Composite materials are the combination of two materials. The result is a material that is <br />superior to either component alone.<br />Dental composites<br />Dental composites are supplied in a variety of shades (colors) and handling characteristics. <br />Their use continues to expand and replace other materials. Before dental composites were <br />introduced, other esthetic materials were used, such as acrylic resins, but they lacked clinical <br />efficacy. Acrylic resin materials had a high coefficient of thermal expansion, and <br />polymerization shrinkage was excessive. Recurrent caries around and under acrylic resin <br />restorations was typical. Silicate cements were also used as an esthetic material, but they <br />dissolved too quickly and required frequent replacement. In the 1960s, when dental composites <br />were developed, they quickly replaced acrylic resin and silicate restorative materials.<br /><br />New term in composite restoration<br />Universal or all-purpose composite resins<br />Given the need for a highly polishable composite resin with optimal physical properties for use <br />in the anterior and posterior regions, manufacturers developed microhybrid composite resins. <br />They reduced the particle size, ranging from 0.04 µm to 1 µm . By incorporating smaller <br />particles, microhybrid composites polish and handle better than their hybrid counterparts. <br />Microhybrid composites are stronger than most microfilled composites and can be used in both <br />anterior and posterior teeth. <br /><br />The evolution in the development and improvements with composite resins has changed the <br />way dentists practice restorative dentistry. Currently, the new generations of composite resins <br />offer excellent performance materials for anterior and posterior direct placement restorations. <br />When selecting composite resins, the criteria should include highly esthetic shade matching, <br />translucency, and fluorescence; high polishability; excellent mechanical properties that <br />contribute to restoration durability; good handling properties; excellent wear resistance; <br />radiopacity; low polymerization shrinkage; and biocompatibility. The criteria for future <br />development and introduction of new composite resins point to the progression to one universal <br />composite.20 This is a difficult challenge to manufacturer and clinician alike. To date, in <br />general, the microhybrid and nanofilled composites offer an alternative to microfilled <br />composites in their ability to be highly polishable with toothlike translucency. This class of <br />composites would be considered universal-use composite resins. Clinicians can expect excellent <br />mechanical properties, excellent esthetics with shade selection, good color stability, stain <br />resistance, low wear, and good polishability when using these composites.<br /><br /><br />References:<br />- Science of Dental Materials- Phillip Anusavice 2013<br />- Clinical Aspects of Dental Materials, 4E (2013)<br />- Article - Direct Composite Resins- Luis Guilherme Sensi, DDS, MS, PhD; Howard E. <br />Strassler, DMD; and William Webley