Marginal adaptation of composite resins

The historical development and important properties of composite resins are briefly reviewed. Experimental work has been undertaken to examine the marginal adaptation of three commerically available composite resins in 100 Class II and Class V restorations; dye penetration tests were used and measurement of the gap at the tooth/restoration interface as recorded in photographs obtained by scanning electron microscopy of replicas. In Class V restorations showing marginal leakage by dye penetration the gap at the tooth/restoration interface was in all cases greater cervically than occlusally. The results underline the uncertainly of obtaining a good marginal seal with composite resins both peripherally and along internal line angles.