Translucency of Ceramic Materials for CEREC CAD/CAM System

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; VITA YZ, 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.