Dimethacrylate based on cycloaliphatic epoxide for dental composite

Objectives The aim of this study was to investigate the kinetics and mechanical properties of dimethacrylate monomer based on cycloaliphatic epoxide for dental restorative composite. Methods Dimethacrylate based on cycloaliphatic epoxide (EPCDMA) was copolymeirzed with TEGDMA by varying the curing conditions: monomer composition and light intensity. A real-time near FTIR technique was employed to monitor the double bond conversion and the rate of polymerization. Dynamic mechanical analysis was performed on a dynamic mechanical analyzer, and volume shrinkage of the cured samples was determined by pycnometric method. Results The results of kinetics showed that, two peaks of maximum rate of polymerization (Rpmax) occurred when the amount of TEGDMA was more than 30 wt%. Increasing the amount of TEGDMA, the final double bond conversion and polymerization shrinkage both increased, while the glass transition temperature (Tg) decreased. All EPCDMA/TEGDMA mixtures had slightly higher storage modulus at body temperature (37 °C). When compared with Bis-GMA/TEGDMA (70/30), the EPCDMA/TEGDMA (70/30) system assumed similar reactivity and volume shrinkage but higher Tg. Significance EPCDMA had comparable mechanical properties to those of Bis-GMA.