CDEN0110

34 I I industry report _ composite resin _Experience has shown that aesthetically pleasing composite restorations in the anterior region can only be created, if the clinician suc- ceeds in achieving a near-perfect shade match between the restorative material and remaining dentition. In general, state-of-the-art compos- ite restoratives should be easy to handle, adapt to cavity walls and offer good surface finishing qualities. At the same time, however, it is essen- tial that they allow the restoration to blend har- moniously into the natural oral environment. Aesthetic integration is accomplished by placing special optical effects. Composite ma- terials with a high opacity (similar to dentine) and relative translucency (similar to enamel) are required for this. Composite restorative systems that additionally include an opalescent material thatallowsthebluishareas(frequentlyobserved along the marginal ridges) and yellowish- whitish portion of incisal edges to be reliably mimicked, offer just about everything the clin- ician needs to restore a case aesthetically. The new IPS Empress Direct system (Ivoclar Vivadent) includes such an opalescent material, which enables the reproduction of the above- mentioned optical phenomena owing to its shade effects. Opalescence is an optical effect exhibited by somesubstances.Itiscausedbytherefractionof the various wavelengths of visible light due to the small structures in the substance. As a result, the substance exhibits an intensive bluish tinge in incident light, whereas it has milky yellowish appearance in transmitted light, just as is the case in natural opal stone. In restorations, the light that strikes the composite material and is reflected from it appears bluish. Against the light,however,thecompositehasaslightlymilky appearance with a yellowish tinge. The incisal edge of natural dentition often has this ap- pearance. The clinical case described here involved the replacement of two defective proximal restora- tions (Fig. 1). An initial analysis of the various shade layers of which the natural teeth were cosmeticdentistry 1_2010 Opalescent composite resin Author_ Ulf Krueger-Janson, Germany Fig. 1_Initial findings: defective restorations in teeth 11 and 21. Fig. 2_Incisal view. Fig. 3_View after removal of the old fillings. Fig. 3 Fig. 1 Fig. 2