Microleakage induced by polymerization shrinkage in methacrylate based dental composites continues to be a major concern for dental restoratives. Current methods for characterizing microleakage lack quantification and fail to provide a comprehensive evaluation, thus hinders the development of solutions to resuce/prevent microleakage.This work demonstrates that X-ray microcomputed tomography ( CT) can be used to examine the position and volume of composites nondestructively and precisely. Two series of samples systematically varying in volume and configuration (C-factor) were evaluated to determine how these parameters affect the polymerization shrinkage and microleakage formation, where the shrinkage was calculated based on volume changes before and after polymerization and microleakage was determined based on volume changes as a function of position.Microleakage results obtained by CT were compared to dye penetration outcomes. Detail analysis procedures for these novel approaches, as well as factors that affect the shrinkage and microleakage, such as the volume and configuration of the samples, are discussed.
Pub Type: Journals
dental composite, microcomputed, microleakage polymerization, shrinkage, tomography, x-ray