Will an onlay work for a cracked second molar?

I had an old filling in a lower left second molar. The filling cracked 2 or 3 months ago, and the tooth broke in mid-September. My dentist tried to repair the crack, but I still cannot put pressure on the outside of the tooth without feeling intense pain. Now my dentist wants to try an onlay. I prefer not to go through trial and error with the tooth. Will an onlay work, or will I need a crown? I am thinking about calling another dentist for an emergency appointment just to see what they recommend. Thanks for your input. Alok from Seattle

Alok,

Thank you for your question.

Dr. Thomas would need to examine your tooth and x-rays to determine the type and extent of the tooth crack. The location of the tooth crack can also affect the treatment options. But your question is about onlays, so without suggesting a diagnosis or explaining treatment options, we will discuss onlays.

Dental Onlays

A dental onlay is a ceramic restoration covering one or more cusps or peaks of a tooth. Some onlays work well for tooth cracks, but others have restrictions. A dentist’s goal is to stabilize and repair a crack to prevent a tooth from fracturing.

Onlay advantages

A dental onlay has several advantages over a dental crown.

Preserves more tooth structure – A dental crown requires shaving down your tooth on every side. But an onlay removes only the damaged portion of a tooth.

• Promotes gum health – An only does not extend below the gumline and is healthier for gum tissue than a crown.
• Versatile materials – A dentist or lab can make onlays of gold, ceramic, or hardened composite. The options for materials are adaptable depending on your needs.
• Gold is durable – A gold restoration is more durable than ceramic and would protect virtually any cracked tooth.
• Ceramic or porcelain has limitations – Although they make beautiful onlays, ceramic or porcelain may not be strong enough to hold a severe vertical crack. The ceramic and tooth are at risk of cracking.
• Hardened composite has limited longevity – Composite may work for a basic onlay but is not strong enough for a cracked tooth.

Repairing a Cracked Second Molar

Most dentists would repair a cracked tooth with a ceramic or gold crown. But others skilled in ceramics and onlays understand the techniques required to preserve your tooth with an onlay. We recommended asking your dentist how many cases like yours they have resolved with an onlay. Ask to see before-and-after photos, and ask about the current status of the patients’ onlay.

If you are unsure of your dentist’s recommendation, we recommend getting a second opinion from an advanced cosmetic dentist. Although you can make an emergency appointment with another dentist, the second opinion may not be worthwhile unless they have advanced cosmetic dentistry training. Even so, the dentist would need to examine your x-rays—or take new ones—for an accurate diagnosis.

Best wishes for a healthy resolution.

Dr. Siny Thomas of Sugarland, Texas, sponsors this post. He is a graduate of the Kois Center for cosmetic and restorative dentistry.