Dr JP Steyn is a prosthodontist specializing in the cosmetic restoration and replacement of teeth.
What are Crowns?
Dental crowns (caps) are laboratory produced restorations that envelope the entire tooth. They are cemented, or bonded to the tooth for a natural appearance. Typically these are used to improve the appearance of fractured or decayed teeth.
Crowns can be made of gold and other metals, resin and porcelain fused to metal, and all ceramic, or zirconia. They can be made with digital cad/cam technology or handcrafted, or a combination both.
Crowns require more of the structure of the tooth to be removed in order to allow adequate space for the restorative material. This is necessary for it to have enough strength and be able to improve the appearance of the tooth, as well as allowing a healthy gum contour. Because a crown covers the whole tooth, they often provide better solutions for more severe dental problems.
The patient before treatment.
A full make-over with porcelain crowns and crown-lengthening.
Fitting dental crowns usually require up to three visits to the surgery. During the first visit the tooth will be prepared by having decay removed and shaped. A temporary crown will be fitted.
The temporary crown will be removed on the next visit, and a “try-in” of the crown will be done. The final crown will be fitted and adjusted. It will then be cemented or bonded into place at the final visit.
What are the benefits of dental crowns?
Many people have unexplained pain from filled back teeth, which is usually due to hairline cracks in the chewing part of the tooth. Placing crowns on these teeth relieves the pain and allows a return of full dental function for these teeth. In front teeth, older fillings can both weaken the teeth and cause aesthetical issues due to staining or chipping. In teeth with root canal fillings, crowns can prevent breakage.
What are the differences between Zirconia and Porcelain crowns?
The characteristics of each material make them ideal for different situations, which has to be assessed according to each individual’s needs.
The patient before treatment.
A make-over with zirconia crowns and an implant bridge: implants were placed in that area to restore the missing teeth.
How long will a crown last?
The average crown has a lifespan of around 10 – 15 years. This is affected by oral hygiene habits.
What are bridges?
A bridge is used to replace lost teeth by attaching a false tooth the tooth next to it. This however means that the adjoining tooth has to be prepared in the same way as a tooth that is going to be crowned – if this tooth needs a crown or restoration, this is not problematic, but may be undesirable to do to a healthy tooth.
Bridges are seldom used today as dental implants have almost completely replaced them.
Crowns or veneers?
Both dental crowns and veneers can be used cosmetically to improve the appearance of teeth by improving the shape or colour. This is done by bonding thin pieces of porcelain to the surface of the tooth. Veneers can be used over healthy teeth to improve your smile. Crowns, on the other hand are used to improve the appearance of damaged/stained teeth, where there is less tooth structure available, or when there has been a root canal, and the structure of the tooth is brittle. The tooth is recontoured, so a crown can fit over the top.
The major difference between crowns and veneers is the amount of tooth structure that needs to be removed. A good reason why veneers are so popular is that very little enamel is removed compared to crowns, which require eliminating a large portion of the tooth.
Variables affecting the decision whether to use crowns or veneers include: