Typical commercial restorative dental compositions in the form of medical resins contain in-organic fillers, multifunctional methacrylates and photoinitiators. The currently used resins for direct composite restoratives have been mainly based on acrylic chemistry to this day. The main problem with the application and radiation curing process is the shrinkage of photoreactive dental materials during and after UV curing. Shrinkage of restorative radiation curable dental composites is a phenomenon of polymerization shrinkage, typical behavior of multifunctional methacrylates during the polymerization process. The important factors in curing of dental composites are: the kind and concentration of the used methacrylate, its functionality, double bond concentration, the kind and concentration of the added photoinitiator and UV dose emitted by the UV-lamp. They are investigated multifunctional 1,3-butanediol dimethacrylate (1,3-BDDMA), diethylene glycol dimethacrylate (DEGDMA), triethylene glycol dimethacrylate (TEGDMA), trimethylolpropane trimethacrylate (TMPTMA), 2,2-bis-[4-(2-hydroxy-3-methacryxloyloxypropyl) phenyl]propane (Bis-GMA), ethoxylated Bis-GMA (EBPDMA) and dodecandiol dimethacrylate (DDDMA). Reduction of polymerization shrinkage of restorative dental compositions is at the moment a major problem of dental technology. This problem can be solved through an application of photoreactive non-tacky multifunctional methacrylates in the investigated dental adhesive fillings.
Polymerization shrinkage of cured dental composites with different resin matrices
