A crown is a type of dental restoration which completely caps or encircles a tooth or dental implant. Crowns are often needed when a large cavity threatens the ongoing health of a tooth. They are typically bonded to the tooth using dental cement. Crowns can be made from many materials, like aluminia, zirconia or Porcelain-fused-to-metal dental crowns (PFMs) have a metal shell on which is fused a veneer of porcelain in a high heat oven.
Surveyed crown Another situation in which a crown is the restoration of choice is when a tooth is intended as an abutment tooth for a removable partial denture, but is initially unfavorable for such a task. If the abutment teeth onto which the RPD is supposed to clasp do not possess the proper dimensions or features required, these aspects can be built into what is known as a surveyed crown.
A temporary crown is a provisional, short term restoration used in dentistry. Usually the temporary crown is constructed from a chemical-cure composite, although alternative systems using aluminum crown forms are occasionally used by practitioners. The temporary material is shaped by the dentist to form a tooth shape that protects the prepared tooth, prevents damage to the periodontal tissues (gums) and disguises the prepared tooth to a degree until the final, definitive restoration can be made by a dental technician.
A dental implant is a "root" device, usually made of titanium, used in dentistry to support restorations that resemble a tooth or group of teeth to replace missing teeth. Virtually all dental implants placed today are root-form endosseous implants, i.e., they appear similar to an actual tooth root (and thus possess a "root-form") and are placed within the bone. The bone of the jaw accepts and osseointegrates with the titanium post. Osseointegration refers to the fusion of the implant surface with the surrounding bone. Dental implants will fuse with bone; however, they lack the periodontal ligament, so they will feel slightly different from natural teeth during chewing.