The Difference Between Inlays, Onlays, and Dental Fillings

The Difference Between Inlays, Onlays, and Dental Fillings

Sep 20, 2018

When a tooth becomes affected by tooth decay, you probably think that a dental filling is the only solution to repairing it. While that is the most common dental solution for cavities, it is not the only form of dental restoration. Two other options for repairing damaged teeth are inlays and onlays.


Inlays are usually recommended when a patient has decay located on the back teeth’s chewing surfaces (around the center of the tooth). They are the preferred choice when the area of decay is fairly large; using conventional fillings in those cases will not be enough to cover and treat the whole area. Because it cannot provide the strength and structure that the tooth needs to last, if a regular dental filling is used to cover too large an area, there will be a risk of fracture.

Inlays can be made from several different materials, including gold and porcelain. They are a good solution for holding the rest of the tooth together and restore normal chewing and biting function.


Like inlays, onlays can also be used to repair the chewing surface of the back teeth, but they are more commonly recommended when the cusp of the tooth is damaged. This is the raised point of the outer edges of the tooth. These can also be made of porcelain or gold and are used to treat larger areas of decay.

How are inlays and onlays made?

Inlays and onlays are both called indirect fillings because, instead of being applied directly onto a tooth or teeth, they are created by a dental laboratory from impressions taken of the prepared tooth. This means that they are custom-made for each patient so that the restoration fits perfectly with the surrounding teeth and existing bite. Some dental offices are equipped to create porcelain restorations in-house, eliminating the need for a second visit as well as the wait time for the inlay or onlay to be created.

How are inlays and onlays different from dental fillings?

As previously mentioned, inlays and onlays are called indirect fillings because they are not applied directly onto the teeth. Dental fillings, on the other hand, are placed onto the teeth right after the decay has been removed and the tooth has been cleaned. In the past, silver fillings were popular, but today, composite resin fillings are more commonly used, as they can be matched to the color of the natural teeth.

Dental fillings may be the most convenient solution to tooth decay, but if you should be affected by it, be sure to discuss these options with your dentist. Together, you can determine which is the best technique for restoring your teeth.

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