Saving the Traumatized Tooth: Part II
Diagnosing and treating anterior tooth fracture.

Nothing upsets a patient or the patient’s parents quite so much as a fractured anterior. Despite the shocking appearance ... the blood ... and the discomfort, endodontic treatment is often NOT the best place to start.
Here’s why -

By John I. Ingle, DDS, MSD

In the last article, we discussed proper treatment of a tooth that has suffered a severe blow. In this article, we’ll carry the trauma theme further and discuss tooth fractures.

Tooth-threatening luxations may be hard to diagnose because a tooth that appears relatively normal ... may have a bleak prognosis. For example, a tooth suffering irreversible, unstoppable root resorption may be totally asymptomatic. A fracture, on the other hand, may appear devastating to the patient, yet have a surprisingly positive prognosis.

So the dentist’s first job is to determine the extent of the injury.

With crown fractures there’s usually a chance of concomitant luxation. So even minor fractures should be carefully examined to detect pulpal or periodontal damage, and after treatment, the tooth should be monitored regularly to detect any signs of necrosis.

Is the fracture confined to the enamel? If so, and the amount of missing structure is small, simply smoothing the fractured surface with an ultrafine diamond or Soflex discs may be all that’s necessary.

If the fracture involves both dentin and enamel but not the pulp, a conventional direct or indirect restoration should be placed to restore function and seal exposed dentin to protect the pulp. If the patient brought the fractured component with him or her, it can sometimes be adhesively bonded back in place.

If the crown-fracture involves pulp exposure, your immediate attention should be to the pulpal injury. For an adult patient, one can attempt to preserve the pulp. But a good case can also be made for proceeding directly to root canal treatment - particularly if the exposure is large. The ability of a 40-year-old tooth to recover after a severe exposure is limited. So many dentists feel that performing a pulp-cap on a mature tooth is the triumph of hope over experience.

However, when the patient is young and the tooth still developing, one should make every possible effort to preserve vitality. If the pulp in a developing tooth dies before the apex is fully formed, it will be at high risk of cervical root fracture - probably within just a few years. On the other hand, if vitality can be preserved, the root usually continues to develop and long-term prognosis is excellent. Fortunately, the pulps in young teeth are more vigorous than in older teeth and respond well to vital pulp therapy.

Saving the exposed pulp

The terms “pulp-capping” and “pulpotomy” are sometimes used interchangeably; however, there is an important difference. Pulp-capping refers to the placement of a therapeutic dressing and restorative material directly against a damaged pulp. As the name suggests, “pulpotomy” involves the removal of a small amount of pulp tissue before placement of the cap.

Pulpotomy is the preferable approach because it allows a more secure placement of the capping materials.

In a shallow pulpotomy (figure 6), about 2mm of pulpal tissue is removed using a diamond bur, and the preparation is extended into the dentin. After the wound has been capped with a therapeutic agent, the tooth is adhesively restored to seal the cap and restore function. This “restoration” may be as simple as bonding the broken fragment back in place.

Figure 7: Contrary to popular belief, root
fractures are easy to treat and have an
excellent prognosis.
(Courtesy of Leif K. Bakland)

Historically, calcium hydroxide has been the material-of-choice for capping a pulpotomy. Though it’s excellent for encouraging formation of a dentin bridge, CAOH breaks down in time. This leaves a small gap between the dentin bridge and the restoration. If there is any leakage at all, the gap can jeopardize the treatment by providing sanctuary to bacteria. To eliminate this gap, the initial restoration should be removed after 3 to 6 months - and a new restoration bonded directly to the new dentin bridge.

Because they eliminate CAOH’s gapping problem and the need to replace the initial restoration, new materials, such as mineral trioxide aggregate (MTA - Dentsply/Tulsa Dental) are gaining popularity.

The crown/root fracture

Fractures that involve both coronal and radicular structure often expose the pulp. They are much harder to treat than coronal fractures and have a substantially more guarded prognosis.

If a shattering injury has created multiple fracture lines, extraction may be the only alternative.

If the tooth is fully developed and the crown/root fracture not too complex or too apical, crown lengthening may permit restoration.

Crown/root fracture poses a severe challenge if the tooth is still developing. Since the apex has not yet formed, the vital pulp must be preserved. Unless this is possible via a pulpotomy, there’s little chance of retaining the tooth.

Myths about fractured roots

Root fracture is much less common than crown fracture. And because it’s relatively rare, longtime misconceptions about it have remained unchallenged by personal experience.

For example, many dentists believe that root fracture has a poor prognosis. Wrong! The prognosis is generally quite good. And many believe that most fractured roots require endodontic treatment. Wrong again!

In fact, the best treatment is very conservative.

1) If the coronal segment has been displaced, simply reposition it and stabilize it with a non-rigid splint for 4-6 weeks. This should be sufficient to allow healing of the periodontal membrane and some recalcification of the root. Do not use a rigid splint or immobilize the tooth for longer than 6 weeks, this will encourage root resorption.

2) Carefully monitor healing using radiographs and a pulp-tester. Most cases will heal nicely without further treatment.

Root canal treatment should be considered only if there’s evidence of pulp necrosis. Say, for example, development of osteitis at the fracture site. And even if pulp necrosis does occur, the apical segment generally remains vital. Treating both segments remains an acceptable option if the segments are properly aligned, but it is generally easier to limit cleaning, shaping and filling to the coronal segment.

If the tooth has a large canal, it may be difficult to keep the fill in the coronal segment without extruding out the opening. Here before filling, one may want to stimulate growth of a hard tissue barrier at the apex. If so, you can use calcium hydroxide exactly as you would in an apexification procedure - and then complete treatment after the apex has closed. Or a newer, easier alternative would be to use MTA instead of CH, as the same material would serve as both an apexification stimulant and the canal filling material.

Be alert to alveolar fracture

Though this article is devoted to fractured teeth, I want to go just slightly off-topic and mention the importance of carefully examining the radiographs after any traumatic injury looking for fractures in the alveolus.
If the bone has fractured, it is very important to monitor vitality of the teeth in the fracture line. This is not just to preserve the teeth, but also to preserve the bone. A necrotic pulp can jeopardize healing of the fractured alveolus. Though endodontic treatment is not indicated solely by discovery of an alveolar fracture, any pulp necrosis should be detected early and RCT promptly performed.

The Bottom Line

Granted, a compelling case can be made for performing automatic RCT on a fractured tooth provided the patient is older and the fracture involves pulpal exposure. However, the fact is, many fractured teeth do not require endodontic treatment. In fact, if the root is still developing, RCT shouldn’t even be considered. And root fractures may require nothing more than monitoring.

In the next article we’ll discuss how to save the avulsed tooth.

About the author: Dr. John Ingle is among the world’s most respected endodontists and dental educators. He served as Dental School Dean and Professor of Endodontics and Periodontics at the USC School of Dentistry and was formerly Professor and Chairman of Endodontics and Periodontics at the University of Washington School of Dentistry. He is probably best known to GP’s as co-author of all five editions of the definitive textbook ENDODONTICS and founder of Palm Springs Seminars. He currently lives with his wife in San Diego where he writes and serves on the faculty at Loma Linda University.

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