The purpose of this study was to investigate the effect of the fracture strengh and color of ceramic by the design of the metal coping in ceramo metal crown. In this study, four types of ceramic crowns were made for fracture strength : standard ceramo metal crown, collariess ceramo metal crown, modified ceramo metal crown, and ceramic jacket crown. And three types of disk formed - specimens were made to compare the dentin shade owing to aluminous opaque powder and palladium alloy. Fracture strength was measured by universal testing machine(Instron Co. Ltd., U.S.A) and color was measured by color and color difference meter(Yasuda Seiki Seisakusho, Ltd., Japan). @ES The results were as follows :
@EN 1. The fracture strength of ceramic was affected significantly by the design of metal coping in ceramo metal crown. The mean fracture strength(192.0 Kg) of standard ceramo metal crown was about 1.7 times higher than that(111.5 Kg) of collarless ceramo meal crown, and about 2.8 times higher than that(67.8 Kg) of ceramic jacket crown. 2. Modified ceramo metal crown that has metal band in the labio cervical had the lowest fracture strength. 3. Lightness, yellowness and redness of the dentin fired were decreased by the metal coping.
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