Curing Front Shape and Velocity in Cylindrical Bulk-Filled Light-Cured Resin Composite

Abstract

Clinical failures of resin composite dental restorations are common phenomena. Such failures occur in part because of the polymerization shrinkage inherent to methacrylate-based materials. Numerous efforts have been attempted to reduce the deleterious effects of polymerization shrinkage. Despite such efforts, it appears that no simple solution to the problem exists. To effectively improve bonding methods, more information must be known about the polymerization process itself. By using the Finite Element Method (FEM), an accurate computer simulation model of the polymerization process may be created. Such a model may allow researchers to test the effects of alternative restorative and bonding techniques without actual in vitro experiments. To create an accurate computer model, much information about the transient events present during the curing process has yet to be obtained. In this non-clinical, data-gathering study, we: 1) verified that the shape of the curing front within a light-cured resin composite model is indeed convex, 2) determined that the curing front shape changes with depth of cure, and 3) measured the velocity of the curing front as it relates to curing light distance. Each of these observations and measurements has yielded information vital to the subsequent development of a resin composite polymerization model. It is anticipated that necessary data regarding other variables or aspects of the polymerization process will be obtained in subsequent research projects.