A set of broken teeth that can be restore with a dental onlay or dental crown.

Dental Onlay or Dental Crown?

Dentistry should be focused on the preservation of one’s tooth structure. During treatment, we want to remove diseased tooth structure that has decay, unsupported enamel with fractures, or any defective restorations. The rest of the tooth should be preserved as much as possible, and not replaced with foreign material. However, when the tooth cannot be fixed, you will have two options: a dental onlay or a dental crown.

The Difference Between a Dental Onlay and a Dental Crown

In traditional dentistry, your dentist needs to remove some healthy tooth structure to allow for the thickness of the new, restorative material (filling or the crown) or to allow for the new restoration (crown) to be retained on the tooth so it doesn’t fall out. However, that leads to over-cutting the tooth and damaging results.

When one cusp of the tooth is damaged and needs to be restored, you will have two options: a dental onlay or a dental crown.

A dental onlay and a dental crown are both indirect restorations. An onlay is usually fabricated from either porcelain or gold, and is cemented or bonded onto a tooth. Bonding is a better option, but the procedure is more difficult for dentist to do. An onlay replaces only damaged or compromised cusps, but keeps the majority of tooth intact.

A dental crown is usually fabricated from gold, metal with porcelain covering, or porcelain only. A crown requires that a great deal of the tooth structure be removed to allow the crown to fit around the tooth. Margins of the crown are usually placed under the gums for aesthetic reasons.

The Better Option?

A dental onlay bonded to a tooth.

A dental onlay provides a better option for preserving tooth structure.

In both cases, broken cusps of the tooth are replaced. On the other hand, an onlay is a far less invasive option, preserving a majority of the tooth. In any dental treatment, it is important to know that dental restoration doesn’t last forever, and it eventually breaks down for various reasons. The force of chewing, the breakdown of the cement used for cementation, imperfection of the restoration margins, and penetration of bacteria, are just a few of the causes of dental restoration breaking down.

At that time, a new restoration should be fabricated. This requires your dentist to remove more tooth structure in order to restore the tooth. Since the earlier, more- aggressive treatment, the tooth strength becomes compromised. There may be insufficient remaining tooth structure to restore the tooth successfully. When that happens, the tooth is considered non-restorable and needs to be extracted.

With a dental onlay, more tooth is preserved. The likelihood of new decay is lower and onlay can be redone, or if necessary, a dental crown can be fabricated. Therefore, onlays help patients to preserve their teeth long-term, and prevent tooth loss and more invasive treatments later.

It is important to take note, although a dental onlay is a better treatment for you, dental insurance companies may not consider an onlay as a covered benefit. This is why many dentists may choose the crown, which is covered by most insurances.  Speak with your dentist about what is best for you, and how you can preserve your teeth.


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