Fixed prosthodontics

Fixed prosthodontics is the area of prosthodontics focused on permanently attached (fixed) dental prostheses. Such dental restorations, also referred to as indirect restorations, include crowns, bridges (fixed dentures), inlays, onlays, and veneers. Prosthodontists are specialist dentists who have undertaken training recognized by academic institutions in this field. Fixed prosthodontics can be used to restore single or multiple teeth, spanning areas where teeth have been lost. In general, the main advantages of fixed prosthodontics when compared to direct restorations is the superior strength when used in large restorations, and the ability to create an aesthetic looking tooth. As with any dental restoration, principles used to determine the appropriate restoration involves consideration of the materials to be used, extent of tooth destruction, orientation and location of tooth, and condition of neighboring teeth.

Preparation of a tooth for a crown involves the irreversible removal of a significant amount of tooth structure. All restorations possess compromised structural and functional integrity when compared to healthy, natural tooth structure. Thus, if not indicated as desirable by an oral health-care professional, the crowning of a tooth would most likely be contraindicated. It should be evident, though, that dentists trained at different institutions in different eras and in different countries might very well possess different methods of treatment planning and case selection, resulting is somewhat diverse recommendations for treatment.

Traditionally more than one visit is required to complete crown and bridge work, and the additional time required for the procedure can be a disadvantage; the increased benefits of such a restoration, however, will generally offset these considerations.

When preparing a tooth for a crown, the preparation should, ideally, exist entirely in enamel. As elaborated on below, the amount of tooth structure required to be removed will depend on the material(s) being used to restore the tooth. If the tooth is to be restored with a full gold crown, the restoration need only be .5 mm in thickness (as gold is very strong), and therefore, a minimum of only .5 mm of space needs to be made for the crown to be placed. If porcelain is to be applied to the gold crown, an additional minimum of 1 mm of tooth structure needs to be removed to allow for a sufficient thickness of the porcelain to be applied, thus bringing the total tooth reduction to minimally 1.5 mm. For porcelin or ceramic crowns the amount of tooth reduction is 2 mm. For metal it is 1 mm.

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Wikipedia