A useful guide to Crowns from Evesham Place Dental!

What is a Crown?

A crown is a type of dental restoration which completely caps or encircles a tooth or dental implant.

When a large cavity has weakened a tooth it is often the best solution.

Crowns can also be used to improve the appearance of teeth and sometimes to realign them.

Older crowns will need replacement when they cease to match adjacent teeth or have broken down.

Materials

Many different types of materials can now be used to make a crown:

Traditionally, the best quality restoration was made of a high gold content (60%+) alloys.

This is very durable and the margins can be burnished onto the tooth to ensure a very good fit.

Not everyone likes the appearance of gold in their mouth and they are obviously quite expensive!

Other non-precious metals can be used for crowns, particularly thin onlays (which only cover the biting surface).

Crowns can be adhesively bonded to protect teeth with minimal tooth reduction.

Porcelain or ceramic crowns have evolved tremendously over the last few years.

Original porcelain crowns were prone to fracture and hence they were reinforced with metal so called VMK or bonded.

Observations

To get a natural appearance is difficult without drilling a lot of tooth away and if gums recede an unsightly grey line can be seen at the join.

In the modern era of ‘Adhesive Dentistry’ the tooth coloured crown now predominates with big advances in strength and appearance.

Zirconia is a tooth coloured metal which is extremely strong, however as it is slightly more opaque that some other materials.

It is perhaps not the best material to match individual front teeth but it is an excellent choice for bridgework (joined crowns made to replace missing teeth).

The best ceramics, (brands such as IPS Empress and E-Max by Ivoclar Vivadent AG) can match natural teeth so well that any join between the crown and tooth is almost imperceptible.

They are also ideal for hybrid type preparations like veneers (non- circumferential) and overlays which allow less sound tooth structure to be taken away.

Also on the market are hybrid crowns of ceramic materials in a resin matrix (resin-nano ceramics). The most recent versions of these such as ‘Enamic’ by Vita claim to match the best ceramics with the added advantage of being easier to repair.


Notes

An interesting article by a acknowledge expert on the clinical application of dental materials can be found at ;

http://www.dentaleconomics.com/articles/print/volume-103/issue-6/practice/which-indirect-restorations-do-dentists-want-in-their-own-mouths.html

With our experience of multiple techniques and materials at Evesham Place Dental Practice.

Our team can assess your suitability for a full range of crowns at competitive prices, including; those made by CEREC CAD/CAM technology in single visit of less than two hours.