What is a crown and when is it needed?
A crown is a “cap” that completely encases your tooth to restore it to its proper shape and to allow it to withstand biting forces. Crowns are strong and can be made to match the colour of natural teeth.
Crowns may needed when:
- A tooth is so badly decayed that a filling cannot be secured to the cavity
- A tooth is broken or fractured (e.g. due to accidents)
- After root canal treatment, if the remaining tooth structure has become too weak.
What are the procedures involved in crowning a tooth?
Based on your dental examination and x-rays, your dentist will remove any decay and may then fill up the cavity. Sometimes, a root canal filling is needed before crowning.
At your first crowning visit, the outer surface of the tooth will be trimmed away conservatively – just enough to create space for the crown. An impression (or a mould) of your teeth will be taken to obtain models of your teeth. These models are sent to a dental laboratory where a customised crown will be fabricated. In the meantime, a temporary crown is placed on the tooth.
At the second visit, the temporary crown will be removed and the definitive crown cemented on the tooth. You will usually need to wait a few days in between these two visits. Some clinics are now able to fabricate the crown within the same day, using CAD-CAM technology. Thus, you will be able to get your crown within one visit.
What material is the crown made of?
- Crowns can be made of many different materials. These can be categorized into three groups:
- Full metal crowns – can be made of gold, precious alloys, semi-precious alloys or base metal. Full metal crowns can be very durable, but are only suitable for back teeth because the colour is so different from natural teeth
- Metal-fused to porcelain (PFM) crowns – these are crowns with an internal layer of metal, overlaid with a porcelain veneer. They offer good durability coupled with good aesthetics.
- Full ceramic crowns – these are the latest materials used for crowns. Only a few years ago, full ceramic crowns were used only for anterior teeth, because the materials gave excellent aesthetics but were somewhat weaker than the metal or PFM crowns. The latest ceramic materials, however, now offer both strength and great aesthetics.
What are the possible complications with crowns?
As with any dental procedures, crowning has its risks – in spite of the highest standards of practice.
Teeth under the crowns are still susceptible to infections, breakage and decay. Good oral hygiene is paramount in preventing decay under the crowns, which can lead to the tooth fracture or loose crown.
Crowns are usually done to reinforce teeth with extensive fillings or teeth that have sustained injury from wear, trauma or crack. As such, there is always a risk that the pulp of these affected/weakened teeth might die and become infected. If this occurs, a root canal treatment may be needed.
What are veneers?
Veneers are thin, tooth-coloured porcelain/ceramics shells carefully crafted to bond and cover the front of teeth. Veneers are done mainly for front teeth.
Veneers are similar to crowns, the difference being that only the front surface of the tooth is trimmed to accommodate a veneer, whereas the whole surface of the tooth is trimmed for a crown.
When are veneers indicated?
Veneers are a more conservative treatment than a crown and can be used as an alternative if the underlying tooth is strong and healthy.
Veneers can be done for the following situations:
- To improve the shape of front teeth that are worn down.
- To change the colour of front teeth that are severely stained and not correctable by whitening
- To improve minor irregularities in the position of the front teeth.
- To improve the shape of malformed teeth.
What is the process like in getting teeth veneered?
Two to three visits to your dentist will usually be required to prepare the teeth and fit the veneers. To prepare each tooth, a thin layer, about the thickness of your fingernail, will be shaved off – to allow rooms for veneers.
An impression of the prepared teeth is taken and sent to the a dental laboratory to fabricate the veneers. While waiting on your customised veneers, the teeth might feel rough and strange due to the exposed, buff surfaces during this interim period. Once the final veneers are glued on, the surface of teeth will feel smooth again.
How do I care for my veneers?
- Regular checks with the dentist who fitted them is recommended.
- Excessive chewing or biting, especially on hard food is to be avoided. If veneers are struck by hard objects, porcelain veneers can fracture, just like normal tooth
- Good dental hygiene is crucial for longevity of these veneers. Conscientious daily brushing with fluoride toothpaste and flossing will help to prevent decay.