Dental Inlays and Onlays 101: Everything You Need to Know

Dental Inlays and Onlays 101: Everything You Need to Know

Jun 01, 2020

When you have decay that is too extensive for a simple filling, but not severe to warrant a full-coverage crown, dental inlays and onlays are the ideal treatment. Our Brookfield dentist may recommend inlays/onlays dental treatment to correct your worn out teeth and here is what you need to know.

What are Inlays and Onlays?

Ceramic inlays and onlays are the most common form of restoration. These indirect fillings that are made at the dental laboratory and bonded to the teeth using cement.

  • Dental inlays

Dental inlays are fitted on the pits of the teeth but do not cover the cusps. The inlays are ideal if you get an injury or decay that does not extend to the rest of the chewing surface.

Inlays differ from direct filling in various ways. While inlays are polished to minimize recurrent decay, direct filling shrink during fixing, which increases your chances of failure. Also, inlays have a longer shelf life and come in different materials.

  • Dental Onlays

Dental onlays are used if the decay or damage extends to the cusps. Traditional onlays come in different materials but composite inlays and onlays are ideal because they resemble your real teeth.

When Are Inlays and Onlays are Used?

The dentist may recommend in inlays or onlays if:

  • The teeth are broken, decayed, or fractured but the damage does not affect the cusps of the tooth
  • The injury does not allow the removal of tooth material enough to support a crown.
  • The damage is extensive but the large dental filling needed may weaken the remaining tooth structure.

How Are Dental Inlays and Onlays Fixed?

The process of fixing inlays and onlays is the same. The treatment aims to preserve the teeth, and therefore the enamel is not reshaped like in dental crowns. Crowns require the teeth reshaping to make room for the restorations. To get the inlays and onlays, you will need at least two dental visits.

  • First dental visit

During your initial consultation, the dentist will examine and assess the teeth and the extent of the decay. Next, the teeth are cleaned and decay removed. A small amount of the tooth surface is removed depending on the size of the material needed.

The dentist will take an impression of the tooth to send to the lab to create the final inlays and onlays. A temporary filling is fixed to protect the teeth as you wait for the permanent ones.

  • Second visit

On your second consultation, the temporary fillings are replaced with permanent ones. A resin or cement is used to fix the restorations.

When fixed correctly, the inlays and onlays give a seamless look.

Pros and Cons of Inlays


  • The restorations are strong and durable and can last for years with proper dental care.
  • They restore the appearance of the teeth. The ceramic inlays and onlays offer an excellent shade that matched your natural teeth.
  • The restorations have less post-operative sensitivity


  • These restorations are expensive
  • The fixing process is lengthy
  • A few complications may arise such as staining
  • Ceramic and composite have low strength than the gold inlays
  • The inlays and onlays are durable but may need replacement after some time.

Can Inlays and Onlays Fail?

Inlays and onlays are durable and effective, however, they can fail and a few factors can increase the risk:

  • Poor dental hygiene. Plaques and cavities affect the lifespan of the restoration. It is, therefore, important to have oral hygiene before and after getting the dental filling. Remember, inlays and onlays do not reduce the risk of decay.
  • Grinding and clenching. Bruxism cause restorations to wear down. It essential to wear a mouthguard when sleeping.
  • Age. Indirect fillings are not ideal for children under 16 years because the pulp chamber is large. Having the fillings risks nerve damage which is vital for teeth nourishments. It is recommended to choose other dental procedures or wait until the teeth have fully developed.

Schedule an Appointment

Visit The Dental Team by booking an appointment with our dentist near you, and know more about dental inlays and onlays and assessment if you are a candidate for the restorations.