Trauma livro antigo endodontic considerations in dental trauma chapter 15 by Louize Lobato

Chapter 15 ENDODONTIC CONSIDERATIONS IN DENTAL TRAUMA Leif K. Bakland

The outcome of traumatic events involving teeth depends on three factors: the extent of injury, the quality and timeliness of initial care, and the follow-up evaluation and care. The extent of injury is influenced by the severity of the traumatic event1 and the presence or absence of protective gear such as mouthguards, face shields, airbags, and seatbelts.2 Direction of force against the teeth and supporting structures and the type of impact—blunt or sharp—also can determine how much tissue damage will result. It is well recognized that preventive measures such as tooth and face protection during sporting events and seatbelts and airbags used in cars can significantly reduce the severity of injuries.2 The quality and timeliness of initial care contribute to a desirable outcome by promoting healing. A good example is the avulsed tooth: if it is replanted within the first few minutes after avulsion, the prognosis is good, with a high rate of success.3 It is important to note, however, that the quality of initial care also is important. As Andreasen has pointed out, the initial treatment should not add more trauma to already injured tissues.4 A good example of this principle is with respect to luxated teeth: the repositioning of displaced teeth and adjacent tissues must be done very gently to promote desirable wound healing and longterm favorable outcome. Follow-up evaluation and care are important components of long-term successful outcomes.1 A replanted avulsed tooth may show an excellent initial response—healing of the severed periodontal ligament—but if the necrotic pulp is allowed to harbor bacteria, the resultant root resorption will lead to loss of the tooth. Often the long-term outlook for a traumatized tooth is related to the response of the tooth’s pulp—thus the importance of endodontic considerations in dental trauma.

This chapter contains information both on the preservation, when indicated, of pulp vitality after a traumatic injury and the appropriate endodontic intervention when pulp necrosis is present or expected. ETIOLOGY AND INCIDENCE Sudden impact involving the face or head may result in trauma to the teeth and supporting structures. The most frequent causes are falling while running, followed by traffic accidents, acts of violence, and sports.5 Automobile accidents are often very destructive. One estimate suggests that 20 to 60% of all traffic accidents produce some injury to the facial regions. When such injuries involve teeth, avulsions or intrusions are the most common sequelae.6 Sports activities, both team and individual, can lead to dental injuries, which have been shown to be common in high school athletes who do not use mouthguards.7 The incidence of dental trauma continues to be investigated. A large US study indicated that 25% of the population 6 to 50 years of age may have sustained traumatic injuries to the anterior teeth.8 Surprisingly, some are unaware of their dental injuries, and many choose not to seek dental treatment. Most dental injuries occur during the first two decades of life. The most accident-prone time period is from ages 8 to 12 years. Frequent dental injuries also occur from ages 2 to 3 years.5 As might be expected, boys tend to injure their teeth more frequently than girls, by ratios varying from 2:1 to 3:1. One exception is in the preschool age, during which time little gender difference is noted.5 Maxillary central incisors, followed by maxillary lateral incisors and then the mandibular incisors, are the teeth most frequently involved.5 The most commonly observed dental trauma involves fracture of enamel, or enamel and dentin, but without pulp involvement.5

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Finally, it is becoming apparent that dental injuries can result from child abuse or “battered child syndrome.” The dentist may be the first health care provider to observe pediatric injuries resulting from abuse. More than half of the reported cases of child abuse include evidence of orofacial trauma. Many of these unfortunate children have intraoral injuries, such as tooth and jaw fractures. It is the responsibility of all professionals to report suspected cases of child abuse or neglect.9 The following observations have been recommended as possible indicators of an abused child; none, however, are pathognomonic, and the absence of any of them does not preclude the diagnosis of abuse10: 1. There is a delay in seeking medical (dental) help (or help is not sought at all). 2. The story of the “accident” is vague, is lacking in detail, and may vary with each telling and from person to person. 3. The account of the accident is not compatible with the injury observed. 4. The parents’ mood is abnormal. Normal parents are full of creative anxiety for the child, whereas abusing parents tend to be more preoccupied with their own problems—for example, how they can return home as soon as possible. 5. The parents’ behavior gives cause for concern—for example, they may become hostile and rebut accusations that have not been made. 6. The child’s appearance and interaction with the parents are abnormal. The child may look sad, withdrawn, or frightened. 7. The child may say something concerning the injury that is different from the parents’ story. Most hospitals have personnel who can offer advice to health care providers unsure about how to report suspected abuse. CLASSIFICATION The purpose of classifying dental injuries is to provide a description of specific conditions, allowing dentists to recognize and treat using recommended treatment remedies. It also allows data collection worldwide to monitor many aspects of dental traumatology: etiology, incidence, and treatment outcome. The currently recommended classification is one based on the World Health Organization classification of diseases and modified by Andreasen and Andreasen. 5 This classification is used by the International Association of Dental Traumatology and is preferred over previous outdated systems.11 It

is also the classification that will be followed in this chapter (Table 15-1). EXAMINATION Patients with dental injuries should be examined as soon after the traumatic incident as possible.12,13 The examination process of trauma patients is similar to the regular examination of all endodontic patients, as described in chapter 6. However, owing to the possibility of concomitant injury to adjacent tissues and the frequent need to provide insurance and/or a legal report, it is prudent to pay particular attention to a careful examination and recording of clinical findings. For that reason, the following sections have been given emphasis. History The clinical dental history is primarily the subjective statement by the patient. It includes the chief complaint, history of the present illness (injury), and pertinent medical history. Chief Complaint The chief complaint may appear obvious in traumatic injuries. However, the patient should be asked about severe pain and other significant symptoms. A bloody lip appears more dramatic, but a concomitant broken

Table 15-1

Dentofacial Injuries

Soft tissues Lacerations Contusions Abrasions Tooth fractures Enamel fractures Crown fractures—uncomplicated (no pulp exposure) Crown fractures—complicated (with pulp exposure) Crown-root fractures Root fractures Luxation injuries Tooth concussion Subluxation Extrusive luxation Lateral luxation Intrusive luxation Avulsion Facial skeletal injuries Alveolar process—maxilla/mandible Body of maxillary/mandibular bone Temporomandibular joint

Endodontic Considerations in Dental Trauma jaw may produce more pain and must be considered a higher priority. The chief complaint may include several subjective symptoms, and these should be listed in order of importance to the patient. Also note the duration of each symptom. History of Present Illness (Injury) Obtain information about the accident in chronologic order and determine what effect it has had on the patient. Note any treatment before this examination and question the patient about previous injuries involving the same area. The information can be gathered by using questions such as the following: • When and where did the injury happen? Record the time and date as closely as the patient can recall. Note the location, for example, playground, car accident, etc. All of this may be highly pertinent if legal or insurance problems later develop. • How did the injury happen? This question can provide important information. A blow to the face by a blunt object, such as a fist, often produces a different injury than if the chin is hit during a car accident or if the patient falls off a bicycle.14 Further, since children with “battered child syndrome” may be seen, a high degree of suspicion should be maintained in cases with a marked discrepancy between the clinical findings and the history supplied by the parent or guardian.10,11 • Have you had treatment elsewhere before coming here? Prior treatment affects both the treatment plan and the prognosis. If the tooth was avulsed, was it replanted immediately or how soon after the accident? Was it washed? • Have you had similar injuries before? Repeated injuries to teeth affect the pulps and their ability to recover from trauma. Previous trauma may also explain clinical findings not in harmony with the description of the most recent injury. This is particularly true of abused children. • Have you noticed any other symptoms since the injury? This type of question can provide very useful information about the possible effects of the injury on the nervous system. Signs and symptoms to watch for are dizziness; vomiting; severe headaches; seizures or convulsions; blurred vision; unconsciousness; loss of smell, taste, hearing, sight, or balance; or bleeding from the nose or ears. Affirmative response to any of the above indicates the need for emergency medical evaluation.12 • What specific problems have you had with the traumatized tooth/teeth? Pain, mobility, and occlusal

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interference are the most commonly reported symptoms. In addition, the patient should be asked about any symptoms from adjacent soft tissues such as tongue, lips, cheeks, gingiva, and alveolar mucosa. Medical History The following aspects of the medical history are emphasized for their importance in trauma cases: 1. Allergic reactions to medications. Because both antibiotics and analgesics are frequently prescribed for trauma patients, it is necessary to know if the patient can tolerate the prescribed medication. 2. Disorders, such as bleeding problems, diabetes, and epilepsy. These are only some of the many physical and medical conditions that may affect the management of a trauma patient. Because patients with medical problems sometimes neglect to note such a disorder on the questionnaire, the dentist may have to question in more depth. Patients suffering from grand mal epilepsy, for example, may have telltale chipped or fractured teeth that were injured during seizures. 3. Current medications. To avoid unwanted drug interactions, the dentist must know which drugs the patient is currently taking, including over-thecounter medications. 4. Tetanus immunization status. For clean wounds, no booster dose is needed if no more than 10 years have elapsed since the last dose. For contaminated wounds, a booster dose should be given if more than 5 years have elapsed since the last dose.15 Clinical Examination A careful, methodical approach to the clinical examination will reduce the possibility of overlooking or missing important details. The following areas should be examined. Soft Tissues Soft tissue trauma, for the most part, is not covered in this chapter, at least not in regard to treatment, such as suturing. It is important, however, to examine all soft tissue injuries because it is not unusual for tooth fragments to be buried in the lips. The radiographic examination should include specific exposures of the lips and cheeks if lacerations and fractured teeth are present (Figure 15-1). In any event, all areas of soft tissue injury should be noted, and the lips, cheeks, and tongue adjacent to any fractured teeth should be carefully examined and palpated.

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B Figure 15-1 A, Lacerated lips and cheeks should be radiographed for embedded tooth fragments. B, Radiograph placed lingual to the lower lip exposed about one half that used for teeth and shows a hard tissue fragment embedded in the lip. C, Lateral film also demonstrates a tooth fragment in the lip (arrow).

Facial Bones The maxilla, mandible, and temporomandibular joint should be examined visually and by palpation, seeking distortions, malalignment, or indications of fractures. Indications of possible fractures should be followed up radiographically. Also note possible tooth dislocation, gross occlusal interference, and development of apical pathosis. Teeth The teeth must be examined for fractures, mobility, displacement, injury to periodontal ligament and alveolus, and pulpal trauma. Remember to examine the teeth in the opposite arch also. They, too, may have been involved to some degree. Tooth Fracture The crowns of the teeth should be cleaned and examined for extent and type of injury. Crown infractions or enamel cracks can be detected by changing the light

beam from side to side, shining a fiber-optic light through the crown, or using disclosing solutions. If tooth structure has been lost, note the extent of loss: enamel only, enamel and dentin, or enamel and dentin with pulp exposure. Further, indicate the exact location on the crown, such as the “distal-incisal corner” or the “incisal one-third horizontal.” Such information can be useful if you are called on later to describe the injury. Photographs are very useful as part of the patient record.12 If a crown fracture extends subgingivally, the fractured part often remains attached but loose. Also check for discoloration of the crown or changes in translucency to fiber-optic light. Both may indicate pulp changes. Mobility Examine the teeth for mobility in all directions, including axially. If adjacent teeth move along with the tooth being tested, suspect alveolar fracture. Root fractures often result in crown mobility, the degree depending on

Endodontic Considerations in Dental Trauma the proximity of the fracture to the crown. The degree of mobility can be recorded as follows: 0 for no mobility, 1 for slight mobility, 2 for marked mobility, and 3 for mobility and depressibility. Examine for and record the depths of any periodontal pockets. Displacement Note any displacement of the teeth that may be intrusive, extrusive, or lateral (either labial or lingual) or complete avulsion. Sometimes the change is minimal, and the patient should be asked about any occlusal interference that developed suddenly. In occlusal changes, consider the possibility of jaw or root fractures or extrusions. Injury to Periodontal Ligament and Alveolus The presence and extent of injury to the periodontal ligament and supporting alveolus can be evaluated by tooth percussion. Include all teeth suspected of having been injured and several adjacent and opposing ones. The results may be recorded as “normal response,” “slightly sensitive,” or “very sensitive” to percussion. Careful tapping with a mirror handle is generally satisfactory. In cases of extensive apical periodontal damage, however, it may be advisable to use no more than a fingertip for percussion. Normal, noninvolved teeth should be included for comparison. In impact trauma with no fractures or displacement, the percussion test is very important. In some apparently undamaged teeth, the neurovascular bundle, entering the apical canal, may have been damaged, and the possibility of subsequent pulp degeneration exists. Such teeth are often sensitive to percussion. Pulpal Trauma The condition of the dental pulp should be evaluated both initially and at various times following the traumatic incident. The response of the pulp to trauma largely determines the treatment of and prognosis for injured teeth. Often the initial treatment may be no treatment but rather monitoring of the pulp response. Pulps may deteriorate and become necrotic months or years after the original trauma, so periodic re-evaluation is important in the management of dental injuries.1 Several means of evaluating traumatized pulps are available.1,12 The electric pulp test (EPT) has been shown as reliable in determining pulpal status, that is, in differentiating between vital and necrotic pulps. The EPT should be used, and the results recorded, at the initial visit and at subsequent recall visits. Often, after an impact injury, the pulp does not respond to the EPT

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for some time. But when the pulp recovers, its sensitivity to the EPT gradually returns. Such recovery can be monitored with the test. Other times, the pulp later becomes necrotic after initially responding positively or even after apparent recovery from the initial injury. The EPT can provide much useful information if its advantages, as well as its limitations, are considered. Cold stimulus in the form of carbon dioxide or ice is used extensively for pulp testing and is quite reliable. The response, however, is not easily quantified. The usefulness of cold is most applicable in differentiating between reversible and irreversible pulpitis. Hot stimulus has limited use in pulp testing traumatically injured teeth. However, subjective symptoms can be useful, particularly a history of spontaneous pain, indicating irreversibility. Discoloration, particularly a grayish hue, involving permanent teeth is indicative of pulp necrosis, whereas a yellowish hue means that extensive calcification has occurred. The latter is not necessarily associated with irreversible pulpitis or pulp necrosis.16,17 Radiographic Examination Radiography is indispensable in the diagnosis and treatment of dental trauma. Detection of dislocations, root fractures, and jaw fractures can be made by radiographic examination. Extraoral radiography is indicated in jaw and condylar fractures or when one suspects trauma to the succedaneous permanent teeth by intruded primary teeth. Soft tissue radiographic evaluation is indicated when tooth fragments or possible foreign objects may have been displaced into the lips, for example see Figure 15-1. The film should be placed between the lip and the jaw, and short exposure at minimal KVP is advocated.12 The size of the pulp chamber and the root canal, the apical root development, and the appearance of the periodontal ligament space may all be evaluated by intraoral radiographs. Such films are of prime importance both immediately after injury and for follow-up evaluation.18 Changes in the pulp space, both resorptive and calcific, may suggest pulp degeneration and indicate therapeutic intervention (Figure 15-2). Other radiographic views may be indicated in more extensive injuries than those confined to the dentition. Finally, it is also important to carefully file all radiographs for future references and comparisons. Follow-up Evaluation Trauma patients should be evaluated often enough, and over a long enough period of time, either to determine that complete recovery has taken place or to

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A Figure 15-2 Subsequent to trauma one central incisor (a) shows pulpal calcification, whereas the adjacent one (b) undergoes internal resorption (arrow). The latter requires endodontic intervention, whereas pulpal calcification in and of itself does not.

detect as early as possible pulpal deterioration and root resorption. If pulpal recovery (eg, revascularization) is to be monitored, frequent initial re-evaluations (every 3 to 4 weeks for the first 6 months) and then yearly are recommended.1,11 Radiographs and pulp testing should be included in the evaluations. If inflammatory resorption or pulp necrosis occurs, endodontic treatment is indicated immediately (Figure 15-3). In permanent teeth, pulp necrosis should be suspected in the presence of a graying crown discoloration, no response to the EPT, and radiographic indication of apical periodontitis. A lack of response to the EPT alone is not sufficient to diagnose pulp necrosis and recommend pulpectomy.19 Root canal therapy may be indicated if the pulp lumen diminishes at a rapid pace, as determined by radiographs taken at frequent intervals. No general agreement exists, however, about this indication for treatment.19 Examination of Old Injuries At times, patients request treatment of dental conditions, the etiology of which is uncertain. For instance, an anterior tooth with no restorations and no loss of tooth structure may develop symptoms of pulp necrosis and apical periodontitis (Figure 15-4). Some

B Figure 15-3 Extensive resorption (arrow) following trauma. Such destructive results can often be minimized by timely endodontic intervention.

patients may not remember any traumatic incidents, whereas others may recall specific accidents but only after lengthy efforts at memory recall or after discussions with their families. Some may have received treatment at the time of injury but somewhat later developed new symptoms. In this case, the dental history and chief complaint will be related to the current symptoms. Information suggesting previous trauma as the etiology would include crown discoloration, gingival dehiscence, reduced pulp canal lumen, root resorption,

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B Figure 15-4 Maxillary left central incisor developed an apical abscess 30 years after a traumatic basketball accident. A, Note labial swelling (open arrows) and B, apical radiolucency. Pulp did not respond to an electric pulp test, and the crown was slightly discolored.

Figure 15-5 A, Fistulous tract traced with gutta-percha point from labial orifice to B, apical lesion.

and pulp necrosis not related to other obvious causes such as caries and/or tooth infractions. Sinus tracts are sometimes the first indication of a previous injury; these tracts should be traced to identify areas of origin (Figure 15-5).

Tooth Fractures

TRAUMATIC INJURIES Soft Tissue Injuries Description. Injuries to oral soft tissues can be lacerations, contusions, or abrasions of the epithelial layer or a combination of injuries.1 If treatment is indicated, it consists of controlling bleeding, repositioning displaced tissues, and suturing. Oral soft tissues heal rather quickly.

This category of injuries includes all fractures from enamel infractions to complicated crown-root fractures. They are the most commonly reported types of dental injuries, with an incidence of 4 to 5% of the population (United States)8,20 accounting for over onethird of all dental trauma.21 Enamel Fractures Description. Enamel fractures include chips and cracks confined to the enamel and not crossing the enamel-dentin border. These enamel infractions22 can be seen by indirect light or transillumination or by the

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use of dyes. In anterior teeth, the enamel chips often involve either the mesial or distal corners or the central lobe of the incisal edge.22 When treatment is indicated, it involves minor smoothing of rough edges or adding some composite resin using the acid-etch technique. One other consideration needs mentioning. Since it is difficult to predict the long-term pulpal response to trauma, pulp vitality tests should be performed both immediately after the injury and again in 6 to 8 weeks.22 It must be kept in mind that, even with minor traumatic injuries, such as enamel fractures, damage to the apical neurovascular bundle may have occurred (Figure 15-6). The prognosis, however, for teeth with enamel fractures is very good.22 Crown Fractures—Uncomplicated (No Pulp Exposure) Description. Crown fractures involving enamel and dentin without pulp exposure are called uncomplicated crown fractures by Andreasen5 and Class 2 fractures by Ellis.23 They may include incisal-proximal corners, incisal edges or lingual “chisel”-type fractures in anterior teeth, and, frequently, cusps in posterior teeth. Cusp fractures in posterior teeth are often related to blows to the face. Because anterior teeth are more often involved in traumatic injuries, the description in this chapter will refer only to these teeth. Crown fractures that expose dentinal tubules may potentially lead to contamination and inflammation of the pulp. The outcome may be either formation of irritational dentin or pulp necrosis. Which outcome occurs depends on a number of factors: proximity of the fracture to the pulp, surface area of dentin exposed, age of the patient (pulp recession and size of dentinal tubules), concomitant injury to the pulp’s blood supply, length of time between trauma and treatment, and possibly the type of initial treatment performed.1, 22 Incidence. The enamel/dentin type of crown fracture is a very common type of injury; a distinction, however, is not always made between fractures involving only enamel and those involving both enamel and dentin. The two groups together certainly comprise the vast majority of dental injury cases.8,20,21 Diagnosis. The diagnosis of crown fracture without pulp involvement is made by clinical examination with a mirror and an explorer. In addition, it is also important to determine the status of the pulp and periradicular tissues by the usual examination procedures. Treatment. The primary goal of treatment in teeth with crown fractures is to protect the pulp by sealing the dentinal tubules.24 The most effective method is by direct application of dentin bonding agents and bond-

B Figure 15-6 Sequelae to injury that initially produced only an enamel fracture, A, but includes, in part B, pulpal necrosis, arrested root development, and apical periodontitis. Note crown discoloration in A, visible in transmitted light (arrow)

ed restorations. Placement of unsightly stainless steel or temporary acrylic crowns is now a thing of the past for enamel/dentin fractures.

