to descriptive andinferential statistics after checking for homogeneity and homoscedasticity to select theappropriate test.Keywords: