Children

Dental trauma, permanent teeth

Trauma to permanent teeth is most common during athletic activities, and usually involves the upper incisor teeth. The severity of the injury depends on which tissues are involved (enamel, dentin, pulp, periodontal ligament, alveolar bone), and the tooth's stage of development. The extent of tissue damage depends on how the forces on the tooth are directed, and how the teeth are positioned in the jaw. Incisors that protrude facially are more vulnerable to chipping than those with a normal inclination.

Preventing Dental Trauma in School-Aged Children

If your child has teeth which develop in a position that is tipped forward or backward significantly from normal alignment in the dental arch, have them evaluated by a dentist or orthodontist as soon as feasible. It is often possible to return the teeth to near normal position with simple "active" retainers that use springs and/or wires to apply gentle tipping forces to the malpositioned teeth.
Learn more: Procedures › Orthodontics
Learn more: Diagnoses › Malocclusion

Protect the teeth with an athletic mouthguard during all sporting activities that have the potential to cause dental injuries. It is important to realize that regardless of whether short term success is achieved through treatment of injured teeth, the likelihood of developing future problems (e.g. abscess, pulp space obliteration, external resorption, internal resorption) is greater for injured teeth than for uninjured teeth. This is true even after several years have passed without complications.
Learn more: Procedures › Athletic mouthguards

Incompletely Developed Permanent Teeth—a Special Case

Injuries can be more complicated in incompletely developed permanent teeth, because the root(s) may not be completely formed. This means the root tips do not taper to a fine point, and the blood vessels do not enter the tooth through a tiny opening in the root tip. Incompletely developed teeth have a wide-open apex, and much better blood circulation to the root tip. Thus, the living tissues of the pulp are generally more capable of surviving a traumatic event.

When an incompletely developed tooth sustains an injury in which the pulp is involved, the goal is to keep the pulpal tissues alive—at least long enough to complete the development of the root. The dental procedure for doing this is known as apexogenesis. Frequently the pulpal tissues of developing teeth do survive the traumatic event, because of their wide open root apex, increased blood flow to the tooth, and the fact that blood is not supplied to an enclosed, rigid housing like that of a fully developed tooth.

Apexogenesis

Apexogenesis involves locally anesthetizing the tooth so that it can be treated comfortably. A rubber dam is used to isolate the tooth from mouth moisture and oral bacteria. Using sterile instrumentation, the pulpal tissues are removed from the crown of the tooth, but are left in place in the tooth's root. This incomplete removal of the pulp is known as a pulpotomy.

Some dentists prefer to leave a millimeter or two of vital pulp tissue in the crown of the tooth (if it isn't inflamed) to allow for future vital testing—application of cold substances or mild electrical current to see if there is living nerve tissue in the tooth. A medicated plug of medical grade calcium hydroxide is placed over the remaining pulp tissues of the root. Calcium hydroxide is used because of its anti-microbial effects and its ability to induce calcium deposition at the insertion point. The medicated plug is then hermetically sealed into the tooth, often with a tooth-colored composite resin filling.

Usually, the filling that is placed over the medicated plug is intended to be temporary, although they can be made to look remarkably esthetic. The tooth is followed closely for several months, with exposure of periapical X-ray images at regular intervals, to assess the progress of root completion and ensure that infection or inflammation of the root tip has not occurred.

When root development is complete, the medicated plug is typically removed, and traditional endodontic (root canal) treatment is performed to prevent the root canal space from being completely calcified. Placement of a rubbery gutta percha root canal filling allows for later placement of a structural post if necessary.

Apexification

If a developing permanent tooth is too badly damaged or inflamed for any of the pulp tissues inside it to remain alive and uninfected, the dentist can attempt procedures to build a calcium plug at the end of the existing root, in order to fully enclose and seal it against future bacterial invasion. This procedure for doing this is known as apexification. If the procedure is not successful, the incompletely developed root will have a wide open "blunderbuss apex". In such cases, placement of a rubbery gutta percha root canal filling will be difficult or impossible to achieve.

Apexification involves locally anesthetizing the tooth so that it can be operated on comfortably. A rubber dam is used to isolate the tooth from mouth moisture and oral bacteria. Using sterile instrumentation, the pulpal tissues are completely removed from the crown and root canal to the existing apex of the incompletely formed tooth. This complete removal of the pulpal tissues is known as pulpectomy.

Care is taken not to file on the already thin walls of the developing tooth. A plug of medical grade calcium hydroxide is generally placed in the tooth near the apex to stimulate closure of the open root tip by living cells occupying an expanse of tissue around the developing root tip known as Hertwig's epithelial root sheath. Calcium hydroxide is used because of its anti-microbial effects and its ability to induce calcium deposition at the root tip. Current studies are underway to investigate the use of Mineral Trioxide Aggregate (MTA), a medical grade Portland cement, as an alternative to calcium hydroxide for apexification procedures.

Once the medicated plug is placed near the developing root apex, a temporary filling is placed in the crown of the tooth to prevent bacteria from getting inside the tooth during root completion. The filling can be made to look remarkably esthetic.

When the apexification process is complete (several months later), the temporary filling is removed and conventional endodontic (root canal) treatment is performed to seal the tooth against future bacterial invasion. Depending on how much damage was done to the tooth's crown, a permanent filling, onlay or crown will typically be placed as the final restoration.

It is important to realize that teeth which require apexification will have very thin dentin walls at their apex, which is structurally weaker than a fully developed root. This is because the cells that make and deposit dentin die when the rest of the pulp tissues die. The resulting thin walls make the tooth more vulnerable to future fractures.

