Dental Bridge or other options to replace missing teeth
A bridge (fixed partial denture) is an appliance replacing one or more teeth that cannot be removed by the patient. Substantial tooth preparation is necessary for a conventional bridge.
A partial denture (removable partial denture) may be rested entirely on teeth, or be supported by the soft tissues, or by a combination of these two. Rest seats are commonly used, but otherwise it is usually not necessary to prepare the natural teeth extensively. Partial dentures are retained by clasps, by adhesion to the soft tissues, or by dental or soft tissue undercuts.
An implant-retained prosthesis is one retained by osseointegrated implants. A single implant may support a single tooth prosthesis or a series of implants may support a prosthesis replacing a number of teeth. This is usually known as implant supported bridge. The patient cannot remove it, but in some cases the dentist can, by undoing the screws holding the prosthesis to the implants.
Advantages of replacing missing teeth
Appearance: For some patients with teeth missing in the anterior part of the mouth, appearance is an overriding consideration.
Occlusal Stability: If the missing teeth can be replaced before the tooth movements occur and when tooth movements are likely, this may well be sufficient justification for the replacement.
Ability to eat: Many patients manage to eat quite successfully with large numbers of teeth missing. Patients with no lower molar teeth who are fitted with well-designed and well- constructed partial lower dentures frequently leave them out because they claim that it is easier to eat without them. Some patients, though, have a genuine and persistent feeling of awkwardness if they are deprived of even one posterior tooth. As with appearance, the patient’s concept of the problem is as important in deciding on a replacement as the problem itself. Generally though, the more teeth that are missing, the more important is a replacement.
Speech: The upper incisor teeth are the most important in modifying speech, and so when they are missing, they will usually be replaced to improve both speech and appearance.
A feeling of “completeness”
Restoring occlusal vertical dimension: Occlusal collapse with excessive wear or drifting of the incisor teeth sometimes follows the loss of a number of posterior teeth. This is a difficult problem to treat, but in some cases the posterior teeth are replaced by bridges or removable dentures that not only replace the missing teeth but restore the lost occlusal vertical dimension, creating space for the upper incisors to be retracted or crowned as necessary.
Wind-instrument players: with some instruments the mouthpiece is supported indirectly by the teeth, via pressure on the lip. Clearly with these patients not only is the replacement of any missing teeth essential but a bridge will usually be necessary. This must be designed very carefully to reproduce as much of the original contours of the missing teeth as possible.
Disadvantages of replacing missing teeth (with dental bridge)
Damage to tooth and pulp: In preparing teeth for conventional bridges, it is often necessary to remove substantial amounts of healthy tooth tissue. The problem is less serious if the teeth to be used to support the bridge are already heavily restored or crowned. Whenever a tooth is prepared, there is a danger to the pulp, even if proper precautions such as cooling the bur are followed. With some designs, preparations for two or more teeth have to be made parallel to each other, and if the teeth are slightly out of alignment, the attempt to make the preparations parallel may involve more reduction in one part of the tooth than normal and so endanger the pulp.
Secondary caries: As with all restorations, bridges carry the risk of microleakage and caries. This risk is more significant (particularly dento-legally) if the restoration is an elective one rather than the result of caries.
Failures: Patients often ask how long the bridge will last. This is an impossible question to answer, since most bridges do not wear out, neither do the supporting teeth. Failure is the result of an isolated incident, a progressive disease process, or bad planning or execution in the first place. Isolated incidents such as a blow cannot be predicted and may occur on the day the bridge is fitted, in 40 years’ time or never. The prevention of caries and periodontal disease is largely under the control of the patient, assisted and monitored by the dentist and hygienist. Changes affecting caries and periodontal disease likewise cannot be predicted. These include dietary changes, drugs producing a dry mouth and geriatric changes that make cleaning difficult. Some bridges are failures from the day they are inserted and some last for over 40 years. To quote an “average” of 20 years is meaningless.