Determination Of Polymerization Shrinkage Stress Of Composite Resins By Means Of A Photo-elastic Analysis

With the successful improvement in adhesiveness, resin-based restorative materials are used widely in clinic. Compared with dental amalgam materials, it has the advantages of matching the shade of natural teeth, being mercury-free and non-conductive, but has the most critical disadvantage of polymerization shrinkage. The material shrink during the radical polymerization reaction, and contraction stress occurs when the material is rigid enough to resist sufficient plastic flow to compensate for the original volume. The shrinkage stress may adversely affects the maintenance of the bonded interface between composite and dental hard tissues, and can potentially cause debonding and lead to clinical failure of the restorations, which may result in microleakage of fluids, staining of marginal gaps and recurrent caries. This study examine the polymerization stress of different composite resins by means of a photo-elastic methods to better understand the development of shrinkage stress and the way to reduce it.1. Evaluation of the microtensile bond strength between resin composite and epoxy resin...