Bridges

When a tooth has been lost one of the ways to replace it is by using a bridge.

A bridge involves preparing each tooth adjacent to the gap for crowns. The crowns that are made are joined together by a fake tooth in between them. They “bridge” the gap. (Each tooth in a bridge, real or fake, counts as a ‘unit.’

As with crown preparations, the teeth are first “reduced” in order to make space the bridge to go over the teeth. Then a mould or ‘impression’ is taken which is sent to the technician/lab. A temporary bridge is made for the patient to wear during the next two weeks while the technician fabricates a unique custom fit bridge. The bridge is a rigid, one-piece cast gold core, with porcelain/ceramic baked to the outside for esthetics. After it is completed the temporary bridge is removed and the custom bridge is usually permanently cemented into place. If it is in an esthetic area or the supporting teeth have not settled it may be cemented temporarily for a period while the esthetics get sorted.

Advantages to bridges over other tooth replacement options are:

  1. Fast turnaround time. An hour and a half preparation visit and two weeks later a 30-minute cementation visit if all goes well.
     
  2. Dental insurance companies often include this in services they cover and may pay half the costs.
     
  3. If the adjacent teeth have already had huge fillings placed in them then a bridge can serve to protect these against future breakage as well as fill in the missing tooth.
     
  4. If in the “smile zone” they may be able to correct colour as well as do a certain amount of tooth ‘repositioning’ to make teeth look straighter and better then they may have before.

Disadvantages:

  1. The adjacent teeth have to be reduced. This is an issue if these teeth are in pristine condition.
     
  2. There may be a sensitivity to Hot/cold in the area of the bridge. It may be necessary to microwave your beer for a few weeks or even a month or two!
     
  3. The possibility of one of the supporting teeth needing a root canal because the ‘trauma’ of the reduction somehow causes the nerve to die.
     
  4. Getting the esthetics right if in the esthetic zone, especially for people with high smile lines (‘gummy smiles’).
     
  5. Cleaning properly under the bridge – most common failures are due to decay under the bridge in the long term.
     
  6. Porcelain fracturing off in the long term due to something really hard being bitten on, or the bridge flexing because the teeth tend to move up and down in their sockets. Also, the longer a bridge is the more it flexes in the middle.
     
  7. Bridges are best restricted to replacing no more than one missing tooth. The problem is the remaining teeth now do more work as the work of the missing tooth/teeth are now added to their load.
     
  8.  Clenchers and grinders especially will put extra strain onto bridgework

Other options to replace missing teeth are removable partial dentures or BETTER; place one or more implants depending on the situation.
 

A3_unit_bridge_with_nomenclature.png

A 3 unit bridge with nomenclature.

Underside_of_a_porcelain_fused_to_precious_metal_Bridge.png

The underside of a porcelain fused to precious metal.