In many instances there is simply insufficient tooth substance to allow the direct placement of fillings. Crowning of such a tooth maybe the only viable option to allow to ensure long term function. Crowns can hold together portions of a fractured tooth, support dental bridges to fill gaps created by missing teeth and provide longevity to heavily restored teeth. Some people refer to dental crowns as caps. Dental crowns are similar in shape to dental veneers except that crowns cover all the surfaces of a tooth whereas veneers only cover the visible outside surface of the tooth.
What is a crown?
A crown is custom made precision item that is cemented over your tooth or implant to completely cover it. Traditionally crowns have been described as metal or ceramic fused to metal. However, advancing technology has provided materials based on Zirconium. These materials are very strong and durable thus eliminating the requirement for a metal substructure for your crown. Ceramic crowns now are the gold standard in providing the ultimate aesthetic result.
Why are they used?
Crowns are prescribed as a part of a treatment to restore teeth that have:
- Undergone root canal treatment
- Severe tooth surface loss
- Been heavily restored
- Poor aesthetic appearance
- Replace existing crowns with poor appearance
- To protect heavily restored teeth from breaking
- To restore broken down teeth and prevent further breakage
Initial consultation, assessment and planning will occur with one of our dentists. All options appropriate to your case will be thoroughly discussed. Preoperative pictures, radiographs and tooth shade may be taken. In certain cases, particularly cosmetic cases, impressions are taken to allow our ceramist to provide a diagnostic wax up that will physically allow you to visualise and approve the intended outcome.
A sufficient amount of tooth substance and appropriate"core" must be in place prior to provision of a crown.
At your second visit the tooth to be crowned is prepared carefully and precisely. An impression will be taken of the tooth and sent to our ceramist along with your custom prescription. A temporary crown will be constructed to provide you with an aesthetic, functional and protective provisional restoration. In the meanwhile our ceramist will follow your custom prescription to hand craft your crown.
The preparation procedure usually is a single visit of 60minutes. However, this may be longer or involve multiple visits depending on the extent, complexity and number of crowns.
At your final visit the provisional crown is carefully removed and your custom made crown tried in. You will be shown the crown at this try in stage. Once you confirm that you are pleased with the appearance and fit, your dentist will cement the crown to your tooth.
It is generally accepted that between 1 in 5 and 1 in 8 teeth that have been crowned or have deep fillings in them go on to become non-vital and require a root canal treatment at some stage and this can be many many years after the initial crown.
Recall and Review
It may take a couple of days for you to become accustomed toyour new crown. It is important to employ a strict oral hygiene regime encompassing professional hygiene intervention, as a crowned tooth is not protected from decay or gum disease. You will be shown the most appropriate method to ensure optimal oral health. As with any treatment, regular recall and review is essential to ensure optimal status of your crown.
Types of Crown
Various types of crowns are offered, their cost depends on the material of choice, time taken, complexity of work and laboratory used.
Emax is our preferred indirect restoration. White and incredibly aesthetic, often indistinguishable from natural teeth which can be bonded to the tooth.
IvoclarVivadent’s patented lithium disilicate material is truly a revolution for the dental industry. Never before has a material been able to combine high strength, high aesthetics and ease of use into one product, until now. The opalescence, translucency and light diffusion properties of IPS e.max lithium disilicate were all designed to replicate natural tooth structure for beauty and undetectable restorations.
Zirconia is the strongest crown material on the market today allowing the Dentist to use it on the back teeth even in people who grind or clench their teeth with minimal risk of fracture.
Porcelain Bonded to Metal
White porcelain bonded to a metal sub-structure. The metal gives strength whilst the porcelain gives the white colour. Not as natural looking as emax crowns. The metal substructure may be non – precious or precious metal depending on the patient’s choice. Precious metal is generally preferable as it is more biocompatible with the gingivae (gums) leading to less inflammation and less prone to corrosion. The weak point here is the bond between the porcelain and metal, and over time the porcelain may break away from the metal. Also, as gums recede with age, a black line may be seen above the crown and this leads to an unsightly smile. This blackness is the metal in the crown. This does not occur with all porcelain/ceramic crowns.
Metal crown. Very strong and durable. Has been a successful restoration for many decades. Has the most similar wear characteristics to natural tooth enamel and therefore is very effective on back teeth, especially in people who grind their teeth. The nature of gold as a material also allows minimal tooth preparation thus preserving more tooth structure.
Inlays and Onlays
Decay or other damage to the upper portion of the tooth may be treated with an inlay or onlay. A dentist at our practice can evaluate the condition of your tooth and determine the best treatment option. Inlays and onlays are dental prosthetics that are designed to cap only the upper-most portion of the tooth. Like dental crowns, they are fabricated from porcelain for durability, strength, and cosmetics. Inlays and onlays are used to treat back teeth which have lost one or more cusps and are secured in place with dental cement. We can offer same appointment inlays/onlays by using our sophisticated CAD/CAM CEREC machines without the need for impressions. A virtual impression is taken with a special camera from which we design and mill the inlay/onlay immediately in- house. Ask for Dr Colum Boyce as he our specialist Cerec provider.