The term "crown" is used to describe the portion of your tooth that extends above the gumline - in other words, the portion of the tooth that can be seen in a healthy mouth. It is also used more colloquially to describe the dental procedure of having a prosthetic "crown" placed over a decayed, chipped, cracked, or otherwise damaged tooth.
With this dental procedure code, the prosthetic crown is seated atop an abutment, which itself is attached to a dental implant. In this specific code, the crown can either be screwed or cemented to the abutment and is made of predominately base metal. A crown that includes noble metal is designated as such because 25%-60% of its composition is of the noble metals gold, platinum, palladium, and silver. Noble metals are known to interact with human tissue well, and hold up to corrosion and oxidation better than other metals. The higher the percentage of noble metals, the less likely a crown is to corrode or oxidize, as is the case with this dental procedure code: a full crown, with high noble metal.
Use of a full, noble metal crown, as with this dental procedure code, is done when the strength and longevity of the crown are critical, and when repair is needed outside the "smile zone," as with back molars.
Since the procedure for an abutment supported crown involves the placement of a dental implant, you may wish to read the related content concerning endosteal implants, abutments, or eposteal implants for the most complete picture of this procedure. Additionally, for some crown procedures, an abutment is not used, and the crown is screwed directly atop the implant.