Endodontic Considerations in Dental Trauma If the fractured crown fragment is available, it is often advantageous to use it to restore the tooth. The technique for reattachment (Figure 15-7) is as follows25–27: Anesthetize the tooth and place a rubber dam to isolate the tooth. Clean the tooth segment and fractured tooth with pumice and water. Determine the reattachment path of insertion, using a sticky wax handle to hold the coronal fragment. Care should be taken to accurately refit the fragment since it can easily be misaligned anteroposteriorly. Apply a suitable etchant, according to its manufacturer’s directions, to both the tooth and the coronal segment extending 2 mm beyond the cavosurface margins. Rinse well. Apply a dentinal primer followed by application of an unfilled resin. Next, dilute a light-cured composite resin with unfilled resin to a creamy consistency and apply it to the tooth

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and coronal fragment. Carefully re-insert the fragment onto the tooth, taking care that the path of insertion is correct. Remove excess resin and apply the curing light circumferentially. (Alternatively, a dual-cure resin luting agent may be used.) Polish the resin and check the orclusion, which can be adjusted if necessary. The expected outcome is usually good, although resistance to refracture is about 50% less than an intact tooth’s resistance.25 Early treatment of crown fractures is desirable. The length of time between injury and treatment has a direct adverse effect on the pulp’s ability to survive. The closeness of the fracture to the pulp and the size of the dentinal tubules also have a bearing on the pulp’s continued vitality, the latter being significant in young patients.1,22

Figure 15-7 A, Uncomplicated fracture, central incisor. The dentin has been temporarily covered with glass ionomer. B, Radiograph, showing fracture with incisal glass ionomer. C, The incisal tooth fragment, which had been kept in water for several days, has been bonded to the tooth after removal of the glass ionomer. D, The tooth as it appears 21⁄2 years after incisal fragment reattachment. (Courtesy of Dr. Mitsuhiro Tsukiboshi.)

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Follow-up and Prognosis. As with most traumatic injuries, patients with crown fractures need to be reevaluated periodically to determine pulpal status. Traumatized teeth can develop pulp necrosis some time after the initial injury, and if necrosis occurs, endodontic therapy is indicated.22 The prognosis is usually good for teeth with crown fractures in which the pulps are not exposed.1,22 The unpredictable part is determining the extent of concomitant pulp injury. Primary Teeth. Crown fractures are rare in the primary dentition, but when they occur, the pulps are exposed more often than in the permanent dentition. When the pulps are not exposed, treatment consists of smoothing rough edges or repairing with composite resin by the acid-etch technique.22 Crown Fractures—Complicated (With Pulp Exposure) Description. Crown fractures involving enamel, dentin, and pulp are called complicated crown fractures by Andreasen and Andreasen22 and Class 3 fractures by Ellis and Davey.23 The degree of pulp involvement varies from a pinpoint exposure to a total unroofing of the coronal pulp. The exposure of the pulp in complicated crown fractures makes the treatment more difficult. Bacterial contamination of the pulp precludes healing and repair unless the exposure can be covered to prevent further contamination. The initial reaction is hemorrhage at the site of the pulp wound. Next, a superficial inflammatory response occurs, followed by either a destructive (necrotic) or proliferative (“pulp polyp”) reaction.28 Incidence. It is fortunate, considering the treatment complications, that crown fractures exposing the pulps are far less common than those not involving the pulp. The incidence, compared with all types of dental injuries, ranges from 2 to 13%.22 Diagnosis. The diagnosis of crown fracture with pulp involvement can be made by clinical observation. In addition, it is important to determine the condition of the pulp. If the tooth has been luxated in addition to the crown fracture, pulpal recovery is compromised, and the longer the pulp is exposed before being protected, the poorer the prognosis for pulpal survival.22 Treatment. Traditionally, these injuries have often resulted in automatic pulp extirpation, even in young, developing teeth. Such drastic measures are not always necessary; vital pulp therapy preserves the potential for continued root development—an important consideration in a tooth with a thin, weak root structure owing to a lack of complete tooth development.

Treatment planning is influenced by tooth maturity and extent of fracture. Every effort must be made to preserve pulps in immature teeth. Conversely, in mature teeth with extensive loss of tooth structure, pulp extirpation and root canal therapy are prudent before post/core and crown restoration. Pulp preservation by vital pulp therapy includes pulp capping and pulpotomy. Both procedures permit preservation of pulp tissue for continued root development. Pulp capping is a time-honored procedure that is sometimes quite successful. However, in recent years, a modified pulpotomy technique (“Cvek type”)29 has shown itself to be more predictable. This pulpotomy technique may be termed “shallow pulpotomy” in contrast to the older method of removing coronal pulp tissue deeply to the cervical, or deeper, level. The “deep pulpotomy” techniques were difficult technically and failed to deliver what vital pulp therapy should: preservation of pulp tissue in the critical cervical area of the tooth, where subsequent fractures can occur in thin, weak walls of pulpless teeth. The procedure for shallow pulpotomy (also referred to as a partial or “Cvek-type” pulpotomy) can be performed by any well-trained dentist30,31 (Figures 15-8 and 15-9). After anesthesia and rubber dam isolation, remove granulation tissue from the exposure site using a spoon excavator. This permits evaluation of the size of exposure. Next, with a water-cooled, round diamond stone, remove pulp tissue from the pulp proper, to a depth of 1 to 2 mm. Visualize the removal, layer by layer, rather than a quick cut with the stone. Allow plenty of coolant water spray to irrigate and prevent heat damage to the subjacent pulp tissue. After preparing the pulp tissue, rinse the wound with saline and allow the bleeding to stop (a cotton pellet moistened with saline can be used to control the bleeding), then wash the wound gently with saline, and it is ready for coverage with a calcium hydroxide material. Apply the calcium hydroxide over the wound and also cover all exposed adjacent dentin. A hard-setting calcium hydroxide such as Dycal (Dentsply/Caulk, Tulsa, Okla.) is easy to use. Next, an intermediate base of hard-setting zinc phosphate cement or glass ionomer cement is placed before restoring with dentin adhesive and composite resin. After radiographic evidence of mineralization of the exposed pulpal area, it is recommended that the initial filling and liner be replaced to prevent microleakage. This may occur 6 to 12 months after the initial treatment.29,30 An alternative to the use of calcium hydroxide is a new material, mineral trioxide aggregate (MTA)

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Figure 15-8 Shallow pulpotomy. A, Crown fracture exposes pulp. B, Remove pulp tissue with a round diamond bur to a depth of about 2 mm; use water spray to cool the diamond. C, After bleeding has stopped, wash the pulp wound with saline and apply a calcium hydroxide liner on top of which a base must be placed. The base can be glass ionomer cement. D, The lost tooth structure is replaced with acidetched composite resin.

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A B

C D

Figure 15-9 A, Crown fracture exposing pulp. B, Patientâ&#x20AC;&#x2122;s age (10 years) and stage of root development (open apex) indicate need for perserving radicular pulp. C and D, Pulpotomy and calcium hydroxide to cervical level. E, Acid-etched composite restoration. (Restoration by Dr. James Dunn.) F, Radiograph taken years after accident. Note continued root development (arrow).

Endodontic Considerations in Dental Trauma (ProRoot MTA, Tulsa Dental/Dentsply, Tulsa, Okla.), which has found many uses in endodontics.32 It has been shown to be very effective in vital pulp therapy33â&#x20AC;&#x201C;36 (Figure 15-10). The technique for managing a traumatic pulp exposure using MTA is in many ways similar to that used with calcium hydroxide, with some minor modifications: 1. The tooth must be anesthetized and should be isolated with a rubber dam. 2. The tooth, fractured surface, and wound area should be disinfected using a solution such as sodium hypochlorite. 3. A shallow pulpotomy is done to provide space for the MTA. A round diamond stone is used in a highspeed handpiece with water irrigation to remove exposed pulp tissue to a depth of at least 2 mm into

the pulp proper. Bleeding is allowed to stop (which usually takes 2 to 3 minutes) before MTA is placed directly into the pulp wound. The presence of a small amount of blood in the wound area is not a contraindication to placing MTA; in fact, some moisture is required for the proper curing of the material. 4. Since access is not a problem when performing a shallow pulpotomy, the placement of MTA is not as difficult as it often can be when used for other purposes, such as repair of perforations. The mixture of MTA powder and liquid should be of such a consistency that it can be carried from the mixing pad to the pulp wound using a dental instrument such as a spoon excavator. A small amount of MTA should be placed on the wound surface and gently tapped with a moist cotton pellet so that it covers the exposed

Figure 15-10 A, Complicated crown fractures with pulp exposure in both central incisors. B, Radiograph shows immature, developing roots with wide open apices. Shallow pulpotomy was done on both teeth, using mineral trioxide aggregate to protect the underlying pulp. C, Radiograph taken 2 years later shows excellent continued root formation in both teeth. D, Three years after vital pulp therapy.

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pulp. Next, the entire access into the pulp should be filled in a similar manner using small amounts of MTA. Any excess moisture should be removed from the surface of the MTA using a dry cotton pellet. 5. The rubber dam can then be removed, and the patient can be dismissed. Leaving the MTA exposed to saliva will allow it to cure. A minimum of 6 hours should be allowed for the material to adequately cure, but clinical experience indicates that waiting at least 24 hours is better. The tooth can then be restored with a definitive restoration. Previous research34,35 has shown that the pulp responds favorably to the protection provided by an MTA layer. The reparative dentin is consistently more uniform and thicker under MTA compared with calcium hydroxide. As has been convincingly demonstrated,37 the pulp can tolerate almost any dental material and produce new dentin as long as it can be protected against microleakage, a function that MTA appears to perform better than any material with which it has been compared. The differences in the vital pulp therapy technique when MTA is used in place of calcium hydroxide are important to consider. First, it is not important that the pulp wound bleeding be completely stopped prior to placing the MTA; in fact, the presence of a small amount of blood provides necessary moisture for curing of the material and has been shown to work as well as any other fluid.38 Second, since the MTA needs to cure prior to placement of a definitive restoration, it is necessary to schedule two appointments for this procedure: the first to perform the shallow pulpotomy and place the MTA on the pulp wound and the second to complete the restoration after the material has cured. Future material development may be expected to result in a faster-curing MTA. Third, it is not necessary to reenter the pulpotomy site later to remove the pulp capping material, as has been recommended for calcium hydroxide pulpotomies.29,30 Mineral trioxide aggregate does not appear to deteriorate and disintegrate with time; thus, space for microleakage does not develop as it does with calcium hydroxide. In mature, fully developed teeth, particularly those treatment planned for full-crown coverage, conventional root canal therapy is the treatment of choice. It should be pointed out that shallow pulpotomies can be performed in mature teeth, thus preserving pulp tissue and accomplishing repair quite conservatively. But it should probably be reserved for instances of crown fractures in which the fractured segment can be restored with composite resin or when rebonding of the fractures segment is possible.

With respect to the length of time pulp tissue can be exposed and still permit vital pulp therapy to be performed, studies by Heide28 and Cvek29 indicate that it may be safe to proceed with shallow pulpotomies up to 1 week post fracture. After that, it is probably questionable in mature, fully formed teeth, although in young, developing teeth with wide-open apices, it is worth attempting to save pulps even when they have been exposed for more than a week. The goal is to promote continued root formation. Follow-up and Prognosis. A number of studies have evaluated the prognosis of traumatized anterior teeth, including those with crown fractures.39â&#x20AC;&#x201C;43 The teeth need periodic evaluation, radiographically and clinically, to determine pulpal status. Discoloration associated with the interphase between tooth structure and bonded resin material may indicate microleakage, and the restoration should be replaced to prevent bacterial contamination of the exposure site. Acceptable results of evaluation following pulpotomy should be all of the following42: 1. 2. 3. 4.

