Monomeric characterization, cure efficiency and biocompatibility of bulk-fill composites containing elastomeric urethane monomers

• Grant number: 25/23115-5
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: May 01, 2026
• End date: April 30, 2027
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Mário Alexandre Coelho Sinhoreti
• Grantee: Anna Caroliny Detogni
• Supervisor: Dayane Carvalho Ramos Salles de Oliveira
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil
• Institution abroad: University of Florida, Gainesville (UF), United States
• Associated to the scholarship: 25/15878-9 - Development of bulk-fill composites containing elastomeric urethane monomers in different concentrations, BP.DR

Abstract

Aim: The objective of this study it will be to promote the chemical characterization of the elastomeric urethane monomers (Exothane 8, 9, 10, 24, 26, 32, 108, and 126) and analyse the cure efficiency and biocompatibility of bulk-fill experimental resin matrices containing the Exothane monomers in different concentrations (10, 20, 30, and 40%).Material and Methods: The chemical characterization of the elastomeric urethane monomers (Exothane) will be carried out using Fourier-transform infrared spectroscopy (ATR FT-IR), elemental analysis of carbon, hydrogen, and nitrogen (CHN), and nuclear magnetic resonance (NMR). Subsequently, 36 resin matrices will be prepared by combining the monomer type (UDMA, Exothane 8, 9, 10, 24, 26, 32, 108, and 126) with the concentration (10, 20, 30, and 40%). The degree of conversion and polymerization kinetics (n = 5) will be measured using Fourier transform infrared spectroscopy (FT-IR). Depth of cure (n = 3) will be performed according to ISO 4049:2019. For biocompatibility, cytotoxicity (n = 5) will be assessed by evaluating the viability of odontoblast-like cells (MDPC-23) cells using the MTT assay 24 h post-exposure, while genotoxicity (n = 5) will be evaluated using the Comet Assay in a fluorescent microscope (Axiovert 200M, Zeiss) according to ISO 10993-3:2014. Power analysis will be conducted to determine the sample size for each test (power = 0.8 or above) at a significant level of 0.5 (¿ = 0.2). Then, data obtained will first be tested for normality and homogeneity of variances. If the assumptions of normality are met the data will be subjected to analysis of variance (ANOVA), and mean values will be compared using Tukey's test at a significance level of 5%. (AU)