An onlay is a “fixed partial cap” made of reinforced porcelain or gold which provides solid protection of the cusps(peaks) of the tooth. It provides partial coverage of a tooth like a “flat cap” It can be used to restore the strength, shape and improve the appearance of a tooth.
When is an onlay indicated?

Onlays are sometimes indicated in these following circumstances;

  • when your tooth has moderate to large cracks and/or fractures
  • extensive cavity with little remaining healthy tooth structure
  • teeth which have received root canal treatment
  • teeth which have too little healthy structure left for a conventional white filling

Advantages of onlays over large fillings

An onlay is considered more of a long term restorative option for a broken down tooth rather than a conventional white filling. This is because conventional fillings may need repair and replacement over time due to wear and tear. This is especially so on back teeth (molars) and in cases where someone has lost some teeth so the molars are working harder to chew.

Similar to dental crowns, onlays are ideal to strengthen and support the remaining tooth structure. They are the superior option over direct dental fillings to protect weak teeth and prevent cracked teeth from breaking further. They have more predictable long term strength and they preserve more tooth structure to avoid the need for repeated repair and maintenance.