No clinical signs or symptoms No evidence of periradicular pathologic changes No evidence of resorption, either internal or external Evidence of continued root formation in developing teeth

Evidence of root canal obliteration by calcified tissue is often taken as a sign of pulp degeneration. Lumen reduction can be seen years after trauma and treatment,44,45 but such calcification is not necessarily an indication of pulp necrosis.45 The decision to intervene endodontically in cases of apparent pulp space calcification should be based on evidence of pulp necrosis and not on pulp calcification. If root canal treatment has been performed, either immediately after the injury or subsequent to pulp capping or pulpotomy, follow-up evaluation of healing should be done, particularly if luxation of the tooth occurred, to monitor for possible root resorption.1 Primary Teeth. Crown fractures involving the pulp are not common in the primary dentition.46 When such injuries occur, pulpotomies or pulpectomies may be considered. Pulp capping is generally not successful in primary teeth, and endodontic treatment is difficult owing to the tortuous and fine canal structure. Patient management is a further complicating factor in treating fractured primary teeth. The result of poor cooperation is often tooth extraction.47 Pulpotomy is indicated when the pulp is still healthy and pulpectomy when the pulp is not expected to

Endodontic Considerations in Dental Trauma recover. The procedures are the same as described above for the permanent dentition, except that the root canal filling material should be a resorbable cement such as zinc oxideâ&#x20AC;&#x201C;eugenol. For additional details, see chapter 17. Crown-Root Fractures In these fractures, enamel, dentin, and cementum are involved. If the pulp is also involved, the case is considered more complicated. Description. Crown-root fractures in anterior teeth are usually caused by direct trauma.48 This may result in a chisel-type fracture, with the apical extent of the fracture below the lingual gingiva (Figure 15-11). These fragments may be single or multiple, leaving the fragment or fragments loose and attached only by periodontal ligament fibers (Figure 15-12). The pulp may also be involved, depending on the depth of fracture into the dentin, further complicating a difficult traumatic injury. In posterior teeth, the causes of crown-root fractures have been attributed to indirect trauma including large-size restorations, thermal cycling, high-speed instrumentation, pin placement, and direct trauma, such as accidental blows to the face and jaws. The role of restorative procedures is not well understood, particularly in regard to occlusal restoration size and resultant fractures.49 As in anterior teeth, two types of crown-root fractures are recognized in posterior teeth: those with and those without pulpal involvement.

809

The vertical fracture of endodontically treated teeth is an additional type of crown-root fracture involving both anterior and posterior teeth (Figure 15-13). Most appear to be caused by the endodontic treatment itself or by subsequent inlay or dowel placement49 (see Chapters 13 and 19). Incidence. Crown-root fractures per se are not generally recognized as a separate entity, and little information is available about their frequency of occurrence. Andreasen and Andreasen reported a 5% incidence of total dental injuries.48 However, when one includes the so-called cracked tooth syndrome and vertical fractures of endodontically treated teeth (all are caused by trauma in one form or another), the total incidence may be higher. For additional information, see chapter 13. Diagnosis. Crown-root fractures result in complaints of pain, particularly when the loose fragment or fragments are manipulated. The fragments are generally easy to move, and bleeding from the periodontal ligament or pulp often fills the fracture line. Because of the mobile parts, percussion is seldom useful in determining apical periodontal involvement. However, that may be done later, after removal of the loose fragments. Unless the pulp is exposed, EPT should be performed on the injured and adjacent teeth. Radiographs of anterior crown-root fractures are often difficult to interpret. It is very important to take more than one angulation to assess the extent of fractures. Angulations of films should include both additional horizontal and vertical angulations.

Figure 15-11 A, Crown-root fracture of the â&#x20AC;&#x153;chisel typeâ&#x20AC;? extending below the alveolar crest palatally. B, Such teeth may be orthodontically extruded for restorative reasons.

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E Figure 5-12 Crown-root fracture with pulp exposure. A, Note loose mesial crown fragments, which are attached by periodontal ligament fibers. B, After anesthesia, loose fragments are removed and rubber dam applied. Note exposure of radicular pulp (arrow). C, The remainder of coronal pulp tissue is amputated and the surface of pulp allowed to coagulate. Cotton pellet (CP) aids by controlling initial bleeding. D, After surface coagulation, the area is irrigated and calcium hydroxide placed directly over pulp tissue. It helps to prepare a shelf around the pulp orifice to support the base and prevent the cement from being pushed into the underlying pulp tissue (arrows point to shelf in dentin). E, After placement of base, acid-etched composite will be used for final restoration.

Endodontic Considerations in Dental Trauma

811

A Figure 15-13 Vertical root fracture of an endodontically treated tooth. A, Radiograph shows characteristic “drooping” lesion (arrows) around the root of a premolar with a very large diameter but short post. B, Photograph shows vertical fracture of the root (black arrow).

Posterior crown-root fractures may be very difficult to diagnose because they are more inconspicuous. The examination and diagnosis of cracked tooth syndrome are discussed in chapters 6 and 7. Treatment. There are several treatment options available for crown-root fractures, depending on the extent of the fracture.1 If the fragment can be reattached by bonding, and no pulp exposure has occurred, that is the most conservative and convenient approach. If pulp exposure has resulted from the fracture (see Figure 15-12), either a shallow pulpotomy procedure (if the tooth is still developing) or root canal treatment (fully developed teeth) must be done prior to any rebonding or crown restoration.50 Crown-root fractures extending well below the alveolar crest may require surgical repositioning of the tissues to expose the level of fracture. Long-term esthetic problems may, however, result from such surgical procedures.1 Extrusion—either surgical51 or orthodontic52—can also be done to allow better restoration of the fractured tooth. See Figures 15-14 and 15-15 for illustrations of orthodontic extrusion. Prognosis and Follow-up. The quality of the restorative procedure is an important factor in determining the long-term success of treating crown-root fractures. Both the loss of significant tooth structure and often the difficulty in restoring normal crown contour contribute to a guarded prognosis.

If the pulp is not initially involved, its continued vitality depends on one’s ability to protect it from contamination. If possible, the condition of the pulp should be evaluated for a sufficient period of time to detect necrosis should it occur. Primary Teeth. Fractures involving crowns and roots of primary teeth occur infrequently, and when they do, extraction is indicated.48 Root Fractures This type of fracture involves the roots only: cementum, dentin, and pulp (Figure 15-16). Incidence and Description. Intra-alveolar root fractures do not occur frequently compared with other dental injuries and account for probably less than 3% of all dental trauma. These fractures are generally transverse to oblique and may be single or multiple, complete or incomplete.53 Incompletely formed roots rarely fracture, but when they do, the prognosis is usually very good.54 Diagnosis. Root fractures are not always horizontal; in fact, probably more often than not, the angulation of fractures is diagonal (Figure 15-17). This fact probably explains why root fractures are often missed radiographically. With the conventional 90-degreeangulation periradicular x-ray film, if the fracture is diagonal, it is very likely that it will be missed. Only when the x-ray beam can pass directly through the fracture line does it show on the radiograph. It is there-

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Endodontics

Figure 15-14 Basic technique for root extrusion. A, Root fracture at or below crestal bone. B, Root canal therapy completed. C, Cementation of a post-hook. D, Occlusal view; horizontal wire is bent to cross midline of the tooth to be extruded. Wire is embedded with acid-etched composite on adjacent teeth. E, Elastic is attached to activate extrusion. F, When satisfactory extrusion has been completed, the tooth is stabilized until periodontal and bony repair are complete. G, Periodontal and bony repair completed. H, Permanent restoration. (See also Figure 15-15.)

fore imperative to take additional film angulations when root fracture is suspected.53 One additional film angulation (foreshortened or 45 degrees) will, when combined with the standard 90degree positioning, reveal most of the traumatic root fractures.55 Treatment. If there is no mobility and the tooth is symptomless, the fracture is likely to be in the apical one-third of the root, and no treatment is necessary

(Figure 15-18). If the coronal fragment is mobile, treatment is indicated. The initial treatment consists of repositioning the coronal segment (if it is displaced) and then stabilizing the tooth to allow healing of the periodontal ligament supporting the coronal segment53 (Figure 15-19). Repositioning can be as simple as pushing the tooth into place with finger pressure, or orthodontic intervention may be required to move the displaced segment

Endodontic Considerations in Dental Trauma

813

Figure 15-15 A, Crown-root fracture of a right central incisor necessitating orthodontic extrusion owing to palatal extension of fracture. Note that the loose palatal segment (arrow) is still present. B, Adequate remaining tooth length allows use of the technique. C, One-visit root canal therapy performed after removal of loose palatal fragement. D and E, Extrusion hook cemented in prepared post space.

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Figure 15-15 (Continued) F, Horizontal wire attached to adjacent teeth at desired position by acid-etched composite. G, Activation elastic placed over hook and wire. H, Two weeks later, the tooth has extruded the desired distance. I, It is now stabilized for 8 weeks by use of ligature wire.

Endodontic Considerations in Dental Trauma

L Figure 15-15 (Continued) J, Note apical radiolucency (arrows) immediately following extrusion and K, recalcification after 8 weeks of stabilization. L, Palatal tissue shows good adaptation to crown (arrows). As a result of extrusion, gingival bevel could be placed on newly exposed tooth structure.

815

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Endodontics

Figure 15-16 A, Root fractures involve cementum, dentin, and pulp and may occur in any part of the root: apical, middle, or coronal thirds. B, Fractures may also be comminuted (arrows).

Figure 15-17 A, Graphic illustration showing two angulations (90 and 45 degrees) to better detect root fractures. B, Photograph showing a root fracture (arrow) that could not be detected with a 90-degree angulation C, By changing the angulation to a more foreshortened view (approximately 45 degrees). D, The fracture is easily demonstrated (arrow).

Figure 15-18 Root fracture (arrow) healed spontaneously. The patient was unaware of the fracture.

Endodontic Considerations in Dental Trauma

Figure 15-19 Root fracture. A, Immediately after the accident. Note displacement of the coronal segment (arrows). B, The coronal segment has been repositioned and the splint has been attached to stabilize the fractured tooth. C, Radiograph taken just before removal of the splint. D, Control radiograph taken 1 year after removal of the splint. The tooth is comfortable and responds to the electric pulp test within normal limits. There is no abnormal mobility or discoloration of the tooth. (Courtesy of Dr. Donald Peters.)

817

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Endodontics

into proper alignment. Generally, if considerable time has elapsed between the injury and the treatment appointment, it is more difficult to reposition the coronal segment in line with the apical segment (â&#x20AC;&#x153;reducing the fractureâ&#x20AC;?). Splinting is best accomplished by incorporating a thin orthodontic wire into labially bonded composite resin. The splint should allow for functional movement of the tooth to promote healing, and the length of stabilization time is 4 to 6 weeks.56 Following initial treatment by reduction and stabilization, repair by calcific and/or fibrous deposition is very likely. About 80% of properly treated root fractures heal successfully. The prognosis is related to the amount of dislocation, stage of root development, and probably whether treatment was done. Fracture location apparently matters less as long as it is not too close to the alveolar crest.57 The amount of dislocation and the degree of mobility of the coronal segment affect the prognosis because the more severe the dislocation (and therefore the mobility), the less likely it is that fracture reduction can be accomplished, and also the more likely it is that the pulp has been severely injured.58 The stage of root development matters in root fractures because, with other dental injuries, the more immature the tooth, the better the ability of the pulp to recover from trauma. The rich vascular supply to a young, immature tooth promotes repair.59 The conventional wisdom of dentists for years was that root fractures occurring in the coronal half had a poorer prognosis than those taking place more apically. In the important study by Zachrisson and Jacobsen on root fracture outcome, it was surprising to see that location did not influence outcome.58 Apparently, then, if a tooth can be stabilized long enough for repair to occur, the location of the fracture is immaterial. The only exception naturally would be fractures that occur so close to the crest of the alveolar bone that the support of the tooth is compromised. Also, if communication develops between gingival sulcus and the fracture site, the prognosis has to be considered poor. Sequelae to root fractures may be divided into four types, as proposed by Andreasen and HjĂśrting-Hansen60: 1. Healing with calcified tissue. Radiographically, the fracture line is discernible, but the fragments are in close contact (see Figure 15-19, D). 2. Healing with interproximal connective tissue. Radiographically, the fragments appear separated by a narrow radiolucent line, and the fractured edges appear rounded (Figure 15-20).

Figure 15-20 A, Root fracture in which healing resulted in connective tissue between the segments. B, Note that the segments appear to be separated by narrow radiolucent lines (arrows) and the rounding effect of the fractured edges.

3. Healing with interproximal bone and connective tissue. Radiographically, the fragments are separated by a distinct bony bridge (Figure 15-21). 4. Interproximal inflammatory tissue without healing. Radiographically, a widening of the fracture line and/or a developing radiolucency corresponding to the fracture line become apparent (Figure 15-22). The first three types are considered successfully healed injuries; they are asymptomatic, probably respond to electric vitality tests, and may, over time, show only signs of coronal discoloration (yellowing) owing to coronal calcification.57,58 Fractures that do not heal need additional endodontic treatment. Failing root fractures have characteristic lesions that develop adjacent to the fracture sites, not apically, as in most teeth with necrotic pulps.60 Further, there is good reason to expect the apical segment of the root-fractured tooth to contain vital, healthy pulp tissue, whereas the coronal pulp is necrotic. The treatment options are therefore many: 1. Root canal therapy of both segments. This may be indicated in fracture cases when the segments are not separated, allowing passage of files and filling materials from the coronal segment across the fracture site into the apical segment (Figure 15-23). 2. Root canal treatment of the coronal segment only (Figure 15-24). This is the current recommendation, particularly with the view that the apical segment may contain vital, healthy pulp tissue.54 A variation to this approach has been recommended by Cvek.61 He used an apexification procedure in the coronal

Endodontic Considerations in Dental Trauma

819

Figures 15-21 A, Healing by interproximal bone. B, Root fracture (arrow) resulting in total separation of fragments. C, Midroot facture stabilized for 3 months. D, Note that after removing the splint, the incisal edges are even, yet a space is apparent between the segments. E, Eight months later, bone is now apparent between segments. F, The interproximal space has enlarged further 2 years after the accident. The tooth is firm and functional. Note calcification of the pulp space. (Courtesy of Dr. Milton Siskin.)

segment, inducing a hard tissue barrier at the exit of the coronal root canal. Although there are no studies at the present time reporting on the use of MTA in root fractures, it would be reasonable to expect that this material could be used instead of calcium hydroxide in root fractures.9 3. The use of an intraradicular splint has been recommended by Weine et al.62 It is similar to the first procedure described; both segments are treated endodontically. Following root canal filling, a post space is prepared in the canal to extend from the coronal segment into the apical one, allowing placement of a rigid-type post (cobalt-chromium alloy [vitallium]) to stabilize the two root segments. 4. Root extrusion is a solution for teeth with root fractures at or near the alveolar crest.52 This treatment plan must be evaluated carefully because the length of root left after the extrusion must be enough to

Figure 15-22 A, Root fracture resulting in interproximal inflammatory tissure. B, Large periradicular lesion (small arrows) adjacent to fracture line (white arrow).

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Endodontics

Figure 15-23 Root fracture treated by root canal therapy of both apical and coronal fragments. A, Note the fistulous tract. B, Tract traced with a gutta-percha point to the root fracture (white arrow). Periodontal lesion associated with fracture is evident (dark arrows). C, Segments aligned properly so that instrumentation is possible. D, Sealer extruded into the interproximal area (arrows). E, Follow-up at 11 months shows resolution of the lesion with a small remaining area expected to heal.

support a new crown. A reasonable guide is to consider a crown-root ratio of 1:1 to have adequate support. See Figures 15-14 and 15-15 for extrusion technique. Follow-up and Prognosis. It is a commonly held opinion that teeth with root fractures have a poor prognosis, particularly if the fracture is in the middle or coronal third. Whereas it may be true that the prognosis is poor for longitudinal fractures, it appears unfounded for transverse fractures56 (see Figure 15-19). A slight discoloration of the crown is a frequent observation in healed root-fractured teeth, usually seen as a yellowing effect with reduced transparency.63 It is associated with pulp obliteration and occasionally a

loss of response to the EPT. Endodontic treatment is not indicated unless other evidence, such as root resorption or periradicular radiolucencies, indicates pulp necrosis. Usually, if the pulp space becomes obliterated, no radiolucencies are seen apically or associated with the fracture lines. Endodontic treatment then becomes a decision based on other factors pertinent to each individual case.57 Teeth requiring endodontic treatment after root fractures also have a good prognosis with proper treatment unless the fracture is so close to the alveolar ridge that it communicates with the gingival crevice.57,58 In the latter case, removing the coronal fragment and extruding the root orthodontically may be the treatment of choice.52

Endodontic Considerations in Dental Trauma

821

Figure 15-24 A, Radiograph shows a central incisor with an apical root fracture and a crown fracture repaired with composite resin 7 years earlier. The pulp had not survived the original injury, and the patient had an apical abscess. Note the separated apical root segment. B, Radiograph taken 4 months after initial treatment: root canal cleaning and calcium hydroxide medications. C, The tooth immediately after root canal filling. Note that the apical lesion responded favorably to the initial endodontic therapy and the apical root fragment is not involved. D, Twelve months after filling the root canal, the radiograph shows good repair; the apical root fragment can be left in place.

Long-term follow-up with radiographs and clinical tests is indicated in root fractures cases, as with all other types of dental injury. It would appear that few root-fractured teeth need to be extracted. With proper treatment, even those with coronal-third involvement can be expected to survive, although some will require endodontic and possibly orthodontic intervention. Primary Teeth. Root fractures are infrequent in primary teeth. When they occur, however, the coronal fragment should be extracted. If the removal of the apical segment requires much manipulation, it may be left in its socket. It will resorb during the growth and emer-

gence of the succedaneous tooth. Excessive manipulation may damage the permanent tooth bud.53 Luxation Injuries This category of dental injuries includes impact trauma that ranges from minor crushing of the periodontal ligament and the neurovascular supply to the pulp to more major trauma such as forceful and sometimes total displacement of teeth (avulsion). Injury to a toothâ&#x20AC;&#x2122;s supporting structure seldom spares the pulp from trauma. Only in cases of minimal trauma does the pulp have a good chance of recover-

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Endodontics

ing. Otherwise, when a tooth is impacted by a blow, the force is very likely to damage the vasculature entering the apical canal opening, with the result that the pulpal blood supply is compromised64,65 (see chapter 4). Besides pulpal injuries, impact trauma may also affect the tooth’s periodontal support. Loss of attachment, if not restored by subsequent repair, will result in pocket formation and reduction in tooth support. The goal in treatment of luxation injuries is to promote recovery of both pulpal and periodontal health; realistically, except in young, immature teeth, pulpal recovery is not as likely to occur as periodontal repair.66 Incidence. Tooth luxation (not including avulsion) is a frequent injury, comprising the largest group of injuries in the classification of dental trauma, ranging from 30 to 44%.66 These figures are probably on the low side since many instances of mild luxation, such as concussion, go unreported. In severe injuries, luxations may go unnoticed in the face of more obvious injuries. It is important, though, to record findings indicating luxations, even mild ones, because of the high rate of subsequent pulp necrosis, osteitis or apical periodontitis, and root resorption associated with such injuries. Following extrusion-luxation, Dumsha and Hovland reported pulp necrosis in 51 of 52 teeth after a period that ranged from 4 weeks to 18 months.67 A frequently overlooked cause of luxation injuries, including avulsions, occurs during intubation in the operating room. Damaged teeth were the most frequent anesthesia-related insurance claim during the time period 1976 to 1983.68 Diagnosis. Luxated teeth that have been loosened or slightly displaced are sensitive to biting and chewing. In concussion, this may be the only symptom, and it is noted by percussing the tooth. In more severe injuries, such as subluxation and extrusive luxation, signs and symptoms in addition to percussion sensitivity may be present: sensitivity to pressure and palpation of the alveolus, mobility, dislocation, and possibly bleeding from the periodontal ligament. Radiographs do not always reveal the extent of injuries to the supporting structures but are important nonetheless; it is also important to include additional radiographic angulations. Discoloration of the crown may also be noted and, if present shortly after the injury, is indicative of severe pulp damage. Lateral and intrusive luxations are usually firmly displaced and may not be sensitive to percussion.66 Electric pulp testing should be carried out and recorded in cases of luxation, in spite of the fact that an initial “no response” is common. The results of the EPT provide the basis for later evaluation. It is generally found that teeth with an initial normal response but a

negative response later have developed either pulp necrosis or calcification. However, without other indications of pulp necrosis, endodontic intervention should not be based solely on a negative response. Treatment. Initial treatment can be as simple as doing nothing while the patient avoids use of the tooth. In more serious luxations, treatment may range from slight occlusal adjustment to repositioning (reduction) and splinting (stabilization) for 2 to 6 weeks. If symptoms and other conditions (crown fracture with pulp exposure) indicate irreversible pulp involvement, endodontic treatment is indicated immediately after injury. Follow-up evaluation will determine possible later need for root canal therapy.69–73 Concussion This is the mildest form of luxation injury, and it is characterized by sensitivity to percussion only. No displacement has taken place, and there is no mobility as a result of the injury. Concussion is probably present in most cases of crown, root, and crown-root fractures.66 Treatment for concussion is symptomatic: allow the tooth to rest as much as possible to promote recovery of trauma to periodontal ligament and apical vessels. Monitor pulpal status by EPT and watch clinically for tooth color changes and radiographically for evidence of resorption. The prognosis is good.66 Subluxation When a tooth, as a result of trauma, is sensitive to percussion and has increased mobility, it is classified as subluxated. Electric pulp test results may be either no response or positive; if they are the former, damage to the apical neurovascular bundle is more severe, and pulpal recovery becomes questionable, except in developing teeth.69–73 Treatment initially may be none, except to recommend minimal use, or it may be necessary to stabilize the tooth for a short period of time (2 to 3 weeks) to promote periodontal ligament recovery and reduction in mobility1 (Figure 15-25). Subluxated teeth need to be evaluated long enough to be certain that the pulps have fully recovered. It may take 2 or more years before one can make such a final determination. Pulps that do not recover sensitivity to EPT should be assumed to be necrotic even if they are asymptomatic. Definitive treatment for subluxated teeth often includes root canal therapy for fully developed teeth.71 Extrusive Luxation Displacement of a tooth axially in a coronal direction results in a partial avulsion. The tooth is highly mobile

