Ceramic Block의 색채측정치에 대한 Polishing과 Glazing의 영향

Abstract

To evaluate quantitatively the shade of ceramic blocks used in denial CAD/CAM system, 10 specimens (2 mm thickness) per each shade of Vita monochromatic feldspathic blocks were prepared from 7 different shades (Via Cerec Mark Ⅱ: #A1, A2, A3, A3.5, & B3, Vila Celay Blank : #A2, &A3). Before and after polishing or glazing, by use of standard C illumination of tristimulus colorimeter (Chroma Meter CR-321, Minolta Co., Japan), L*, a*, b* value and color difference (∆E') were measured on standard photographic 18% gray card (Eastman-Kodak, Rochester, NY) in dark room. Polishing and glazing were done by use of Soflex Finishing/polishing System(3M Dental Products, St Paul, MN, USA) and glaze of Vita Shading Pasie (sp15, Vita Zahnfabrik H. Rauter GmbH & Co. KG, Sackingen, Germany). The results were as follows : .I. With the increase of shade number of ceramic blocks, L* values decreased and a* and b* values increased. (p<0.05) 2. L* values of Celay Blanks were lower than those of Vita Cerec MarkⅡ blocks of the same shade. (p<0.01) 3, After polishing or glazing, L* values of ceramic blocks decreased. (p<0.01) 4, Polishing made ceramic blocks more yellow and green, but glazing had little effect on a* and b* values. 5. Because of higher ∆E*, shade changes after polishing could be easily perceived by naked eye, but those after glazing could not.