Crowns and Onlays

You likely have heard the term “crown” related to dental work. Crowns, in simple terms, are a cap or cover that protects a damaged tooth.

When a tooth’s structure is compromised by large decay or a crack, a crown may be the best way to restore it to its proper shape and function. A crown is usually made of a strong ceramic material, or in some cases, gold. It typically takes two appointments to complete the process of getting a crown. At the first appointment, the tooth is prepared to make room for the crown, and an impression is taken and sent to a dental lab to have your expertly crafted, custom crown fabricated. You will have a temporary crown to wear for about a week until the next appointment. At the next appointment the crown is tried in, and if we are both happy with the result, the crown is permanently bonded to the tooth. Your crown is set, and your tooth is restored to its natural shape and function.

Onlays are lesser known than crowns but play an important role in the right circumstances. An onlay can be used to restore a tooth when a larger or more extensive crown is not required. If a crown is like a cap or a cover for the tooth, think of an onlay as a strong ceramic tile covering the chewing surface.

An onlay saves as much of the natural tooth structure as possible while providing strength and function to the tooth. Your dentist will prepare the tooth minimally, removing only the damaged or decayed areas to create enough room for the onlay. The tooth surface is further modified with bonding and composite to increase the strength of the adhesive. An impression is made and a temporary cover is placed while your onlay is being crafted by the dental lab. After about a week, your onlay is checked for fit and bonded to the tooth. Your tooth is restored to its natural structure and function – and more of your natural tooth is preserved! There are many advantages to this procedure, the main one being less reduction of tooth structure, which may result in a longer life for your tooth.

When a tooth is severely damaged and there’s not enough natural tooth structure to support a restoration, a procedure called a “core build-up” is performed using composite (tooth-coloured filling) to add enough structure so the tooth can accept the crown or onlay. We will remove any weak or decayed tooth structure and then apply a layer of adhesive so the composite will maintain a durable bond with your tooth. The composite is then placed and shaped so that a ceramic crown or onlay can be placed overtop.