Endodontic Considerations in Dental Trauma

823

Figure 15-25 Examples of two types of functional splints. A, Unfilled resin is bonded to small, etched labial areas. Avoid etching interproximally. B, A thin (0.3 mm) orthodontic wire can be bonded to small, etched labial areas with resin.

and is likely to be continually traumatized by contact with opposing teeth, owing to the premature occlusal condition, all of it contributing to patient discomfort and severe tooth mobility66 (Figure 15-26). Immediate urgent care consists of repositioning the tooth, usually more easily accomplished than in lateral luxation, and stabilizing it by a functional splint for 4 to 8 weeks (see Figure 15-25). The relatively long stabilization period is to allow realignment of the periodontal ligament fibers supporting the tooth. It is important during this period that gingivitis be prevented. Gingival inflammation will negate any attempt of the tissue to repair itself. During recovery, progress can be monitored by periodontal probing. When reattachment has occurred, probing depth should be similar to pretrauma depth.1,66 Definitive treatment for extrusive luxation is likely to include root canal therapy,71 except in young, developing teeth in which the pulps are more prone to recover.69 It is important to watch for signs of root resorption if endodontic therapy, for any reason, is not included in the early treatment plan. Root canal therapy should be performed if the pulpal condition at any time is judged to be either irreversible pulpitis or pulp necrosis. It should be done without delay once the decision to do so has been made to reduce the chances of inflammatory root resorption.1,67 Lateral Luxation Traumatic injuries may result in displacement of a tooth labially, lingually, distally, or mesially (Figure 15-27).

Such displacement is called lateral luxation, and it is often very painful, particularly when the displacement results in the tooth being moved into a position of premature occlusion. An example of such lateral luxation is when a maxillary incisor is pushed palatally. The crown makes occlusal contact long before centric occlusion. The tooth is painful from the injury alone, and the additional constant trauma of premature contact results in severe pain. Initial, urgent care for lateral luxation cases includes repositioning the tooth and stabilization if the tooth is mobile after being repositioned. Repositioning a laterally luxated tooth may require pressure application at the apical end of the root in the direction of the root apexâ&#x20AC;&#x2122;s original location or by partially extracting the tooth with forceps prior to repositioning. The splinting, if needed, should be nonrigid and may need to be in place for 3 to 4 weeks, depending on how soon the supporting tissues recover.1,66 Definitive treatment for laterally luxated teeth includes root canal therapy (Figure 15-27, D), except in developing teeth, which may revascularize.69,70 The tooth displacement has probably severed the blood vessels supplying the pulp, resulting in an infarct of the pulp owing to hypoxia. The end result is coagulation necrosis, which, even if asymptomatic, requires root canal therapy. If a decision to delay endodontic treatment is made, it is imperative to monitor the tooth radiographically for possible external, inflammatory root resorption. The prognosis for lateral luxation is good if proper endodontic therapy is performed when indicated.66

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Endodontics

C Figure 15-26 A, Tooth extrusion is similar to luxation in that the tooth is displaced, but the direction is axial. It may be accompanied by fracture of the alveolus. B, Note outline of root socket at apex (arrow). C, Bleeding is frequently seen from the gingival sulcus (arrows).

Intrusive Luxation A tooth may be pushed into its socket, resulting in a very firm, almost ankylosed tooth (Figure 15-28). Such intrusive luxations require diverse treatment approaches depending on the stage of tooth development: little or no treatment for very immature teeth, aggressive initial treatment for more mature teeth.1,66

In cases of intrusive luxation of developing, immature teeth, the theory behind not doing anything initially is based on the expectation that a tooth with a wide open apex has the potential to re-erupt spontaneously and establish a normal occlusal alignment within a few weeks or months74 (Figure 15-29). Monitor the progress of re-eruption, and if the tooth

Endodontic Considerations in Dental Trauma

825

Figure 15-27 A, Tooth luxation with loosening and displacement is often accompanied by fracture or comminution of the alveolar socket. B, Luxation displacement of left central and lateral incisor and canine (arrows). C, After repositioning. D, The incisor required root canal therapy about 3 months later. Canine retained its pulp vitality. (Courtesy of Dr. Raleigh Cummings.)

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Endodontics

Figure 15-28 A, Graphic illustration of a tooth intruded into the alveolar bone. B, Clinical photograph of intruded incisor. Note bleeding from injured labial gingiva.

does in fact erupt into the normal position, no other treatment is needed. Radiographic control will probably show some bizarre pulpal calcification, but, lacking other evidence of pulpal deterioration, root canal therapy is not likely to be indicated. Fully developed teeth, however, and those in which the roots are close to being developed should be repositioned either surgically or orthodontically or by a combination of both.1 If allowed to remain in an intruded position, the tooth is very likely to become ankylosed, and later attempts at extrusion will probably be unsuccessful. The pulp should be prophylactically extirpated as soon as feasible, followed by completion of the root canal treatment after healing of the periodontal ligament

(Figure 15-30). The exception to endodontic treatment is when spontaneous eruption takes place in young, developing teeth1,66 (see Figure 15-29). Prognosis and Follow-up Evaluation. Complications following luxation injuries are frequent. Pulp necrosis occurs in over half of the cases of lateral luxation, and even in subluxations, pulp death occurs in 12 to 20% of cases.66 Extension of pulp necrosis to the periradicular tissues may take some time. Often apical periodontitis is not detected for several years post trauma, emphasizing the absolute need for long-term follow-up.71 Other complications are crown discoloration and reduction of the pulp lumen by calcification (Figure

Figure 15-29 A, Intruded immature tooth (arrow). B, Six weeks later. Note re-eruption of the left central incisor, almost catching up with its contralateral mate.

Endodontic Considerations in Dental Trauma

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Figure 15-30 Maxillary central incisors were intruded; the crowns fractured also. A, The intruded teeth were orthodontically extruded and the pulps were extirpated, followed by placement of calcium hydroxide in the canals. B, Radiographs taken after extrusion was accomplished and the root canals were filled. The entire procedure took place over a 2-year period. No evidence of ankylosis is present. (Courtesy of Dr. Arthur LeClaire.)

15-31). A yellow discoloration is indicative of pulp space calcification, whereas a gray color indicates pulp necrosis. Lumen obliteration, as observed radiographically, is a very common occurrence but does not always indicate pulp necrosis and does not alone indicate the need for endodontic therapy even if the pulp does not respond to EPT, as so often happens.64â&#x20AC;&#x201C;67,69,74 Resorption (external or internal) occurs in 5 to 15% of luxation injuries, usually within the first year and often within the first 2 to 5 months66 (Figures 15-32 and 15-33). The possibility of resorption shows the need for follow-up. During the first year after trauma, evaluation should be done after 4 to 6 weeks and after 6 months. After that, yearly recalls are indicated.71 Treatment for resorption is root canal therapy, which can arrest the resorptive process if it is inflammatory external or internal resorption.66,75 If root formation is incomplete at the time of trauma, its continuation may be interrupted if the pulp dies. This presents serious treatment problems. Apexification procedures will provide an apical stop for root canal filling (Figures 15-34 and 15-35), but the

Figure 15-31 Right central incisor had been intruded in an accident when the patient was about 6 years old. The tooth re-erupted, and many years later the tooth is functional, asymptomatic, and responds to electric pulp testing, but shows dystrophic radicular calcification.

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Endodontics

B Figure 15-32 External inflammatory resorption. A, Accidentally luxated tooth, radiograph taken 8 weeks after the incident. Note resorption of both dental hard tissues as well as adjacent alveolar bone. B, Immediately after root canal therapy. C, Control radiograph taken 12 months later. Note repair of the alveolus and establishment of a new periodontal ligament space. The root canal procedure arrested the resorptive process. (Courtsey of Dr. Romulo de Leon.)

A Figure 15-33

B A, Internal resorption with a history of trauma. B, Immediately following root canal therapy.

Endodontic Considerations in Dental Trauma

Figure 15-34 Graphic illustration of apexification procedure using calcium hydroxide to induce apical closure. A, Tooth with a necrotic pulp and an open, divergent apex. B, The thin root canal walls dictate that canal preparation be done very gently with minimal removal of dentin. The canal must be irrigated frequently. C, After careful cleansing of the canal, it can be filled with calcium hydroxide (a) to the level of vital tissue. Using a prepared calcium hydroxide paste deposited by a syringe and needle (b) combination facilitates the procedure. D, The needle is withdrawn as the material is deposited in the canal. E, During the treatment phase, the canal is filled with calcium hydroxide (a), on top of which is placed a cotton pellet (b), followed by a reinforced zinc oxide–eugenol paste or an acid-etched bonded resin. F, The goal is to induce an apical hard barrier (d).

