Understanding the kinetics and network formation of dimethacrylate dental resins

Dimethacrylate monomers are commonly used as the organic phase of dental re storative materials but many questions remain about the underlying kinetics and network formation in these highly crosslinked photopolymer systems. Se veral novel experimental and modeling techniques that have been developed f or other multifunctional (meth)acrylates were utilized to gain further insi ght into these resin systems. Specifically this work investigates the copol ymerization behavior of bis- GMA (2, 2-bis [p-(2-hydroxy-3 -methacryloxypro p-loxy)-phenyl]propane)and TEGDMA (triethylene glycol dimethacrylate), two monomers typically used for dental resin formulations. Near-infrared spectr oscopy, electron paramagnetic resonance spectroscopy, as well as dynamic me chanical and dielectric analysis were used to characterize the kinetics, ra dical populations, and structural properties of this copolymer system. In a ddition, a kinetic model is described that provides valuable information ab out the network evolution during the formation of this crosslinked polymer. The results of these numerous studies illustrate that all of the aforement ioned techniques can be readily applied to dental resin systems and consequ ently can be used to obtain a wealth of information about these systems. Th e application of these techniques provides insight into the complex polymer ization kinetics and corresponding network formation, and as a result, a mo re complete understanding of the anomolous behaviors exhibited by these sys tems, such as diffusion controlled kinetics and conversion dependent networ k formation, is attained. Copyright (C) 2001 John Wiley & Sons, Ltd.