Bridges are restorations cemented in place that are used to replace missing teeth. Getting a bridge is just one of several options for replacing missing teeth (other options are implants and dentures). The option for the material of bridges is the much the same for that of crowns, however the longer the span of the bridge (space between abutment teeth), the more flex it has and the higher the risk for porcelain fracture. Bridges work best when there are solid teeth on either side of the missing tooth. Depending on the quality of the abutment teeth (anchors for the bridge), and the number of pontics (the portion that replaces a tooth) the preparations on abutments may be minimally invasive – similar to a veneer – or more invasive such as a crown. The abutment teeth may be natural or implants. The key to the longevity of bridge work is cleanliness and strong abutment teeth. When making the decision to get a bridge, it is very common for people to consider its lower cost and better coverage by insurance, than that an implant. We tend to caution against this line of thinking, as it is not uncommon for another tooth to be lost when a bridge finally does fail, and the future replacements cost is often higher than that of an implant done from the start. Forces also need to be taken into account when deciding on a bridge. You have to remember that for each tooth being replaced, all that biting-force is now added to the anchor teeth. So if two teeth are being replaced using two anchor teeth, those teeth are now going to experience double their normal force, which can severely compromise their lifespan.

Bridges

5 Unit Bridge Replacing 2 Teeth

As mentioned above, when a bridge fails it can often take another tooth with it. This patient had an existing 3 unit bridge and one of the anchor teeth rotted out underneath. In order to preserve this patient’s smile the old bridge was removed, a bad tooth extracted, and a new bridge prepared. As the new bridge was to replace two missing teeth, the bridge was extended to anchor onto two teeth in the back and one in the front in order to distribute the forces as much as possible. The final result was a great smile. The photos show the process from the initial bridge to the final bridge. In the prepared bridge photo, the dark area on the gums is from the decayed tooth that was removed right after the photo was taken. You can also see in the photos the extent of bone loss from the missing teeth by how high up the bridge has to go. Fortunately, it does not show when smiling.

5 Unit Implant Supported Bridge With 3 Implants

When multiple teeth are missing in a row, a bridge anchored on natural teeth may not work very well. An option available is to do a bridge over multiple implants, which can significantly reduce the cost of replacing each individual tooth with individual implants. In this case, the patient had a partial denture but wanted something fixed in place. Implant placement was chosen (span too long to provide a long-lasting bridge on natural teeth). Three implants were placed and a 5 unit bridge fabricated to cement to them. The gold posts you see are the custom attachments anchored onto the titanium screw embedded into the bone. Also, note this bridge runs flush with the gum-line in order to minimize airflow and food collection. Unfortunately, it is more challenging to clean when done this way.

Bridges
Bridges

3 Unit Hygienic Bridge

One of the ideal cases for bridges is when a single tooth needs replacement, and the neighboring teeth are good and solid. This case is a perfect example. In situations like this, we have the added option of a different bridge design to aid in bridge maintenance. The hygienic pontic can be shortened to leave a space underneath it to aid in access for cleaning and monitoring the edges of the bridge. As you may suspect, more food will get into this area because of the gap, but the long-term benefits of its ability to be easily cleaned and maintained make it very worthwhile.

3 Unit Hybrid Bridge

When using bridges it is good to be as conservative as possible. Not all cases require grinding down an entire tooth in order to anchor the bridge, and this case is one such example. The tooth behind the space was a pretty solid tooth but had a good-sized filling in it lending it to be a good candidate for a future crown. The tooth in front of the space was a solid tooth, for which it would be a shame to grind it down for a standard bridge. The decision was made to do a standard bridge abutment on the tooth on the left, but only do a metal plate bonded to the inner surface of the tooth on the right (hence the transition line from pontic to the tooth on the right). To do this, only minor tooth structure removal was required on the right tooth, just enough to help brace the bridge.

Bridges