Chapter 15 ENDODONTIC CONSIDERATIONS IN DENTAL TRAUMA

Transcription

1 Chapter 15 ENDODONTIC CONSIDERTIONS IN DENTL TRUM Leif K. akland 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 event 1 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. 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. s ndreasen has pointed out, the initial treatment should not add more trauma to already injured tissues. 4 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 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 ND 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 utomobile 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. 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 s 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

2 796 Endodontics 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 abuse 10 : 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. CLSSIFICTION 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 ndreasen and ndreasen. 5 This classification is used by the International ssociation 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). EXMINTION 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. bloody lip appears more dramatic, but a concomitant broken Table 15-1 Dentofacial Injuries Soft tissues Lacerations Contusions brasions 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 vulsion Facial skeletal injuries lveolar process maxilla/mandible ody of maxillary/mandibular bone Temporomandibular joint

3 Endodontic Considerations in Dental Trauma 797 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. lso 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. ll of this may be highly pertinent if legal or insurance problems later develop. How did the injury happen? This question can provide important information. 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. ffirmative 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 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. llergic reactions to medications. ecause 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. ecause 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 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.

4 798 Endodontics Figure 15-1, Lacerated lips and cheeks should be radiographed for embedded tooth fragments., 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). C Facial ones 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. lso 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. lso check for discoloration of the crown or changes in translucency to fiber-optic light. oth 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

5 Endodontic Considerations in Dental Trauma 799 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 lveolus 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 for some time. ut 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 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

6 800 Endodontics 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. 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 t 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 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,

7 Endodontic Considerations in Dental Trauma 801 Figure 15-4 Maxillary left central incisor developed an apical abscess 30 years after a traumatic basketball accident., Note labial swelling (open arrows) and, apical radiolucency. Pulp did not respond to an electric pulp test, and the crown was slightly discolored. Figure 15-5, Fistulous tract traced with gutta-percha point from labial orifice to, 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). TRUMTIC 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. Tooth Fractures 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 infractions 22 can be seen by indirect light or transillumination or by the

8 802 Endodontics 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 ndreasen 5 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. ecause 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- Figure 15-6 Sequelae to injury that initially produced only an enamel fracture,, but includes, in part, pulpal necrosis, arrested root development, and apical periodontitis. Note crown discoloration in, 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.

9 Endodontic Considerations in Dental Trauma 803 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 follows : nesthetize 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. pply 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. pply 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 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. (lternatively, 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 C D Figure 15-7, Uncomplicated fracture, central incisor. The dentin has been temporarily covered with glass ionomer., 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 years after incisal fragment reattachment. (Courtesy of Dr. Mitsuhiro Tsukiboshi.)

10 804 Endodontics Follow-up and Prognosis. s 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 ndreasen and ndreasen 22 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. acterial 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. oth 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 dentist 30,31 (Figures 15-8 and 15-9). fter 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. llow plenty of coolant water spray to irrigate and prevent heat damage to the subjacent pulp tissue. fter 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. pply the calcium hydroxide over the wound and also cover all exposed adjacent dentin. 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. fter 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 n alternative to the use of calcium hydroxide is a new material, mineral trioxide aggregate (MT)

11 Endodontic Considerations in Dental Trauma 805 C D Figure 15-8 Shallow pulpotomy., Crown fracture exposes pulp., Remove pulp tissue with a round diamond bur to a depth of about 2 mm; use water spray to cool the diamond. C, fter 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.

12 806 Endodontics C D E F Figure 15-9, Crown fracture exposing pulp., Patient 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, cid-etched composite restoration. (Restoration by Dr. James Dunn.) F, Radiograph taken years after accident. Note continued root development (arrow).

13 Endodontic Considerations in Dental Trauma 807 (ProRoot MT, Tulsa Dental/Dentsply, Tulsa, Okla.), which has found many uses in endodontics. 32 It has been shown to be very effective in vital pulp therapy (Figure 15-10). The technique for managing a traumatic pulp exposure using MT 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. shallow pulpotomy is done to provide space for the MT. 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. leeding is allowed to stop (which usually takes 2 to 3 minutes) before MT 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 MT; 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 MT is not as difficult as it often can be when used for other purposes, such as repair of perforations. The mixture of MT 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. small amount of MT should be placed on the wound surface and gently tapped with a moist cotton pellet so that it covers the exposed Figure 15-10, Complicated crown fractures with pulp exposure in both central incisors., 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. C D

14 808 Endodontics pulp. Next, the entire access into the pulp should be filled in a similar manner using small amounts of MT. ny excess moisture should be removed from the surface of the MT using a dry cotton pellet. 5. The rubber dam can then be removed, and the patient can be dismissed. Leaving the MT exposed to saliva will allow it to cure. 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 research 34,35 has shown that the pulp responds favorably to the protection provided by an MT layer. The reparative dentin is consistently more uniform and thicker under MT compared with calcium hydroxide. s 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 MT appears to perform better than any material with which it has been compared. The differences in the vital pulp therapy technique when MT 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 MT; 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 MT 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 MT 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 MT. 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. ut 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 Heide 28 and Cvek 29 indicate that it may be safe to proceed with shallow pulpotomies up to 1 week post fracture. fter 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. number of studies have evaluated the prognosis of traumatized anterior teeth, including those with crown fractures 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. cceptable results of evaluation following pulpotomy should be all of the following 42 : 1. No clinical signs or symptoms 2. No evidence of periradicular pathologic changes 3. No evidence of resorption, either internal or external 4. 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

15 Endodontic Considerations in Dental Trauma 809 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 oxide 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 s in anterior teeth, two types of crown-root fractures are recognized in posterior teeth: those with and those without pulpal involvement. 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 placement 49 (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. ndreasen and ndreasen 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. ecause 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. ngulations of films should include both additional horizontal and vertical angulations. Figure 15-11, Crown-root fracture of the chisel type extending below the alveolar crest palatally., Such teeth may be orthodontically extruded for restorative reasons.

16 810 Endodontics C D E Figure 5-12 Crown-root fracture with pulp exposure., Note loose mesial crown fragments, which are attached by periodontal ligament fibers., fter 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, fter 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, fter placement of base, acid-etched composite will be used for final restoration.

17 Endodontic Considerations in Dental Trauma 811 Figure Vertical root fracture of an endodontically treated tooth., Radiograph shows characteristic drooping lesion (arrows) around the root of a premolar with a very large diameter but short post., 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 surgical 51 or orthodontic 52 can also be done to allow better restoration of the fractured tooth. See Figures and 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. oth 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-

18 812 Endodontics C D E F G H Figure asic technique for root extrusion., Root fracture at or below crestal bone., 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 ) 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 90- degree 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 segment 53 (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

19 Endodontic Considerations in Dental Trauma 813 C D E Figure 15-15, 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., dequate 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.