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teeth are weak and prone to fractures (Figure 15-36). Cvek showed that, after 4 years, fractures ranged from 77% of the most immature teeth to 28% of the most fully developed teeth.75 Every effort should be made to promote revascularization of pulps in traumatized, developing teeth to allow continued root formation. It is possible that a reason for the high incidence of cervical root fractures in teeth that have undergone calcium hydroxide apexification—in addition to the thin root walls of developing teeth—may be an adverse effect of calcium hydroxide on dentin, in which the dentin becomes progressively more brittle as it continues to be in contact with calcium hydroxide.76 A better approach to apexification may be one in which a combination procedure is done (see Figure 15-36): 1. Use calcium hydroxide for a short period of time— about 2 weeks—to assist in disinfection of the root canal.77 2. Place MTA in the apical part of the canal to serve as an apical plug that promotes apical repair.78 3. After checking that the MTA has cured, complete the root canal treatment with gutta-percha and a bonded resin restoration extending below the cervical level of the tooth to strengthen the root’s resistance to fracture.79 Primary Teeth. Injury involving primary teeth results in damage to the supporting structures much more frequently than in crown or root fractures.80 The initial observation is often a grayish discoloration of the crown, which may change to a yellow color, indicating calcification (Figure 15-37). This is in contrast to permanent teeth, in which a grayish crown discoloration indicates pulp necrosis. In primary teeth, the most frequent sequela to trauma is pulp space obliteration by calcification, although internal and external resorption, apical lesions, and discoloration can occur.81 Since the primary crown changes color in most trauma cases, treatment, whether endodontic or exodontic, should be done only in the presence of other clinical or radiographic signs of pulp necrosis. Electric pulp testing of primary teeth is not practical, so one has to rely on other information, such as periradicular osteitis.81 If periradicular lesions develop, either endodontic or exodontic treatment is indicated. Although periradicular inflammation of short duration appears to have little or no effect on the succedaneous permanent tooth, lesions present for protracted periods of time do cause defects in the permanent successor82 (Figures 15-39 and 15-40).

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Endodontics

Figure 15-35 Induction of root-end closure with calcium hydroxide paste. A, Pulps of all four maxillary incisors have been devitalized by a traumatic accident. The apices are wide open. B, Seven months after filling with calcium hydroxide paste, the root apices have closed sufficiently to allow root canal filling. C, Root canals filled with gutta-percha. Total apical closure is shown by dense blunted fillings (arrow). (Courtesy of Dr. Alfred L. Frank.)

Figure 15-36 Fracture prone tooth. A, Owing to pulp necrosis in a developing tooth, apexification was begun with a good initial result; the apex was developing a hard tissue barrier. But the tooth is weak and prone to fracture cervically (arrow). B, The tooth did fracture as a result of a minor injury to the teeth.

Endodontic Considerations in Dental Trauma

Because little or no hard tissue barrier is present apical to primary teeth, traumatic intrusion of a primary tooth affects the odontogenesis and the eruption of the permanent tooth. On the other hand, the damage is usually minor, and the majority of intruded primary teeth re-erupt within 6 months. Treatment is only symptomatic, but follow-up evaluation is important. If evidence of apical inflammation becomes apparent, endodontic treatment or extraction is indicated to protect the permanent successor.82â&#x20AC;&#x201C;84

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Figure 15-37 The use of mineral trioxide aggregate (MTA) for apexification. A, A combination of luxation injury and crown fractures led to pulp necrosis in the central incisors. After pulp extirpation, the canals were medicated with calcium hydroxide for 2 weeks, followed by placement of MTA in the apical portion of the canals. B, After the MTA had cured, the coronal portions of the canals were filled with bonded resin and the access cavities were restored with composite. C, Two years later, the radiograph shows good periradicular repair and evidence of apical hard tissue. (Courtesy of Dr. Mahmoud Torabinejad.)

The most common observation of intruded primary teeth is a yellow crown discoloration, indicating pulpal calcification. No treatment is indicated for such teeth unless pulp necrosis and apical periodontitis occur81 (see Figure 15-38). Tooth Avulsion An avulsed tooth is completely displaced out of its socket; this trauma has also been referred to as an exarticulation.85

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Endodontics

Figure 15-38 Luxation injury to primary tooth. A, After injury to the right primary central incisor, the crown showed discoloration, but the tooth was otherwise asymptomatic. B, The radiograph shows no displacement of the tooth. C, Six months later, the discoloration is no longer present, and D, the radiograph shows that the pulp has undergone calcific metamorphosis as a response to the trauma. (Courtesy of Dr. Mitsuhiro Tsukiboshi)

Description and Incidence. Teeth can be avulsed in many trauma situations. Sports and automobile accidents are the most frequent causes. The incidence of avulsion is reported to be less than 3% of all dental injuries.85 Tooth avulsion is a true dental emergency since timely attention to replantation could save many teeth.85 Unfortunately, avulsed teeth are usually lost at the accident scene, and both accident victims and those attending them may neglect to consider the value of finding and saving the teeth. This may gradually change as the public continues to become aware of the possibilities that avulsed teeth can be saved. Examination. The patient should be carefully examined regardless of whether the tooth has been replanted before coming to the dental office. Radiographs and clinical examination are necessary to help detect possible

alveolar fractures. Such fractures of the tooth socket may reduce the prognosis but are not always a contraindication. Examine the tooth carefully for debris or contamination. Record the time of the avulsion. The length of extra-alveolar time determines both treatment procedures and prognosis. If the tooth has been left dry for less than 1 hour or kept in milk for no more than 4 to 6 hours, the protocol for treatment is described as “immediate” replantation; more than 1 hour of dry time is “delayed” replantation.1,11,85 Treatment: Immediate Replantation. Treatment success for avulsed teeth can be directly related to the extra-alveolar time before replantation: the sooner an avulsed tooth is replanted, the better the prognosis.86 With that in mind, dentists and their staff should be prepared to advise parents and others who may call to report a tooth avulsion (Table 15-2).

Endodontic Considerations in Dental Trauma

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Figure 15-40 Injury to primary teeth led to defects in crowns of succedaneous central incisors.

Table 15-2

B Figure 15-39 Discolored primary teeth indicating pulp trauma. A, The left primary central and lateral incisors have been retained by ankylosis, whereas the permanent right incisors have already erupted. B, Another case; both primary central incisors have necrotic pulps, evidenced by discoloration and labial swelling over apices (open arrows).

Often the person calling is not able to follow instructions to replant the tooth. Rather than waste time trying to explain a procedure to someone who is not prepared to follow the steps described, it is often more practical to urge that the patient and the tooth be brought immediately to the dental office. The manner in which the tooth is transported is important and needs to be explained to the person who accompanies the patient. The ideal way to transport the tooth is to have it replaced in its socket, even if it will need to be repositioned in the dentist’s office.86 Hank’s Balanced Salt Solution has been recommended as a transport medium to be kept in places where avulsion may occur.87 Milk is more readily available and can serve satisfactorily for several hours to maintain cell vitality.88,89 The least favorable medium is water; however, that is better than allowing the tooth to dry. If no milk is available, or while milk is being obtained, the tooth should be kept in the vestibule of the patient’s mouth (or saliva) if possible.1 When the patient arrives, place the avulsed tooth in saline while the examination and preparation for replantation take place. Saline will support the survival of peri-

Guidelines for Replantation

Ideally, if an avulsed tooth can be replanted at the site of injury, the prognosis is better than waiting until the patient is transported to a treatment facility. The following advice can be given over the telephone to someone able to assist the victim: 1.

Rinse the tooth in cold running water. The purpose is to rinse off any obvious debris that may have collected on the root surfaces.

Do not scrub the tooth. The less the root surface is touched, the less damage to fibers and cells. Suggest that the person applying these first-aid measures handle the tooth by holding on to the crown of the tooth and not the root.

Replace the tooth in the socket. Many individuals, even parents, may be squeamish about this step. A relatively easy way out is for the first-aid person to place the tooth, root tip first, partly into the socket, then let the patient bite down gently on a piece of cloth such as a handkerchief to move the tooth back into its normal, or nearly normal, position.

Bring the patient to the dental office right away to complete the treatment of replantation.

odontal ligament cells on the tooth’s root surface and allow the time necessary to prepare for treatment.90 Replantation in the office (Figure 15-41) must be preceded by a careful evaluation of the traumatized alveolus and the avulsed tooth. Radiograph the alveolar segment involved and any other oral area that appears also to have been injured. Look for evidence, both clinically and radiographically, of alveolar fracture. Inspect

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E Figure 15-41 Replantation of avulsed tooth; the extra-alveolar time was less than 1 hour. A and B, The patient brought the tooth in his mouth. In the office, the tooth was placed in saline while the alveolar socket was examined. C and D, The avulsed tooth was replanted and splinted; the lacerated gingiva labial to the adjacent lateral incisor was sutured. Two weeks later, the splint was removed and endodontic therapy initiated. E and F, One year later, the tooth is functioning well, the tissues have healed, and, radiographically, the replantation looks satisfactory. (Courtesy of Dr. Mitsuhiro Tsukiboshi.)

Endodontic Considerations in Dental Trauma the alveolar socket for foreign bodies and debris, taking care not to scrape the bony walls. The blood clot in the socket can be gently suctioned and the socket irrigated with saline. Check the avulsed tooth for debris on the root; if such debris cannot be rinsed off with saline or water, gently pick it off with cotton pliers. While inspecting the tooth, it can be held by the crown with a pair of extraction forceps. This permits examination of the tooth without touching the root surface. After examining the alveolus and the tooth, begin replantation. Gently insert the tooth into the socket; anesthesia will probably not be necessary. The insertion should be slow and gentle so that pressure is minimized. When the tooth is nearly in place, have the patient complete the process by biting on a piece of gauze. Even small children will be able to follow the instruction to bite gently, and it allows them a measure of participation in the treatment. The following steps in the replantation treatment also apply to situations in which the tooth may have been replanted before the patientâ&#x20AC;&#x2122;s arrival. Check it for alignment with respect to adjacent and opposing

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teeth. It is most important that it not be in hyperocclusion. Such premature contact would delay or prevent recovery.85 Next, evaluate the need for stabilization. Splinting may not be necessary if the tooth fits firmly in its socket. If there is mobility, however, it should be stabilized with a functional splint (see Figure 15-25). Use either a thin orthodontic wire (0.3 mm) attached with acidetched resin to the labial surfaces of the replanted and adjacent teeth or use only an unfilled resin bonded to small etched labial spots. In mixed dentition and cases of missing, nonreplaceable adjacent teeth, other types of splints may be necessary.1,85,86 The splint should be left in place only long enough for the initial reattachment of periodontal ligament fibers; in most cases, that can be expected to take place in 1 to 2 weeks, after which the splint should be removed 1,85,86 (Figure 15-42). Further support of the replantation procedure consists of initial antibiotic coverage, tetanus prevention, and root canal therapy. The latter is ideally performed 10 to 14 days after replantation.

Figure 15-42 A, Replanted tooth splinted for 7 days. A normal periodontal ligament (PDL) is evident in this 4-month specimen. B, Replanted tooth splinted for 30 days. Replacement and inflammatory resorption covered the apical half of the tooth. b = bone; c = cementum; d = dentin. Reproduced with permission from Nasjleti CE, Castelli, WA, Caffesse RG. Oral. Surg 1982; 53:557.

