Dental Onlays: When a Tooth Needs More Than an Inlay

Why Would I Need a Dental Onlay?

The amount and location of healthy tooth structure remaining are important when choosing how to restore a damaged tooth.

If a tooth needs more support than a filling or inlay can provide, but does not require full coverage with a crown, Dr. Christine Chin may consider an onlay.

An onlay may be considered when a tooth has:

What’s the Difference Between an Inlay and an Onlay?

Inlays and onlays are both custom restorations, but the key difference is how much of the tooth they cover.

An inlay generally fits within the cusps—the raised portions of the tooth’s chewing surface.

An onlay extends over one or more cusps when those areas also need to be restored or protected.

Dr. Chin determines which option is appropriate based on the location and extent of the damage and the strength of the remaining tooth. For more on inlays, read Dental Inlays: When a Filling Isn’t Enough.

What’s the Difference Between an Onlay and a Crown?

An onlay is sometimes described as a partial-coverage restoration because it repairs and covers the portions of the tooth that need additional support without necessarily covering the entire visible tooth.

A dental crown provides more extensive coverage and is generally considered when the tooth has lost enough healthy structure that broader protection is needed.

When an onlay can adequately restore the tooth, it may allow more healthy natural tooth structure to remain. When the tooth is more extensively weakened or damaged, a crown may be the more appropriate restoration. For more on crowns, read Dental Crowns: When a Tooth Needs More Than a Filling.

Will a Dental Onlay Look Natural?

Tooth-colored onlays can be designed to blend with the surrounding natural tooth while rebuilding the damaged chewing surface.

The appropriate restorative material depends on several factors, including the tooth being treated, the amount of remaining tooth structure and the forces placed on the restoration when you bite and chew.

Dr. Chin can explain the material she recommends for your tooth and why.

What Happens When I Get a Dental Onlay?

Treatment begins with an examination of the tooth to determine the extent of the damage and whether an onlay is an appropriate restorative option.

If treatment proceeds, local anesthetic may be used for comfort while decay, damaged tooth structure or an old restoration is removed as needed. The tooth is then carefully prepared for the onlay.

An impression or digital record may be used to create a restoration designed specifically for the prepared tooth. Depending on how the onlay is made, a temporary restoration may be used while the final restoration is being completed.

When the final onlay is ready, Dr. Chin checks its fit and your bite before it is securely bonded or cemented into place.

Does Getting an Onlay Hurt?

Local anesthetic can be used while the tooth is being prepared to help keep treatment comfortable.

Some temporary sensitivity or tenderness can occur following restorative dental treatment. Your dental team will explain what to expect and when to contact the office if the tooth does not feel right.

How Long Does a Dental Onlay Last?

Dental onlays are designed to be durable, but no dental restoration should be expected to last forever.

How long an onlay lasts can depend on the condition of the underlying tooth, the restorative material, your bite, grinding or clenching habits, oral hygiene and the forces placed on the tooth.

Regular dental examinations allow Dr. Chin to monitor the restoration, the remaining tooth structure and the surrounding gums over time.

Do I Need a Filling, Inlay, Onlay or Crown?

The right restoration depends on how much of the tooth needs to be repaired and where that damage is located.

A smaller area may be restored with a filling. An inlay may be appropriate when more of the chewing surface needs restoration. An onlay extends farther to cover one or more weakened cusps, while a crown provides more extensive coverage when the tooth requires greater protection.

Dr. Chin can evaluate the tooth, show you what she sees and explain why she recommends one restorative option over another.