effect of coping materials and designs to the marginal adaptation of metal porcelain crowns

Abstract

The Metal porcelain crowns are still widely used because of the clinically satisfactory mechanical, esthetic, marginal and internal adaptation properties and affordable, but metal collars on the marginal labial are not aesthetically acceptable because of dark shadows in the cervical region which can be overcome by marginal porcelain butt joint coping design on the marginal labial. Recent clinical studies have introduced a type of cobalt chromium coping material that is biologically more biocompatible than nickel chromium which can cause allergic reactions. In this study, Ni-Cr and Co-Cr coping materials were used with full metal collarless and modified metal collarless coping designs. The purpose of this study was to determine the effect of material and coping design on the marginal adaptation of metal porcelain crowns. This type of research is experimental laboratory. The typodontic central incisor teeth were prepared and duplicated using CAD/CAM to become zirconia and implanted in acrylic resin blocks for the manufacture of 24 porcelain metal samples. The application of an opaque layer on both coping designs was burned at 975˚C followed by the application of dentin, enamel and glazing.