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Antibiotics should be administered from the time of replantation; prescribe a dosage regimen similar to that recommended for a mild to moderate dental infection. Coverage for 5 to 7 days should suffice.85,91 If the patient has not had a tetanus vaccination, referral to a hospital or physician is indicated. If the patient has had a vaccination, but more than 5 years have passed since the vaccination or any subsequent booster injections, a booster injection following the replantation is necessary. The optimal time for root canal therapy in a replanted avulsed tooth is about 10 to 14 days after replantation.85,89,92 The only exception to the rule of root canal therapy for avulsed teeth is when the tooth is still developing and has a wide open apical foramen93â&#x20AC;&#x201C;95 (Figure 15-43). Such teeth have the potential for pulp revascularization. If the replanted tooth falls into this category, monitor its progress carefully with frequent, periodic radiographs. If the pulp does not revascularize, it will become necrotic and lead to the same postreplantation sequelae that can be expected from any replanted tooth that has not been treated endodontically: inflammatory resorption (Figure 15-44). Calcium hydroxide has been recommended as an intracanal medication during root canal therapy.85,96,97 Based on current evidence,89,92,97â&#x20AC;&#x201C;99 it appears reasonable to use calcium hydroxide for canal disinfection

(about 2 weeks), and in situations in which resorption has begun, use the calcium hydroxide until resorption has ceased. The completion of the root canal treatment must include a proper root canal filling and a protective coronal restoration. Treatment: Delayed Replantation. The treatment for teeth with more than 1 hour of extra-alveolar time includes efforts to slow the inevitable replacement resorption: 1. Examine the avulsed tooth for debris. In contrast to avulsed teeth with less than 1 hour extra-alveolar time, those with more than 1 hour are not expected to retain the vitality of periodontal ligament cells and fibers. Therefore, it is best to remove pieces of soft tissue attached to the root surface. This needs to be accomplished without overtly scraping the root surface.1,11,85 2. Perform root canal therapy with the tooth in vitro. This can often be best accomplished by holding the tooth by the crown and proceeding with the endodontic treatment through an apical approach. Cut off 2 to 3 mm of the root apex to expose the root canal, extirpate the content of the canal and pulp chamber, and then fill with gutta-percha and sealer. An advantage in doing root canal therapy this way, along with convenience, is that the crown of the tooth can be left intact.

Figure 15-43 An avulsed left central incisor in a 6-year-old boy was replanted immediately. A, When re-evaluated after 8 weeks, there was still response to electric pulp testing. B, One year after trauma, the tooth was in the normal position and had no discoloration but did not respond to electric pulp testing. The root has continued to develop and the pulp appears to be calcifying. Also note hourglass erosion/resorption cervically (arrows). (Courtesy of Dr. Robert Bravin.)

Endodontic Considerations in Dental Trauma

3. Soak the tooth in a 2.4% fluoride solution acidulated at pH 5.5 for 20 minutes or more. The fluoride will slow the resorptive process.1,85 4. Prepare the tooth socket by gently curetting the blood clot out of the alveolar socket and then irrigate with saline.1,85 5. Rinse the tooth thoroughly in saline and then insert it into the socket and splint for 6 weeks.1,85 6. An additional procedure that is showing promise in reducing resportion is to fill the tooth socket with Emdogain (Biora, Inc, Chicago, Illinois) prior to replantation.100

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Figure 15-44 Replanted avulsed tooth in which revascularization did not occur. A, Radiograph of a left central incisor taken 2 weeks after replantation. Note the open apex. B, Radiograph taken 4 months later shows aggressive inflammatory resorption. In an effort to try to keep the tooth for some time, the pulp was extirpated, and calcium hydroxide was placed in the canal. C, Six months later, the radiograph shows remarkable response to treatment—an indication of the result that could have been accomplished if endodontic therapy had been initiated much earlier.

Because replanted teeth with more than 1 hour of extra-alveolar time are expected to resorb and ankylose, it is probably reasonable to expect only a limited length of service from such teeth.101 However, if the resorption is relatively slow, several years of service may result, and this is probably reason enough for performing this relatively simple procedure. It must be noted, however, that in young patients, such ankylosis can result in a lack of alveolar ridge development, so when infraocclusion becomes apparent in a growing child, it may be advisable to remove the crown in a process termed “decoronation” to allow proper ridge development.102

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Endodontics

Avulsed Teeth with Open Apices. The only exception to the rule that replanted teeth must be treated endodontically is the situation in which a very immature, developing tooth with a wide open apex has been avulsed and replanted (see Figure 15-43). Such teeth have the potential for revascularization and therefore should be monitored after replantation to look for signs of revascularization (ie, continued root formation and absence of resorption and ankylosis).95,103,104 It has been recommended to soak the avulsed tooth in a solution of doxycycline (1 mg/20 mL saline) prior to replantation.11,104 Primary Teeth. Most authors advise against replantation of primary teeth unless ideal conditions exist to prevent trauma to the permanent succedaneous tooth.105 Prognosis and Follow-up Evaluation. Resorption is the most frequent sequela to luxation injuries; three different types of resorption have been identified: surface, inflammatory, and replacement (ankylotic) resorption106–108: • Surface resorption: small superficial cavities in cementum and outermost dentin. This type is not

visible on radiographs and is usually repaired by new cementum. It may be transitory or progressive. The former leads to repair, the latter to further resorption (see below). Surface resorption is usually detectable only histologically and probably represents part of the process that takes place both during recovery and as a prelude to more severe resorption.107 • Inflammatory resorption: radiographically seen as a bowl-shaped resorptive area of the root and associated with adjacent bony radiolucencies. It involves both tooth structure and adjacent bone. Radiographically, there is apparent tooth loss along with adjacent bony destruction. This type of resorption is typical in the apical area involving any tooth with a necrotic pulp; replanted teeth that have not had root canal treatment often show these resorptive lesions laterally as well as apically. Root canal therapy can be expected to arrest inflammatory resorption that involves replanted teeth; the resorption can be prevented by judicious timing of the root canal therapy. Optimally, that is about 10 to 14 days post replantation1,11,85,86,106 (see Figure 15-44). • Replacement resorption: resorption of the root surface and its substitution by bone, resulting in anky-

Figure 15-45 A, Reattachment of a replanted tooth treated enzymatically with hydrochloric acid, hyaluronidase, and glutaraldehyde. B, Control tooth, untreated and replanted, with extensive inflammatory and replacement resorption. Reproduced with permission from Nevins AJ, La Porta RF, Borden BG, Lorenzo P. Oral Surg 1980; 50:277.

Endodontic Considerations in Dental Trauma

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losis (Figure 15-45). This is a frequent sequela to replantation. As tooth structure is resorbed, it is replaced with bone that fuses to the tooth structure, thereby producing ankylosis. Root canal therapy has no effect on replacement resorption (Figure 15-46). Replacement resorption can be expected in replanted teeth in which the root surface elements have become necrotic, usually owing to the drying effect of too long extra-alveolar time. Teeth not replanted within 1 hour of avulsion can be expected to fall into this category.106,107 Facial Skeletal Injuries

Figure 15-46 Radiograph showing replacement resorption 5 years after replantation of an avulsed tooth with more than 2 hours extraalveolar time. Note infraocclusion owing to the ankylosis.

Fractures of the Alveolar Process and the Mandible and Maxilla. These are closed fractures or comminutions (crushing or compression) that involve the socket walls in the case of the alveolar process fractures and may or may not involve the tooth sockets in fractures of the body of the mandible or the maxilla109 (Figure 15-47). It was common practice in the past to remove teeth located in a jaw fracture line. Today, however, it is recognized that removal of such teeth does not improve the prognosis for the bone fracture. With the use of antibiotics, fractures involving teeth can be treated conservatively.109â&#x20AC;&#x201C;114

Figure 15-47 A, Alveolar fracture (arrows) and displacement of right canine treated by repositioning the tooth. B, A few weeks later symptoms indicative of apical periodontitis developed, and root canal therapy was performed. (Courtesy of Dr. Eugene Kozel.)

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Endodontics

Figure 15-48 Panoramic film of an 8-year-old patient after a bicycle accident. In addition to maxillary anterior crown fractures, the left temporomandibular condyle also fractured.

Examination and Diagnosis. Fist fights and bicycle and traffic accidents account for most cases of jaw fractures. The most frequent locations are in the mandible— the angles near the third molars and the canine areas.110 Teeth involved in the fracture lines should be pulp tested; a transitory negative response is common, and of the teeth not responding initially, about 25% can be expected to recover.112 Locating the fracture and identifying the involved teeth are the basic considerations in the examination of this group of injuries. Treatment. Initial treatment consists of reduction of the fracture and stabilization by splinting for 3 to 4 weeks.112–114 Analgesic and antibacterial supportive treatment is needed. Stabilization must be carefully done because persistent dislocations increase the chances for pulp necrosis in affected teeth. Stabilization should be carried out as soon as possible.112 The length of time between trauma and treatment adversely affects the prognosis of involved teeth.111 Unless concomitant tooth fractures occur, no treatment of the teeth is needed initially. Prognosis and Follow-up. Although teeth involved in jaw fractures need not be extracted and may help stabilization, 25 to 40% develop pulp necrosis and in time develop periradicular lesions.111,113 For that reason, follow-up evaluation is important and should be done at 3-, 6-, and 12-month periods after initial treatment. Yearly examination for several years alerts one to pulp complications necessitating treatment intervention. Although it may not be mandatory to treat all teeth not responding to the EPT, it should be noted that in one report, all five such teeth that were opened were found to have necrotic pulps.111–113

Temporomandibular Joint A blow to the mandible may result in injuries to the temporomandibular joints. In young children, the condylar necks are rather thin and can easily fracture, particularly if the blow causes a retrusive force on the mandible115 (Figure 15-48). Clinically, traumatized joints may be painful to palpation; in more severe injuries, mandibular function may be compromised, and the patient may have difficulty moving the lower jaw.116 Immediate care of temporomandibular joint injury involves jaw stabilization and symptomatic treatment of joint pain. Careful evaluation, both radiographic and clinical, must be made to determine what, if any, definitive treatment will be necessary. Fractures of the condylar neck with displacement of the condylar head are usually treated by closed reduction in young children. The displaced condyle remodels well to a normal upright position.117 The main factors to remember about trauma involving the temporomandibular joints are (1) to not overlook the possibility of such fractures, particularly in young children,115 and (2) that preventive measures—seatbelts and airbags in cars and face and mouth protection in sports—can be very effective in reducing injuries.2 REFERENCES 1. Andreasen JO, Andreasen FM, Bakland LK, Flores MT. Traumatic dental injuries—a manual. Copenhagen; Munksgaard; 1999. 2. Padilla R, Dorney B, Balikov S. Prevention of oral injuries. Can Dent Assoc J 1996;24:30. 3. Andreasen JO, et al. Replantation of 400 avulsed permanent incisors. Endod Dent Traumatol 1995;11:51.

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