Dental injuries have been classified according to a variety of factors, such as etiology, anatomy, pathology, or therapeutic considerations. The classification is based on a system adopted by the World Health Organization (WHO) in its Application of International Classification of Diseases to Dentistry and Stomatology. The classification includes injuries to the teeth, supporting structures, gingival, and oral mucosa and is based on anatomical, therapeutic, and prognosticating considerations. This classification can be applied to both permanent and primary teeth.
Stabilization, improvement, or reestablishment of function and aesthetics in traumatized teeth (and their periodontal support) remains a challenging endeavor, particularly when restorative procedures must be performed in emergencies or within a limited period following the trauma. The long-term prognosis of traumatized tissues requires restoration of functional integrity, tooth vitality, and prevention of root resorption.
CLASSIFICATION OF DENTAL TRAUMA
Injuries To Hard Dental Tissues And The Pulp
1. Enamel infraction.
2. Enamel fracture (uncomplicated crown fracture).
3. Enamel-dentin fracture (uncomplicated crown fracture): a fracture with loss of tooth substance confined to enamel and dentin, but not involving the pulp.
4. Complicated crown fracture.
5. Uncomplicated crown-root fracture.
6. Complicated crown-root fracture.
7. Root fracture.
Injuries To The Periodontal Tissues
2. Subluxation (loosening).
3. Extrusive luxation (peripheral dislocation, partial avulsion).
4. Lateral luxation.
5. Intrusive luxation (central dislocation).
6. Avulsion (exarticulation).
Injuries To The Supporting Bone
1. Comminution of the mandibular or maxillary alveolar socket.
2. Fracture of the mandibular or maxillary alveolar socket wall.
3. Fracture of the mandibular or maxillary alveolar process.
4. Fracture of mandible or maxilla.
Injuries To Gingiva Or Oral Mucosa
1. Laceration of gingival or oral mucosa.
2. Contusion of gingiva or oral mucosa.
3. Abrasion of gingiva or oral mucosa.
TREATMENT OF PERMANENT TOOTH FRACTURES AND PROGNOSIS
1. Enamel infraction. Pulpal sensitivity is controlled by sealing or bonding the incomplete enamel fracture. Prognosis is good and expected complications include pulp necrosis.
2. Enamel fracture (no dentin exposed). Removal of sharp enamel edges and corrective grinding or restoration with composite resin. Prognosis is good and expected complications are pulp necrosis, pulp canal obliteration, and root resorption.
3. Enamel-dentin fracture, no pulp exposure. Immediate (provisional) treatment is to place a calcium hydroxide liner over exposed dentin and enamel. Prognosis is good and expected complications are pulp necrosis.
4. Enamel-dentin fracture with pulp exposure. Immediate treatment to the exposed pulp tissue is by pulp capping, pulpotomy, or pulpectomy (root canal therapy). The prognosis is guarded to good for pulp vitality and good for endodontically treated teeth.
PARTIAL CORONAL PULPECTOMY
Pulp capping implies that the pulpal wound caused by the injury is covered with calcium hydroxide and a glass ionomer cement or restorative. Pulpotomy involves removal of damaged or inflamed tissue to the level of clinically healthy pulp, following by calcium hydroxide dressing and glass ionomer cement and composite restoration. Pulpectomy involves removal of the entire pulp, cleaning and shaping the root canal, and obturation with a sealer and gutta percha points followed by crown restoration. Pulpotomy is the treatment of the existing exposed vital pulp in the tooth in an effort to preserve its vitality and to allow the tooth to strengthen through continued growth as long as possible. Several terms are used to further define the general term pulpotomy. These include vital pulpotomy, partial coronal pulpectomy, calcium hydroxide pulpotomy, formocresol pulpotomy and glutaraldehyde pulpotomy. Intracanal medications must be carefully selected so as not to induce adverse reactions.
A vital pulpotomy is also completed after elective crown amputation. A pulpotomy is best performed when a tooth has been fractured no longer than three to six hours. This is the treatment of choice in young animals as long as the pulp is vital—sometimes as long as two weeks post-insult. The length of time between injury and examination will directly affect the health of the pulp. As a rule, pulps that have been exposed for less than a week are acceptable for pulpotomy. The prognosis is poorer the longer the pulp is exposed. The pulpotomy procedure is intended to preserve the vitality of the pulp tissue for continued dentin production. The term “partial coronal pulpectomy” is more appropriate for use in veterinary dentistry. Generally, reentry and conventional root canal obturation is not performed unless there are other indications.
Indications for Partial Coronal Pulpectomy
1. Remaining coronal structure is sufficient for restoration in a vital pulp exposure in an immature tooth (incomplete root development).
2. Vital pulp exposure in a young animal with a mature tooth and large pulp canal with remaining sufficient coronal tooth structure.
3. Elective coronal reduction for relief of occlusal trauma or disarming of aggressive animals.
If there is an unknown duration of vital pulp exposure with activation of pulp hemorrhage and no indications of endodontic pathology, then this tooth may be treated by partial coronal pulpectomy. This is a frequent presentation in veterinary dentistry. Client education must include the possibility of complications that will require reentry and endodontic obturation. A pulpotomy is an acceptable procedure when an animal has to be disarmed (coronal reduction). To leave an open and exposed pulp canal after disarming is an invitation to infection and litigation.
This surgical procedure requires sterile technique. Surgical preparation with rubber dam technique, surgical drapes, caps, masks, gloves, and sterile instruments is indicated.
