POLYMERIC RESIN BASED COMPOSITES IN DENTISTRY -A REVIEW ARTICLE
*Vishal B. Naik, Ashish K. Jain and Tejraj M. Aminabhavi
The present review outlines the applications of polymeric composite resins in dental area. The review also highlights the recent and ongoing research trends reported in the field of dental monomer systems. The monomer systems of most that are presently used in dental practice are in the form of resin composites that are generally based on BisGMA (bis-phenol A glycidyl methacrylate), developed some 40 years ago, or even the derivatives of BisGMA. In the remaining resin composites, urethane monomers or oligomers are widely used as the basis of the monomer systems. The main deficiencies of the currently used resin composites are polymerization shrinkage and insufficient wear resistance under high masticatory forces. Both factors are highly influenced by the monomer system, and therefore, considerable efforts have been made by polymer chemists around the world to reduce or eliminate these undesirable properties. The use of fluoride releasing monomer systems, some of which are under investigation, has been suggested to mitigate the negative effects of marginal gaps formed in consequence of polymerization shrinkage. The very crux of the problem has also been approached with the synthesis of potentially low shrinkage or non-shrinking resin composites involving the well-known ring opening or cyclopolymerizable monomers. By the use of additives with a supposed chain transfer agent function, monomer systems have been formulated in the literature to improve the degree of conversion of methacrylate double bonds and mechanical properties. Many promising monomer systems have been devised, the implementation of which may be expected to improve the longevity of resin composite fillings and expand the indications for resin composite.
Keywords: Composite, resin, polymerization, shrinkage, shrinkage stress.
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