Influence of delayed irradiation through different thickness of indirect restoration on curing characteristics of dual-cured resin cements

• Grant number: 19/18777-8
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: January 01, 2020
• End date: December 31, 2020
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Paulo Henrique dos Santos
• Grantee: Henrico Badaoui Strazzi Sahyon
• Supervisor: William Palin
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil
• Institution abroad: University of Birmingham, England
• Associated to the scholarship: 17/27114-7 - Effect of antioxidant agents after dental bleaching in luting of ceramic laminates, BP.DR

Abstract

The aim of this in vitro study will be to evaluate the effect of delayed irradiation on the kinetics of polymerization and flexural strength of dual-cured resin cements polymerized under different thickness of ceramic restoration. Two experimental formulations of dual-cured resin cements (Type I - based on camphorquinone/amine system or Type II - based on diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide [TPO]) will be prepared and polymerized under different thickness of ceramic (without ceramic; 2 mm or 4 mm), submitted to four irradiation modes (without photoactivation; immediate photoactivation for 40 seconds; immediate photoactivation for 10 seconds - 150 mW/cm2 + 60 seconds wait for chemistry cure + 30 seconds of photoactivation - 1000 mW/cm2; and delayed photoactivation of 5 minutes and after application of light activation for 40 seconds - 1000 mW/cm2). Polymerization kinetics will be monitored by Fourier-transform near infrared spectroscopy (FT-NIRS) in the resin cements, while flexural strength property will be determined by a universal testing machine. Data will be subjected to statistical normality tests and specific tests to verify the significance between means (p<.05). (AU)