Microstructural Features of Current Resin Composite Materials

Dental resin composites have become the primary choice of most practitioners for the direct restoration of teeth owing to their esthetics and properties, both of which are highly dependent upon the microstructure of the materials. The type, size, amount, and distribution of the reinforcing fillers are all critical determinants of the optical and physical properties of the composite. The chemistry of the resin monomers and the quality of the highly cross-linked network formed during the polymerization reaction significantly influences these properties. Finally, the transfer of stress from the weaker resin matrix to the stronger and stiffer reinforcing fillers is accomplished by ensuring a strong interfacial linkage between the two phases, typically via a silane coupling agent. Recent work characterizing and describing the influence of the microstructure of dental composites on their properties and performance are reviewed in this manuscript.