OLD CROWNS AND BRIDGEWORK
Over the years there has been a tremendous development in dental ceramics for crowns and bridges. New ceramic materials and CADCAM technologies make it possible to fabricate crowns and bridges that really closely mimic the natural appearance of teeth.
In addition, bone and soft tissue augmentation techniques enable rebuilding of the gums around the teeth to produce a much more natural appearance.
This patient is a good example of some of the typical problems seen with failing old crowns and bridges. The pictures on the left show the pre-treatment situation with discolouration and leakage of the old crowns and bridges, an unnatural appearance with poor shape and colour. His upper incisors are also discoloured, worn and damaged. A very typical feature with old bridgework is the shrinkage of the gums and bone ridge that has occurred in the area where teeth have been lost creating a ‘sunken in’ appearance with the bridged teeth sitting on the outside of the gum rather than growing out of the gum as they should be. This can lead to food trapping, makes it harder to clean the teeth well, and of course has an unnatural and ugly appearance.
As you can see from the photographs on the right-hand side after treatment, a beautiful result was achieved after rebuilding the gum and bone in the areas of tooth loss and restoration with new natural-looking crowns on the teeth and some implants to replace the missing teeth. The patient’s upper incisors were also restored with porcelain veneers and a beautiful end result was achieved with natural looking teeth and gums.
What goes wrong with crowns and bridges?
As with all dental work on teeth, crowns and bridges can fail over time as a result of leakage and decay, fracture of the underlying tooth, wear, chipping and fracture of the crown or bridge itself. An additional problem can be the nerve dying in the tooth underneath the crown necessitating root canal treatment. This also sometimes means the crown has to be remade, although the root treatments can often be done through the crown without necessitating a remake. Of course, when old crowns and bridges fail, it may well be possible to make new ones after treating the underlying tooth structure as long as the teeth are sound enough and restorable.
A common challenge of any type of bridgework is the difficulty involved in trying to make the artificial teeth look individual and natural – as if they are actually emerging from your gums like the rest of your teeth. This often requires some soft tissue augmentation or gum grafting. As you can see in the case illustrated above.
Other potential problems with fixed bridgework include the fact that if one of the supporting teeth fails, the entire bridge is vulnerable, plus it is difficult to repair any chips or fractures in the porcelain. This is why dental implants often offer a good alternative as single crowns can be made on the teeth and implants, or bridges on the implants independent of the teeth.