What Are Crowns?
A dental crown, sometimes referred to as a cap, is permanently bonded to a particular tooth to improve aesthetics and function. A crown can be fitted over the remaining part of almost any prepared tooth and, if properly maintained, can last 15 years or more. When there is insufficient dental enamel to allow restoration with a dental veneer, a crown may be successfully used instead.
Crowns can be used in restorations involving:
- heavily repaired or broken teeth
- discoloured fillings
- a tooth needing protection following root canal therapy.
The shape, size, colour and surface characteristics of a crown are precisely matched to surrounding teeth and provide a seamless and lasting restoration
Types of Crowns
There are three types of dental crown: porcelain, metal, and porcelain-fused-to-metal (PFM) crowns.
Porcelain crowns for back teeth are made of high-strength reinforced ceramic materials (e.g. lithium disilicate or zirconia). For front teeth, porcelain crowns may be made using an aesthetically pleasing ceramic material, or they may involve two layers: a high-strength material covered with an aesthetically pleasing material. All-ceramic crowns for front teeth give a very natural, pleasing appearance; they achieve the closest match to natural, healthy teeth.
Metal crowns, which are often made of gold alloy, require very minimal tooth preparation, as the metal is strong even in thin sections. When designed and constructed well, metal crowns are very durable and resistant to fracture.
PFM crowns appear much more tooth-like than metal crowns due to the overlying porcelain. The metal core provides strength and durability. It is common to have a thin metal margin visible around the neck of the crown on the tongue side of the crown as this preserves more tooth structure.
How Long Do Crowns Last?
Dental crowns can still be subject to fracture and cavities so it is important to look after them just as you would your natural teeth. If properly maintained through good oral hygiene and regular dental check-ups, crowns can last for many years. The material of your dental crown can affect the durability of your crown, but factors other than durability also need to be considered (such as aesthetics, survival rate and kindness to opposing teeth) so you are encouraged to discuss the different options with your dentist to choose the most suitable crown material.
How to Care for Crowns
Crowns perform just like your natural teeth. While they are very durable, you still need to maintain good dental hygiene and to brush and floss the crown just as you do with your other teeth. With regular dental check-ups, proper cleaning and the use of remineralisation toothpastes, you will be able to minimise the risk of decay around your dental crown