Abstract:

Objective　The purpose of this study was to evaluate the color masking ability of Computer Aided Design/ ComputerAided Manufacture(CAD/CAM) machining ceramic Vita Mark II, this ability was affected by thickness and shade. Methods　Each of 5 specimens of 0·5 mm, 1·0 mm and 1·5 mmVitaMark II A3C/18 and A2C/18 were prepared and the color change was measured after the substrate simulating stained teeth was covered with the specimen.Results　Statistically significant differences (P<0·01) were recorded in the substrates covered with different thickness and shade of Vita Mark II. The color changes (△E) were 15·181, 17·691, 19·667 and 15·653, 16·880, 18·002 afterthe substrateswere coveredwith 0·5 mm, 1·0 mm and 1·5 mmVitaMarkⅡA3C/18 and A2C/18.Conclusion　As a dental material, CAD/CAMVitaMark II has high quality to mask the underlying color. Being a veneer, the masking abilitywith A2C/18 is better than thatwith A3C/18, but being an in- lay, the result is reverse.

Key words: restoration material, machining ceramic, Vita Mark II, color masking ability