Inlays & Onlays
Porcelain inlays and onlays are a type of ceramic dental prosthesis used for restoring small-to-moderate areas of tooth decay. They are designed to provide:
- A natural-looking appearance that matches surrounding teeth
- Customized fit based on the latest technology for fabrication of dental restorations
- A conservative approach compared to crowns (little healthy tooth tissue is removed)
- Superior performance compared to resin composite materials (ceramics last longer and do not stain or change color)
- Added strength and prevention of further damage over time (Placement of large metal amalgam fillings requires making a large hole which can weaken the tooth. Also, metal expands and contracts with changes in temperature which can further stress the tooth.)
- A high level of biocompatibility (The body does not have an allergic or chemically sensitive reaction to ceramic inlays and onlays.)
Who is a Candidate for Porcelain Inlays and Onlays?
Patients with decay or damage to the chewing surfaces of their premolars or molars can usually be successfully treated with porcelain inlays and onlays. An inlay is used when the cavity is affecting the center of the tooth’s chewing surface. An onlay is recommended when the cusps (the edges) of the tooth also need to be restored. The treated area may extend down along the sides of the tooth as well. This treatment works best for patients who are committed to preventing further tooth decay by practicing good oral hygiene and having regular prophylactic cleanings.
When are Porcelain Inlays and Onlays Not Suitable?
Ceramic inlays and onlays are not always the best restoration option for every tooth. Here are some situations in which your dentist or prosthodontist may recommend a different approach:
- Using ceramic material on a biting surface might cause undue wear on opposing teeth. In this case, a metal amalgam or gold filling might be suggested as an alternative. These metals have a little more “give” and are not as hard or as brittle as porcelain. The exact contours and location of the molar being restored will play a role in determining whether ceramic is the right option.
- The area being restored is very small. Porcelain inlays and onlays are some of the more expensive options for tooth repair. Patients who have only minor tooth flaws may wish to choose a less costly filling material such as tooth colored resin or metal amalgam if pricing is a major concern.
- There is a chip or shallow fracture on a front tooth. A porcelain veneer is a more suitable treatment for minor damage if the tooth is otherwise structurally sound. Small cavities in front teeth are treated with dental composite if the patient wants a tooth-colored filling.
- The damage is too extensive and there is not enough healthy tooth tissue remaining. In this case, a crown may be a better choice since it restores all surfaces of the tooth. Ironically, a full ceramic crown can sometimes be cheaper than a partial restoration with a ceramic onlay.
- The tooth has an abscess. After a root canal, the remaining tooth structure may be weakened to the point where a full crown is needed for adequate restoration.
Treatment Overview for Porcelain Inlays and Onlays
The procedure begins with an oral exam and x-rays to determine the extent of decay or damage present. The dentist will then select a color shade to match the enamel on your teeth. Next, the dentist places a rubber dam in your mouth to isolate the tooth. If the decay extends down onto the side of the tooth, small wedges are placed between the molars to separate them just enough to get a clear impression of the whole area. The treatment area is numbed and the decayed portion of the tooth is drilled out to prepare a space for the inlay or onlay. The dentist makes a mold of the prepared tooth and sends it to a dental fabrication laboratory. A temporary filling is placed to protect the tooth until the ceramic inlay or onlay is completed (this usually takes two to four weeks).
During the second visit, your temporary filling is removed, and the porcelain restoration is bonded in place using a strong dental adhesive. A rubber dam is used during this step as well to make sure no moisture comes in contact with the bonding material (contamination with saliva can cause the inlay or onlay to come out later). Your dentist will shape and polish the exterior surface of the ceramic inlay or onlay. The contact between the restoration and the opposing tooth will be checked at this point to ensure proper function. After this, your tooth restoration is complete. You can care for the molar like any other tooth with daily brushing and flossing.