Comparative analysis of photoinitiators in experimental resin composites: ideal concentration, polymerization characteristics, degradation, and biological compatibility.

• Grant number: 15/16569-8
• Support type: Regular Research Grants
• Duration: November 01, 2015 - April 30, 2018
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal researcher: Roberta Caroline Bruschi Alonso
• Grantee: Roberta Caroline Bruschi Alonso
• Home Institution: Pró-Reitoria Acadêmica. Universidade de Mogi das Cruzes (UMC). Campus da Sede Mogi das Cruzes. Mogi das Cruzes , SP, Brazil
• Assoc. researchers: Nilana Meza Tenório de Barros

Abstract

The aim of this study is to obtain materials with optimized physical and mechanical properties for dental application, in this way the optimal concentration of different photoinitiators in dental composites will be determined. Polymerization characteristics, degradation products and biological compatility will be evaluated. Experimental composites with different photoinitiators (camphorquinone (CQ), Phenylpropanedione (PPD) and bys-acylphosphine oxide (BAPO), with or without a co-initiator) will be tested. In phase 1 of this study, the optimal concentration of each photoinitiator will be determined by analyzing the polymerization kinetics, degree of conversion, crosslinking density, colour, hardness, depth of cure, flexural strength and modulus of elasticity of experimental composites containing different concentrations of photoinitiators (0.25%, 0.5%, 1%, 1.5% and 2%). In phase 2, for each photoinitiator, the composite with the best polymerization features and mechanical properties will be selected for evaluation of the degradation characteristics (evaluation of gap formation in restorations after thermo-mechanical cycling; sorption and solubility; determination of leachable components) and biocompatibility. Marginal and internal gap formation will be evaluated in class I cavities submitted to thermo-mechanical degradation (100,000 mechanical cycles - 2 Hz, 60N + 500 thermal cycles 5º/55ºC) using the replica technique / scanning electron microscopy analysis. Water sorption and solubility is will be determined in accordance with ISO 4049. Leachable components will be determined by high performance liquid chromatography (HPLC) + mass spectrometry in different periods (24h, 48h, 7 days, 30 days and 60 days). The biocompatibility of the composite and neat photoinitiators will be determined by the cytotoxicity test on human fibroblasts Confluent plates of wells 6-12 and / or transwell using MTT. All data will be submitted to appropriate statistical analysis at 5% significance. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ALVES MACIEL, DAYANY DA SILVA; CAIRES-FILHO, ARNALDO BONFIM; FERNANDEZ-GARCIA, MARTA; ANAUATE-NETTO, CAMILLO; BRUSCHI ALONSO, ROBERTA CAROLINE. Effect of Camphorquinone Concentration in Physical-Mechanical Properties of Experimental Flowable Resin Composites. BIOMED RESEARCH INTERNATIONAL, 2018. Web of Science Citations: 1.