Direct Pulp Cap

Injuries to developing permanent teeth in which a very small pulp exposure occurs can sometimes be treated without removing any of the tooth pulp. The dental procedure for this is known as a direct pulp cap. However, conditions must be ideal for the tooth to be treated in this way. It must be treated within a couple of hours of the injury, and must not be hemorrhaging or inflamed. Chances of the pulp healing decrease if the tissue is inflamed, has formed a clot, or is contaminated with foreign materials from the injury.

Even under ideal circumstances, treating the tooth without removing the pulp may ultimately be unsuccessful. It may become infected (an abscess develops) and require apexogenesis or apexification procedures before conventional endodontic (root canal) treatment can be performed. Some dentists prefer to perform apexogenesis procedures due to the limited circumstances under which direct pulp caps may be successful.

Direct pulp capping involves locally anesthetizing the tooth so that it can be operated on comfortably. A rubber dam is used to isolate the tooth from mouth moisture and oral bacteria. The exposed pulp tissue is gently cleaned with sterile water, and the tooth fracture margins are smoothed to eliminate sharp edges and weak, unsupported enamel. Some dentists will apply a small amount of dilute chorhexidine to disinfect the tooth. A dentin bonding agent may or may not be used, depending on the dentist.

A small amount of medical grade calcium hydroxide is applied directly to the exposed pulp and dentin around the fracture. The medicated calcium hydroxide plug is then hermetically sealed into the tooth with a bonded, tooth-colored, composite resin filling, sculpted to resemble the uninjured tooth. Depending on how much of the tooth's crown was lost in the fracture, the filling can be a long term restoration, and can produce outstanding cosmetic results. In other cases, a crown, onlay, or veneer may be recommended as the best long term solution. It is often possible to restore only one tooth and achieve excellent cosmetic results.

If a direct pulp cap procedure is successful, a bridge of calcified reparative dentin can be seen on an X-ray image of the tooth at approximately 2-3 months following the injury. Close follow-up is generally recommended for injured teeth to be sure an infection has not developed in the jaw, and that inflammatory root resorption (a chronic state of inflammation) is not dissolving the root away. If either condition is noted, the tooth generally requires conventional endodontic (root canal) treatment to save it.
Learn more: Procedures › Cosmetic restorations, one tooth
Learn more: Procedures › Endodontic treatment
Learn more: Diagnoses › Chipped teeth

Subluxation of Fully Developed Permanent Teeth

When fully developed permanent teeth are displaced slightly (subluxated) from their normal position in the jaw, pulp death (necrosis) is more common than it is for incompletely developed permanent teeth and primary teeth. If pulp death occurs, the tooth generally requires endodontic (root canal) treatment to save it. Minor lateral luxation injuries are generally not splinted, or fusion to the jaw bone (ankylosis) may occur. It may be necessary for the dentist to gently reposition the tooth manually to avoid functional problems with the patient's bite (occlusion).

Luxation Injuries (Incompletely and Fully Developed)

Fully developed permanent teeth which are displaced far enough to fracture the tooth-supporting (alveolar) bone are generally repositioned manually by a dentist, along with any broken fragments of alveolar bone. They are then splinted to the adjacent teeth to stabilize the fracture for two or more weeks, depending on the severity of damage to the bone. If the root is fully developed, the pulp will often die, and endodontic (root canal) treatment is generally recommended as soon as the tooth is splinted.

The repositioning and splinting procedures for incompletely developed permanent teeth are generally the same as for fully developed permanent teeth. However, if the root is not fully developed, the pulp should be monitored instead of routinely removed. There is some chance that the pulp of displaced teeth with open root tips will not die (necrose). If it does, apexification procedures may be recommended, followed by traditional endodontic (root canal) treatment.

Luxation of permanent teeth may damage or destroy part or all of the periodontal ligament, and cause bone loss around the tooth to occur. It is also common for luxated or avulsed teeth to undergo replacement resorption (ankylosis) when periodontal ligament damage occurs.

Intrusion Injuries

Permanent teeth which have been driven into the jaw bone along their long axis, such that the tooth's crown appears shorter, have an uncertain long term prognosis. In such cases, damage to the nerve and blood vessels entering the tooth generally leads to pulp death. Damage to fibers of the periodontal ligament and tooth-supporting alveolar bone often leads to an aggressive inflammatory response by the body, which can dissolve away the root in a process called inflammatory resorption. Sometimes the alveolar bone itself may also resorb.

Treatment for intruded permanent teeth generally involves orthodontic extrusion of the injured tooth with light forces, whether or not its roots are fully developed.

Fully Developed Permanent Teeth

A pulpectomy (complete removal of the pulp) is often performed on fully developed permanent teeth, and medical grade calcium hydroxide is placed into the tooth to suppress the inflammatory response that can lead to root resorption. It may be necessary to change the calcium hydroxide medication several times over a period of one to two years, and the tooth is typically monitored at regular intervals during that time period by exposing periapical X-ray images to check for signs of resorption. Traditional endodontic (root canal) treatment is generally recommended when avoidance/suppression of resorption appears successful.

Incompletely Developed Permanent Teeth

If the intruded permanent tooth's roots are not fully developed, apexogenesis may be recommended to stimulate completion of root formation, and to suppress the inflammatory response that may otherwise resorb the tooth root. After root formation is complete, traditional endodontic (root canal) treatment is generally recommended. The tooth will need to be monitored long term for signs of resorption.

Avulsion injuries (tooth knocked completely out)

Information about avulsed permanent teeth is located under Symptoms.
Learn more about avulsion of permanent teeth: Symptom checker › Avulsion injuries