Procedures

Onlays

Talk to your dentist about...

Clinical urgency—What is the clinical urgency for placing an onlay or crown on my tooth? In many cases, a bonded filling or core buildup can provide lasting protection against fracture of the tooth while preserving tooth structure, at least until the expense of an onlay or crown can be planned for. Bonded fillings and core buildups can last many years.

Number of teeth—Is it necessary to treat more than one tooth? With modern dental ceramics and resins, the shade and optical properties of your natural tooth enamel can be matched very closely. Sometimes patients are encouraged to have multiple teeth treated to get the "best possible esthetic result". Frequently this isn't necessary.
Learn more: Procedures › Cosmetic restorations, one tooth

Custom shade—Ask about custom shade matching by the ceramist making the onlay or crown. It will often require an additional charge, and a trip to the ceramist's studio, but the cost is generally well worth the savings, chair time, potential discomfort, and other risks of having multiple teeth treated.

Durability—All-ceramic onlays and crowns may not be durable enough to withstand heavy biting forces on the back teeth of some patients. If you grind your teeth, and/or have a tendency to chip your teeth, consider whether a metal onlay or crown might be a better option in areas where the appearance of the tooth is not of great concern.

Agressive tooth removal—More tooth structure needs to be removed for porcelain onlays and crowns than for solid metal ones. This may increase the possibility of the tooth becoming inflamed and requiring additional procedures, like endodontic (root canal) therapy.

Long-term strategy—If the tooth to be restored is badly broken down and requires many concurrent procedures to be performed, each at additional cost to the onlay or crown fee (e.g. root canal, crown lengthening surgery, core buildup—see "Disadvantages"), the cost of treatment may approach that of removing the tooth and replacing it with a dental implant and crown. In such cases, the implant may have a better long-term prognosis. Be sure to discuss with your dentist whether you would be a good candidate for this option.
Learn more: Procedures › Dental implants

Endodontically treated teeth—Cracks in endodontically treated teeth occur with a higher frequency than they do in untreated teeth. For many years, the standard of care in dentistry has been to onlay or crown teeth that had been endodontically treated, so that the tooth would not crack. However, many studies have been done in the past dozen years to ascertain whether onlays or crowns are really necessary, or whether bonded composite resin fillings may provide adequate strength to hold an endodontically treated tooth together.

Although the decision must ultimately be based on careful consideration of many variables, including the tooth that was treated, the patient's individual habits (likes to chew ice and popcorn kernels, etc.), some guidelines for decision-making are presented on the list below.

• If the endodontically treated tooth was any of the front six teeth in either jaw, and most of the tooth is intact, it may only need the endodontic access hole to be restored with a filling.
• If the endodontically treated tooth was a bicuspid tooth, and the marginal ridges of the tooth are intact, it may only need the endodontic access hole restored with an access filling.
  Learn more: Glossary › Marginal ridge
• If the endodontically treated tooth was a molar, and both marginal ridges of the tooth have been restored, it likely needs a crown or onlay as the best long-term prevention against cracking.
• In one study, the overall survival rate of endodontically treated teeth that were restored with composite resin fillings was 90% after two years (without crowns).

There seems to be little doubt that bonded composite resin filling material can hold teeth together long enough for the patient to plan for the expense of an onlay or crown, or while other areas of the mouth are being treated.