Procedures

Onlays

Possible additional procedures

Core Buildup (See 'Fillings')

Core buildup involves removing any decay and weakened tooth structure, and rebuilding the damaged contours ("core") of the tooth with filling material, prior to covering the tooth with a crown. Pins may be necessary, especially if the core buildup material is not bonded in place with dental adhesives.

If most or all of the clinical crown of the tooth is gone, it may be necessary to place a structural post in the tooth's root canal. Doing so generally requires the tooth to be endodontically treated (i.e. to have "root canal" therapy).

Posts can either be pre-fabricated from fiberglass, stainless steel or titanium; or they can be custom cast in a laboratory from a gold alloy. Core buildups are distinguished from "basing to contour", in which a small chip or void in the tooth is filled in prior to preparing the tooth for the crown. Basing to contour does not constitute a core buildup for purposes of separately billing the procedure.

Endodontic (root canal) treatment

Preparing a tooth for an onlay or crown can result in inflammation of the tooth's pulp (the blood vessels and nerve tissue that reside inside the hollow center of the tooth). Because teeth are poorly equipped to deal with inflammation, the resulting inflammation may not resolve on its own without intervention in the form of endodontic treatment. Teeth that are badly broken down or extensively decayed may also become infected, requiring endodontic treatment to eliminate the infection.

A tooth which has been prepared for an onlay or crown may need endodontic treatment at any time—before, around the time of, or long after the onlay or crown is placed. Whether a tooth will need this treatment depends on many factors, including the extent of the damage/decay to the tooth and the age, health status, and tooth habits (e.g. grinding the teeth, chewing ice, etc.) of the patient.

Crown Lengthening Surgery (See 'Periodontics, surgical')

If an insufficient amount of the tooth is left protruding through the gums to hold onto an onlay or crown; or if the interface between the onlay/crown and tooth (the "margin") would need to be located far below the gums near the bone level, the tooth may require crown lengthening surgery.

Traditionally, the procedure involves elevating the gums back from the tooth, exposing the underlying bone, removing a few millimeters of bone around the tooth, and re-positioning the gums over the newly re-contoured "alveolar" (or tooth-supporting) bone. There are other ways of exposing more tooth, including surgically or orthodontically extruding it by a few millimeters. The result is that the tooth protrudes out of the gums far enough to prepare it for a solid onlay or crown with margins appropriately away from the bone.