Inlays & Onlays

When more than half of the tooth’s biting surface is damaged, a dentist will often use an inlay or onlay.

What are inlays and onlays?

Inlays and onlays can be made of porcelain, gold, or composite resin. These pieces are bonded to the damaged area of the tooth. An inlay, which is similar to a filling, is used inside the cusp tips of the tooth. An onlay is a more substantial reconstruction, similar to the inlay but extending out over one or more of the cusps of the tooth.

Traditionally, gold has been the material of choice for inlays and onlays. In recent years, however, porcelain has become increasingly popular due to its strength and color, which can potentially match the natural color of your teeth.

How are inlays and onlays applied?

Inlays and onlays require two appointments to complete the procedure. During the first visit, the filling being replaced or the damaged or decaying area of the tooth is removed, and the tooth is prepared for the inlay or onlay. To ensure proper fit and bite, an impression of the tooth is made by the dentist, and sent to a lab for fabrication. The dentist will then apply a temporary sealant on the tooth and schedule the next appointment.

At the second appointment, the temporary sealant is removed. Drs. Wong or Cheng will then make sure that the inlay or onlay fits correctly. If the fit is satisfactory, the inlay or onlay will be bonded to the tooth with a strong resin and polished to a smooth finish.

Considerations for inlays and onlays

Traditional fillings can reduce the strength of a natural tooth by up to 50 percent. As an alternative, inlays and onlays, which are bonded directly onto the tooth using special high-strength resins, creating a tight, superior fit to the natural tooth. This increases the strength of a tooth by up to 75 percent. Such restorations can be used in instances where much of the tooth structure has been lost. As a result, the tooth remains intact and stronger. In some cases, where the damage to the tooth is not extensive enough to merit an entire crown, onlays can provide a very good alternative.

Replacing old filling with an inlay or onlay

You can have your old fillings replaced with inlay or onlay. This process requires two appointments.

Your First Appointment:

  1. The old filling is removed along with any additional decay.
  2. An impression is made of your teeth. A model of your teeth is made and sent to the lab.
  3. A temporary onlay is placed on the tooth.

At the Lab: A resin is carefully placed into the model of your teeth. It is then designed to look natural.

Your Second Appointment:

  1. The temporary onlay is removed.
  2. A conditioning gel is placed on your tooth to prepare it for the new onlay.
  3. Bonding cement is placed on the tooth and a high intensity light bonds the resin to the tooth.
  4. The tooth is then polished.

Your teeth are restored to a natural look and feel, they are stronger and the tooth is protected!