An investigation of potential behavior of surface colorant applied in various layers of ceramometal restoration

PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.Thesis M. Sc. D. --Boston University, Henry M. Goldman School of Graduate Dentistry, 1984 (Prosthodontics).Includes bibliographical references (leaves 55-66).Color modifications of ceramometal crowns have long been a problem for dentists, dental technologists and dental porcelain manufacturers. Surface colorants (stains) are frequently used to modify the ceramic crown colors. However, there is a paucity of information in the dental literature of scientific investigation concerning the interaction of stains when applied to various sections of ceramic crowns. The purpose of this study was to investigate the difference in behavior of stains when applied to various sections of ceramometal crowns. Three groups (total of 45 specimens) of different brands of porcelains were used. The stain was applied by the following three methods: a. The first method was application of stain at the opaque body interface and air fired b. The second method was application of stain to the external surface of the body layer and air fired c. The third method was application of stain to the external surface of the body layer, modified by burnished porcelain, and air fired. These samples were sectioned transversely and examined under a light microscope. The results were: a. When stain was applied to the opaque layer there was a significant diffusion of stain into the body porcelain layer. b. When stain was applied to the external surface of the body layer, there was no significant diffusion of the stain into the body porcelain layer. c. Additional observations revealed the following: 1. The stained layers exhibited various sized voids in the methods where stain was applied internally and externally. 2. The stained layers did not exhibit any voids when the surface was burnished with a porcelain slurry. During the course of this investigation, information was obtained relative to the variables affecting the resultant specimen fabrication and testing. The reader is encouraged to critically study the findings for possible future research