Crowns & Onlays

Onlay.jpg

Onlay preparation and fitting on an upper right 4 tooth.

Crown material used: Zirconia

Crowns and Onlays are examples of indirect restorations (made "indirectly", by a dental laboratory at an external site).

These types of restorations are options for teeth which:

  • Have lost significant amounts of tooth structure due to tooth decay or trauma.

  • Have undergone root canal treatment and are therefore more brittle and at a greater risk of fracture.

  • Have very large fillings in them which are regularly failing or have fracture-lines stemming from them, extending into the natural tooth tissue.

There are also other situations in which your dentist may advise you to consider a crown or onlay.

The process for crowns is split into two appointments:

1. Preparation:

  • The dentist takes impressions, records the bite and shaves down the tooth to make space for the crown.

  • The amount of tooth shaved off depends on the tooth, whether there is any decay/fracture lines in the tooth, and the material of crown to be placed on the tooth.

  • We check you're happy with the tooth shade (for non-metal crowns only).

  • The dentist will then send the impressions/bite record to the laboratory who will create a custom made crown/onlay for your tooth.

  • You will be given a temporary crown to help protect the tooth while you're waiting for your crown to be fitted.

  • It usually takes 10-14 days for the lab to return the indirect restoration back to us for fitting.

Before commencing the crown preparation, your dentist will discuss different material options with you.

Different materials have different pros and cons, including:

  • Strength

  • Aesthetics

  • Toughness

  • Wear resistance

  • Requirement to remove more/less tooth structure during preparation

  • Cost

2. Fitting:

  • The crown/onlay is ready to be fitted.​

  • The dentist will use a strong cement to place the crown on the tooth, remove any excess cement and then hold down the unit until the cement has fully set.

  • Once the cement has set, the dentist will check you're happy with how it feels in the mouth, help you navigate your bite, and give you post-operative instructions.

Crowns and onlays typically feel strange on initial fitting. Naturally, teeth adapt to changes and over time the teeth generally conform to the changes made by moving slightly.

Discomfort can generally be improved by slight adjustment of the crown/onlay after fitting by the dentist.

There is a small risk of death of the tooth during a crown/onlay preparation procedure due to heat generated in the shaving procedure.