The ceramic-metallic crown is a fixed prosthesis in the shape of a tooth, fixed on the original tooth previously prepared.
The main advantages of a metal-ceramic or emax crown are :
Its biocompatibility: no appearance of gray lines in time because there is no metal, harmlessness with the oral cavity in opposition to the ceramic-metal crowns.
Its resistance: it is all resistant.
Its aesthetics: it is best suited to support a ceramic dental crown.