Why Do I Need a Crown or Bridge?

 Crowns are required when there is insufficient tooth structure remaining to support a conventional filling. This is usually dictated by one or more missing cusps of molar teeth and large fractures or lost fillings of anterior teeth. Crowns usually cover the entire visible surface of the tooth. Crowns can also be placed to protect cracked teeth.

There are also onlays which cover just the biting surface of the tooth. Their benefit is that less tooth is removed.

Bridges are used to replace missing teeth and can involve either one or both of the teeth adjacent to the gap.

There are various materials available for crowns and bridges. Each has its advantages and disadvantages.

Gold crowns require less tooth tissue preparation but the material is now very expensive.
Porcelain bonded to metal crowns are cheaper but tend to develop a dark line at the crown edge and also look less natural in comparison to other crowns.

All ceramic crowns that contain no metal are presently very strong and offer excellent aesthetics, but can require more tooth removal to achieve this.

Often, the decision is made on the basis of the degree of aesthetics the patient requires and how dark or discoloured the remaining tooth is.

Types of Bridges

 Conventional Bridge

For these, a full coverage crown is prepared on the adjacent tooth or teeth, so there is a need to do substantial reduction to this tooth. The lab technician then makes a crown with a cantilevered blank tooth, very similar to that used in a Maryland bridge. Another design uses a crown at either end of the bridge, so two teeth need preparing.

Maryland or Resin Bonded Bridge (RBB)

It is named after the University of Maryland who pioneered the technique. It relies on using plastics to bond a metal or plastic wing to a tooth.

A bridge unit is made by a dental laboratory to replace the missing tooth with a thin metal or plastic wing that accurately fits the back (palatal or lingual) of an adjacent tooth. The tooth will usually need some adjustment to allow the bite to be correct afterward, but the amount is minimal. The wing is then stuck to the tooth.

In some cases there can be problems with the 'wing' tooth darkening owing to reduced light transmission and an all plastic version is used if this is thought to be likely. It is also possible to make them from ceramic.

Your dentist will discuss with you which bridge type is most appropriate to your individual circumstances.

 What Does the Treatment Involve?

All crowns and bridges involve tooth tissue preparation. Tooth preparation will be done as conservatively as practical.

There are normally two appointments involved with either crown or bridge treatment.

At the first visit the tooth or teeth are prepared and then the dentist will do a 3D scan or take an impression of your upper and lower teeth.

This allows a customised crown or bridge to be created specifically for you. Once the scan is completed satisfactorily, it is sent electronically to a specialist lab.

A shade will also be taken to ensure the best possible match to your existing teeth and a temporary crown(s) or bridge is made and fitted.

In some cases, we ask the patient to attend the laboratory for a shade consultation to ensure the best possible match.

The final appointment is for the crown or bridge to be permanently fitted, using a strong adhesive to ensure maximum strength and adhesion.

This appointment normally lasts for 20 minutes and is scheduled roughly 2 weeks after your scan. This allows plenty of time for the lab to create your new crown/bridge.

Possible Post-Treatment Issues

In general, patients suffer very few issues after crown or bridge treatment. However, a few patients may experience one or more of the following:

Sensitivity of teeth

After the teeth have been prepared or after the crown has been fitted the tooth may become sensitive. It may be mild to severe. Usually there is no to very little sensitivity but if you do get persistent sensitivity please notify us.

Root canal treatment

After being crowned, teeth may develop inflammation or death of the nerve. In most cases this is due to the presenting circumstances of the tooth. It may have been traumatised from an accident, deep decay, extensive fillings or the preparation itself. In this case, the tooth will need root canal treatment and, in some circumstances, referral to a specialist or extraction.

Breakage

Crowns and bridges can chip or break. This is unusual and is not usually due to defective materials or construction unless it occurs soon after placement.

Uncomfortable or strange feelings

This may occur because of the differences between natural teeth and artificial replacements. In the majority of cases, the patient becomes used to the crown or bridge in a matter of weeks.

Aesthetics and appearance

We do our best to get as good an aesthetic result as practicable. Patients will be given the opportunity to observe the appearance of the new crowns and bridges in place prior to final cementation so any adjustments can be readily made.

Longevity of crowns and bridges

There are many variables that determine how long crowns and bridges can be expected to last. Because of this, no guarantees can be made or seen to be made.

We have little control over the pre-existing condition of the underlying tooth, and this is probably the most important factor in survival. Heavily restored teeth may die requiring root canal treatment. Teeth with root canal treatments can become reinfected. Teeth which have had a post fitted to support the crown, can split.

However, despite all the above, the majority of the crowns we supply have a good life span.