Hindawi Publishing Corporation International Journal of Dentistry Volume 2012, Article ID 708032, 5 pages doi:10.1155/2012/708032 Research Article Relationship between Color and Translucency of Multishaded Dental Composite Resins Homan Naeimi Akbar, Keyvan Moharamzadeh, Duncan J. Wood, and Richard Van Noort School of Clinical Dentistry, University of Sheﬃeld, Claremont Crescent, Sheﬃeld S10 2TA, UK Correspondence should be addressed to Keyvan Moharamzadeh, k.moharamzadeh@sheﬃeld.ac.uk Received 20 August 2011; Revised 21 October 2011; Accepted 25 October 2011 Academic Editor: Andreas Stavropoulos Copyright © 2012 Homan Naeimi Akbar et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The aim of the present study was to compare the translucency of diﬀerent shades of two highly aesthetic multilayered restorative composite resins. In total nine shades from Esthet.X and ten shades from Filtek Supreme composite resins were chosen. Discs of each shade were prepared (N = 3) and light-cured. Total and diﬀuse transmittance values for each sample were measured. Statistical analysis showed that the opaque dentine shades of both composites were the least translucent and the enamel shades had the highest translucency. There was a signiﬁcant decrease in translucency from A2 to C2 of regular body shades and also from A4 to C4 of opaque dentine shades of Esthet.X composite resin. Grey enamel shade had a signiﬁcantly higher diﬀuse translucency compared to clear and yellow enamel shades. There was a signiﬁcant decrease in translucency from A2B to D2B and also in diﬀuse translucency from A4D to C6D shades of Filtek Supreme composite resin. It can be concluded that the color of the composite resins tested in this study had a signiﬁcant eﬀect on their translucency. Information on the translucency of diﬀerent shades of composite resins can be very useful for the clinicians in achieving optimal esthetic restorative outcome. 1. Introduction Understanding and correct analysis of the optical properties of the natural dentition such as color and translucency and the diﬀerences between the natural teeth and restorative materials are very important in accurate and consistent shade selection and the proper use of restorative materials in order to achieve clinical success [1–3]. There are a number of parameters aﬀecting the translu- cency of composite restorations such as thickness [4], ﬁller particles and opaciﬁers [5], and resin matrix composition [6]. Several investigators have evaluated the translucency of dental composite resins [7–13] and the inﬂuence of diﬀerent other factors on the translucency such as ﬂowability [11], light curing [14, 15], resin polymerization, and aging [16– 20]. The relationship between color and translucency of den- tal composite resins has been the focus of research in the recent decade [21, 22]. It has been demonstrated that more chromatic shades of commercial resin composites are less translucent [23].Yu and Lee measured and classiﬁed the translucency of varied brands and shades of resin composites. The results of their study showed that the translucency was signiﬁcantly inﬂuenced by the shade designation of resin composites. Recently, it has been reported that the color of several esthetic composite resins signiﬁcantly aﬀected their translucency to such an extent that the boundaries between the shade categories were not distinct, and there were some overlaps between the enamel and body shades [24]. The aim of this study was to compare the translucencies of diﬀerent shades of two commercially available highly aes- thetic multilayered restorative composite resins to establish whether there is a logical pattern to the translucency of multilayered composite resins which can be consistent with their color. 2. Materials and Methods 2.1. Materials. Two commercially available multilayered dental composite resin systems were tested in this study: Filtek Supreme (3M ESPE, USA) and Esthet.X (Dentsply, Germany).