Jorgenson M W, Goodkind R J
J Prosthet Dent. 1979 Jul;42(1):96-105. doi: 10.1016/0022-3913(79)90335-4.
A total of 125 ceramo-metal samples were used representing: 1. Five different porcelain shades a. Ceramco shades A3, B2, and D3. b. Vita B2. c. Biobond B62. 2. Thicknesses of 1, 2, and 3 mm for each shade fired two times 3. Additional 2 mm samples for each shade fired five and 10 times. Each sample was analyzed by a recording spectrophotometer. Data received was converted to Munsell notation for evaluation of the dimensions of color, i.e., Hue, Chroma, and Value, as related to (1) shade differences, (2) thickness of porcelain, and (3) numbers of firings.