Accession Number : ADA139601

Title :   Masking Power of Dental Opaque Porcelains.

Descriptive Note : Rept. for Jun 79-Jun 81,

Corporate Author : ARMY INST OF DENTAL RESEARCH WASHINGTON DC

Personal Author(s) : Woolsey,G. D. ; Johnston,W. M. ; O'Brien,W. J.

Report Date : 02 DEC 1983

Pagination or Media Count : 18

Abstract : Optimum thickness of opaque porcelain over gold flash coatings has been found to be less than that over oxidized metal surfaces. The purposes of this study was to evaluate the relative opacity or masking power of five brands of dental opaque porcelain. Five shades of dental porcelain opaque from the following manufacturers: Ceramco, Biobond, Will-Ceram, Neydium, and Vita VMK-68 were evaluated. The difficulty of evaluating dental porcelain opaque by reflectance spectrophotometry, required the use of dental porcelain glaze as a diluting agent. Ten and twenty percent dilutions of each opaque were examined in the spectrum from 410-700nm. The optical infinite thickness of each dilute dental porcelain opaque was calculated from reflectance data using the Kubelka-Munk equation. Using Scheffe multiple comparisons, significant differences (P=0.05) in optical infinite thickness or relative masking power were found for each of the Bioform shades studied. Ceramco Paint-O-Pake was found to have the lowest value of optical infinite thickness for four of the five shades; for the fifth, Ceramco was statistically equal to the other brands. Neydium 'B' and Biobond were found to be intermediate in optical infinite thickness. Will-Ceram and Vita VMK-68 were found to have the highest optical thickness values of the brands evaluated.

Descriptors :   *Dental equipment, *Ceramic materials, Opacity, Oxides, Reflection, Thickness

Subject Categories : Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE