Translucency of Ceramic Materials for CEREC CAD/CAM System ALESSANDRO VICHI, DDS, MS, PhD*, MICHELE CARRABBA, DDS † , RADE PARAVINA, DDS, MS, PhD ‡ , MARCO FERRARI, MD, DDS, PhD § ABSTRACT Objectives: To compare translucency of the ceramic materials (CEREC CAD/CAM). Materials and Methods: Fifteen ceramic materials for CEREC CAD/CAM system were evaluated: IPS e.max HT/LT/MO, ZirCAD, Empress HT/LT; VITA Mark II, VITA AL; VITAYZ, VITA In-Ceram Spinell/Alumina/Zirconia; and Sirona InCoris AL; Sirona InCoris ZI/TZI. Specimens (0.5-mm and 1.0-mm thick; n = 10 each material) were cut from commercial blocks using a water-cooled diamond saw. Contrast ratio (CR = YB/YW) was measured using a spectrophotometer with an integrating sphere. Kruskal–Wallis one way analysis of variance was performed followed by Dunn’s multiple test for post-hoc. Results: CR varied from 0.35 to 1.00 and from 0.48 to 1.00 for 0.5 mm and 1.0 mm thicknesses, respectively. CR increased in the following order: IPS e.max HT (most translucent—least opaque), IPS Empress HT, VITA Mark II, IPS Empress LT, IPS e.max LT, In-Ceram Spinell, IPS e.max MO, VITA YZ, InCoris TZI, IPS e.max ZirCAD, InCoris ZI, In-Ceram Alumina, VITA AL, InCoris AL, and In-Ceram Zirconia (least translucent—most opaque). Conclusions: The null hypothesis has been rejected because tested materials exhibited a wide range of CR. Translucency needs to be taken into account in different clinical situations, including considerations associated with thickness of restoration and/or particular layers. CLINICAL SIGNIFICANCE A wide range of translucency was identified for the ceramic materials tested. This variability has to be taken into account for the selection of the materials in different clinical situations also related to the thickness clinically required. (J Esthet Restor Dent ••:••–••, 2014) INTRODUCTION Porcelain fused to metal restorations (PFM), combining resistance and esthetics, have been considered the reference procedure for fixed dental prosthetic restorations for a long time. However, the metal substructure prevents the transmission of light, thus diminishing the probability of fully mimicking optical properties of natural teeth. 1 To overcome this esthetic limitation, a variety of metal-free materials and techniques have been introduced, including the development of CAD/CAM technology, nowadays supported by scientific evidence of clinically adequate performance. 2,3 The CAD/CAM system CEREC (Sirona, Bernsheim, Germany) has been created in the mid-1980s with the aim of manufacturing a dental ceramic restoration within the same day 4 or even preferably in a single appointment (so called “chairside” *Research Professor, Department of Medical Biotechnologies, University of Siena, Siena, Italy † PhD Student, Department of Medical Biotechnologies, University of Siena, Siena, Italy ‡ Professor, Department of Restorative Dentistry and Prosthodontics, The University of Texas Health Science Center School of Dentistry, Houston, TX, USA § Professor and Chair, Department of Medical Biotechnologies, University of Siena, Siena, Italy RESEARCH ARTICLE © 2014 Wiley Periodicals, Inc. DOI 10.1111/jerd.12105 Journal of Esthetic and Restorative Dentistry Vol •• • No •• • ••–•• • 2014 1