About Dental Crowns

What do you mean by dental crowns?

Crowns are an ideal way to rebuild teeth which have been broken, or have been weakened by decay or a very large filling. The crown fits right over the remaining part of the tooth, making it strong and giving it the shape and contour of a natural tooth. Crowns are sometimes also known as ‘caps’. An ‘Anterior Crown’ is a crown fitted to the front eight teeth. Crown is cemented over the gum line and it covers the whole teeth making it completely invisible.

Why would we require dental crowns?

Dental crowns will be needed for a number of reasons like :

• the tooth may have been weakened by having a very large filling
• you may have discoloured fillings and would like to improve the appearance of the tooth
• you may have had a root filling which will need a crown to protect it
• you may have had an accident and damaged the tooth
• it may help hold a bridge or denture firmly in place.
• To hold the parts of cracked /chipped tooth
• To keep the dental bridges in place
• To cover discolored/ badly shaped teeth
• Crown covers a dental implant

What type of crowns is available?

Crowns are available of a variety of materials and new materials are being introduced all the time. Here are some of the options available at present:

• Porcelain bonded to precious metal: this is what most crowns are made from. A precious metal base is made and layers of porcelain are then applied over it. These crowns can match the color of the teeth. As compared to metal crowns, more wearing of teeth is required. The porcelain may break /crack. But such crowns look like natural teeth. Sometimes the metal placed under the crown is visible at the gum line, hence these crowns are suitable for back/ front teeth.
• Porcelain: these crowns are not as strong as bonded crowns but they can look very natural and are best for the front teeth and suitable for people who are allergic to metal. Though not so strong but matches the color of the natural teeth.
• Precious metal (gold and palladium): these crowns are very strong and hard-wearing, but are not usually used at the front of the mouth, where they are highly visible. In case of metal crowns less teeth is reduced, and reduction of adjacent teeth is minimum. Such crowns are very strong and do withstand chewing and biting pressure. Metal crowns do not crack or break. Alloy of gold, palladium, nickel are used in case of metal crowns .The only drawback of metal crowns is the color .These crowns are best suited for out of sight teeth / molars.

How is a tooth prepared for a crown?

The dentist will prepare the tooth to the ideal shape for the crown. This will mean removing most of the outer surface, and leaving a strong inner ‘core’. The amount of the tooth removed will be the same as the thickness of the crown to be fitted. Once the tooth is shaped, the dentist will take an impression of the prepared tooth, one of the opposite jaw and possibly another to mark the way you bite together. The impressions will be given to the technician, along with any other information they need to make the crown.

Does it hurt to have a tooth prepared for a crown?

No. A local anaesthetic is used and the preparation should feel no different from a filling. If the tooth does not have a nerve, and a post crown is being prepared, then local anaesthetic may not be needed.

Will the crown be noticeable?

No. The porcelain crown will be made to match your other teeth exactly. The shade of the neighbouring teeth will be recorded, to make sure that the colour looks natural and matches the surrounding teeth. A temporary crown, usually made in plastic, will be fitted at the end of the first appointment to last until the permanent one is ready. These temporary crowns may be more noticeable, but they are only in place for about two weeks.

How long does the crown last?

The life of a crown will depend on how well it is looked after. The crown itself cannot decay, but decay can start where the edge of the crown joins the tooth. It is very important to keep this area as clean as your other teeth, or decay could endanger the crown. Properly cared for crowns will last for many years – Dental crowns have a life of say 5 -15 years .One has to take extra care of the crown .Biting nails, opening packets, chewing hard things etc. are a few habits which have to be corrected .Moreover brushing teeth twice a day is a must and floss at least one time in a day.

How are crowns fixed to teeth?

Once the fit and appearance of the crown has been checked – and approved by you – it will be cemented in place with special dental cement. The cement also forms a seal to help hold it firmly in place.

Will the crown feel different?

Because the shape of the crown will be slightly different from the shape of your tooth before it was crowned, you may be aware of it to begin with. Within a few days it should feel fine, and you will not notice it. The crown may need some adjustment if it feels higher than the surrounding teeth. If it is at all uncomfortable ask your dentist to check and adjust it.

What problems can one face with crowns?

• Teeth may be sensitive to hot/cold after the effect of anesthesia is over.
• There can be irregular bites which results in pain.Such problem occur when the crown is placed too low / high.
• Sometimes the cement under the crown gets washed away and the crown becomes loose.

Hence proper care should be taken and regular dental checkups are required to maintain a healthy dental structure.