Ceramometal crowns and bridges. Focus on failures.

There are numerous factors that can have an adverse or beneficial effect upon the esthetic appearance of a ceramometal restoration. Some of these factors are beyond the influence of the dentist unless he or she is aware of them. As knowledgable practicing dentists, they have the ability to prescribe for their patients in such a manner as to achieve greater success and, in turn, greater patient acceptance and recognition. These are the rewards of a successful crown and bridge practice, and the ceramometal restoration is the basic state of the art prosthesis in present use. Knowing how to take a shade under the proper lighting conditions is generally well taught as part of the dental school curriculum, but the knowledge that shade guides are manufactured with built in idiosyncrasies of color variations from guide to guide is an enlightening experience. O'Brien of the Department of Dental Materials at the University of Michigan School of Dentistry clearly demonstrated the variabilities of color intensities between porcelain manufacturers. Laboratory technicians have been frustrated by the inconsistency of shades of porcelains from one lot number to another. It is now more fully understood that fluorescence is an important factor in patient satisfaction, as patients observe and have their restorations seen under differing lighting conditions. The type of alloy used in the ceramometal combination can have an effect upon the esthetic result. The wider use of silver-palladium alloys requires that the porcelain employed be of a nongreening nature, or else the final glazed prosthesis will give off a greenish cast. The ability of the opaque to block out the metal substructure while blending with the gingival and incisal shades eliminates the graying out, which can be esthetically objectionable to the patient. However, one of the most important considerations in aesthetic ceramometal restorations is the correct anatomy, placement, and harmonious blending with the oral and facial features and coloring of the patient. It would be comforting if we could all agree on a definition of esthetics. There is perhaps no more important aspect of marketing the ceramometal restoration to the patient than arrive, in advance, on a common ground and understanding of what the esthetic goals of the case are in realistic terms.(ABSTRACT TRUNCATED AT 400 WORDS)