Our latest blog in the Treatment Focus series looks at crowns: what they are, what they’re made of, when are they needed, and how long do they last?
What is a crown?
A crown is essentially a cap which covers the tooth and is moulded to its shape so that it restores the tooths natural shape, size and strength. They fully cover the visible part of the tooth above the gumline, to improve the appearance and protect a badly damaged tooth underneath.
What are crowns made from?
Crown’s can be made from a variety of materials;
- Stainless steel – these are usually temporary crowns used whilst a permanent crown is being molded to fit a tooth
- Metals such as alloys containing either a high content of gold or platinum, or a high content of base-metal alloys, are often used as these can withstand biting and chewing forces and are the highly durable. However, the colour can be unsightly on front teeth – they are most often used for molars which are not easily visible
- Porcelain-fused-to-metal – these can be matched to the colour of natural teeth, but are not as durable as metal crowns and can cause wear on the surrounding teeth. They are good for visible teeth and for bridges (as the metal helps keep the bridge strong) but another downside is that the metal can become visible in places, for example at the gumline if the gums recede.
- Resin – whilst these are cheaper than other types of filling, they don’t last as long; they are more prone to chipping and fractures and will wear down over time
- All-ceramic or all-porcelain – these are best for matching natural tooth colour, and can be used for people with metal allergies
When is a crown needed?
There are many uses for crowns but broadly speaking they are used when a filling on its own is insufficient to repair damage. They can cover and support a large filling when there is not much natural tooth remaining, and they also can be used to protect weak teeth or prevent them from cracking. If the tooth is already cracked, then a crown can be used to hold the pieces together and prevent further damage. They can also be used alongside other treatment such as holding a dental bridge in place (a false tooth which fills a gap left by a missing tooth), covering an implant or covering misshapen or severely discoloured teeth. The can even be used to make cosmetic changes to teeth, not just as part of damage repair.
How long do crowns last?
Crowns are designed to be durable and therefore you would expect them to last at least 10 years, but it’s not uncommon for them to last much, much longer. Of course, it depends on the position of the crown in the mouth as to how much ‘use’ it gets, and what it’s made from also plays a part in its longevity. However, if you’re concerned about the expense of a crown remember that they get used every meal time, and still last a decade and often much longer!
For more information or to book your next dental appointment, please get in touch.