Onlays and Partial Veneer Crowns
When more than half of the tooth’s biting surface is damaged a dentist will often use onlays or partial veneer crowns.
What are Onlays and Partial Veneer Crowns?
Onlays and partial veneer crowns can be made of porcelain, gold, or a composite resin. These restorations are cemented or bonded to the damaged area of the tooth. An onlay extends over and covers over one or more of the cusps of the chewing surface of the tooth; a partial veneer crown covers the chewing surface and also part of the vertical surface (sides) of the tooth, often leaving the visible or cheek side of the tooth untouched.
Traditionally, gold has been the material of choice for these restorations. In recent years, however, porcelain and zirconia have become increasingly popular due to their color which can potentially match the natural color of your teeth.
How are they made?
Onlays and partial veneer crowns require two appointments to complete the procedure. During the first visit, the filling being replaced or the damaged or decaying area of the tooth is removed and the tooth is prepared for the restoration. To ensure proper fit and bite, an impression or digital scan of the tooth is made by Dr. Fischer and sent to a lab for fabrication; he will then apply a temporary restoration on the tooth and a subsequent appointment will be scheduled.
At the second appointment, the temporary restoration is removed. Dr. Fischer will then make sure that the onlay or partial veneer crown fits correctly. If the fit is satisfactory, the restoration will be cemented to the tooth and polished for a smooth finish.
Traditional fillings can reduce the strength of a natural tooth by up to 50%. As an alternative, onlays or partial veneer crowns are cemented or bonded directly onto the tooth using special high-strength resins. With proper care, a well placed onlay or partial veneer crown may last from 10 to 30 years. In some cases, where the damage to the tooth is not extensive enough to merit an entire crown, onlays or veneer crowns can provide a very good alternative.