Inlays and onlays, also termed indirect fillings, provide dental restorations for teeth. They are preferred treatment for slight to moderate tooth decay and are a more conservative choice than full coverage dental crowns. They offer a well-fitting, stable, and durable solution to tooth decay or similar damage.

An “inlay” involves the bonding of material within the center of a tooth. An “onlay” treats the surface or edge of the tooth, including one or more points of the tooth. Inlays and onlays are made from porcelain or composite materials and offer a “filling” for teeth that are damaged by tooth decay or similar problems. They are made in a dental laboratory, rather than molded into place in the mouth, as with regular dental fillings. Inlays and onlays are adhesively fixed into place by your dentist, and are long-lasting and natural-looking.

Benefits of Inlays and Onlays

The benefits of inlays and onlays include fit and esthetics. They are designed to preserve as much of the healthy tooth as possible and strengthen a damaged tooth. As opposed to a direct composite filling, inlays between the teeth seal out bacteria better.

The following are further benefits of inlays and onlays:

  • Superior and precise fit
  • Tooth is easy to clean
  • Preservation of natural tooth structure
  • Strength and stability
  • Maintenance of tooth color
  • Protection of weak tooth

Selecting a Dentist for an Inlay or Onlay

There are relatively few dentists who are adept at performing this type of inlay and onlay procedure. This is due to the fact that dental schools do not offer formal training for porcelain inlays and onlays. The dentists who are familiar with the inlay/onlay procedure may have received training while working intently with their dental laboratory technicians. Some dentists consult with dental technicians while planning treatment options for the restoration of your tooth.

The Procedure

In most cases, an inlay or onlay procedure is accomplished in two visits to the dentist. During the first visit, your dentist takes a molded impression of the damaged tooth. The impression is then sent to a dental laboratory, where an inlay or onlay is created. While waiting for the final restoration, a provisional inlay or onlay may be fitted on your tooth to protect it.

During the second visit, the provisional inlay or onlay is removed and your final restoration is put in place. Your dentist will examine all margins to ensure a smooth and tight fit. Your dentist will also inspect your occlusion to determine that there are no complications with the bite disturbing the margins of the restoration. The inlay or onlay is then bonded onto your tooth and the margins are polished.

Materials Used for Inlays and Onlays

The materials used for your inlay or onlay may be gold, resin, or porcelain. Gold is the material of choice if esthetics is not a concern (for example, with back molars). Resin may be the most reliable alternative for individuals who grind their teeth and/or those with malocclusion. Inlays and onlays made from porcelain present the best esthetics and are frequently used in areas of the front teeth.
Inlays and onlays continue to improve as the materials used to manufacture inlays and onlays take on more esthetic and functional qualities in their structure and fit. Because they rate very high on durability and stability, inlays and onlays are not likely to be replaced by another restorative treatment any time soon.

Cost of Inlays and Onlays

The cost of a dental inlay or onlay procedure depends on several factors, including your location, the type of material used, and the size of the inlay or onlay. Furthermore, back teeth are more difficult to work on than front teeth, resulting in higher costs. The dentist’s fees may also vary according to his or her experience and training in carrying out the procedure.