After evaluation of dental radiographs, the pulp chamber is entered and the pulp is removed down to about the cervical level of the tooth. Avoid the cervical level of pulp, which is important in dentin production and contributes to the strength of the tooth. Approximately 5 to 10 millimeters of pulp are removed using a water-cooled round diamond bur in a high-speed handpiece. Gently wash the pulp with saline and place a moist cotton pellet on the pulp until the bleeding stops. Then wash the pulp again before placing a pulp dressing. Calcium hydroxide is introduced over the pulp tissue as a powder. Exposed dentin should be coated also. A glass ionomer is placed over the calcium hydroxide pulp dressing. A crown restoration is completed using a direct bonded composite restorative.
Placement of a light cured unfilled resin placed over the pulp tissue without placement of calcium hydroxide has also been described, as well as CO2 laser vital pulpectomy techniques.
If the pulp bleeding does not stop after five minutes, remove 2 to 3 millimeters of pulp. If hemorrhage continues, proceed with conventional endodontic pulpectomy and obturation techniques. Assessment of successful vital pulp is made with dental radiographs at six weeks, six months and then yearly. A dentinal bridge may be evident indicating a successful procedure. However, success may be seen without an obvious dentinal bridge. Periodic reassessment with radiographs is the only method of determining a successful procedure.
Endodontic Treatment Of Tooth Fractures
Clinical signs of teeth that require endodontic treatment have been outlined in various sources. Teeth with periodontal disease may progress to induced endodontic disease
Treatment of Tooth Luxations and Prognosis
1. Concussion and subluxation (loosening). Relief of occlusion on the injured tooth and/or immobilization may be indicated, especially in cases of marked loosening. Otherwise a soft diet for 14 days. Check the occlusion and follow-up with radiographs and sensitivity testing at six weeks and six months. Prognosis is guarded to good
2. Extrusive luxation (peripheral dislocation, partial avulsion) and lateral luxation. Treatment is to reposition the tooth in normal position using local anesthesia. In case of delayed treatment, the teeth should be allowed to realign spontaneously into normal position or be moved orthodontically. The tooth should be splinted with an acid-etch resin splint. The splinting period should be, for extrusion, two to three weeks; for lateral luxation, three weeks; and in case of marginal bone breakdown, six to eight weeks. Check the occlusion and follow-up with radiographs and sensitivity testing at six weeks and six months. Prognosis is guarded to good
3. Intrusive luxation (central dislocation). The teeth may normally re-erupt spontaneously. Surgical repositioning has been showed to increase complications such as external root resorption and loss of marginal bone support. Repositioning can be carried out orthodontically over a period of three to four weeks. The gingival lacerations should be sutured with an absorbable suture material. Prognosis is guarded due to the high incidence of root surface resorption.
4. Avulsion (exarticulation). Immediate treatment involves cleaning the tooth gently with saline (no chemicals, do not rub the root surface). Irrigate the socket with a gentle stream of saline (do not curette the socket). Replant the tooth using gentle finger pressure. Apply an acid-etch retained splint. Dispense antibiotics for seven to 10 days. The avulsed tooth will require root canal therapy in two to four weeks post-splinting, which can be completed at the time of splint removal. Check the occlusion and follow-up with radiographs and sensitivity testing at six weeks and six months. Complications include root surface resorption (no treatment), replacement resorption (extraction if progressive, otherwise root canal therapy) and inflammatory resorption (root canal therapy. If there is a socket injury or periodontal ligament injury, then the socket is treated and delayed implantation is the treatment of choice. The tooth is cleaned of periodontal ligament and the socket is curetted. The root canal is filled extraorally. The tooth is placed in a fluoride solution (2.4 % sodium fluoride phosphate acidulated at pH 5.5) for 20 minutes prior to implantation. The tooth is rinsed, reimplanted and splinted. The fluoride will reduce the progression of root resorption by 50%.
Treatment of Injuries To The Supporting Bone and Prognosis
1. Comminution of the mandibular or maxillary alveolar socket. The injury to the alveolar socket generally requires no treatment. Pain management is indicated.
2. Fracture of the mandibular or maxillary alveolar socket wall. The tooth and socket wall is repositioned using local anesthesia. Any loose fragments should be removed. Fracture reduction is by digital pressure. Lacerations of soft tissues should be sutured. The tooth and fracture is stabilized with an acid-etch retained composite splint.
3. Fracture of the mandibular or maxillary alveolar process. Treatment is by reduction and immobilization using a local anesthesia. In this type of fracture, apices of involved teeth can often be locked in place by the vestibular bone plate. Splinting is achieved by acid-etch/resin splint or arch bars for four to eight weeks. Loose teeth should be left in place to insure a stable reduction, but may require extraction at splint removal. Lacerations of soft tissues should be sutured.
4. Fracture of mandible or maxilla. Treatment of jaw fractures is by exact repositioning and fixation. Teeth in the line of jaw fractures should be retained and rigid fixation should be applied. Intraoral splinting using an acrylic composite material is ideal. Placement of plates with screws may be indicated. Care must be taken to avoid placement of screws through tooth roots. The occlusion should be normal and the reduction is checked radiographically. Antibiotic therapy may be indicated for 14 to 21 days. Traumatically damaged teeth can be treated at splint removal. The jaw should be immobilized for eight to 12 weeks, and three to four weeks in immature patients. Check the occlusion and follow-up with radiographs and sensitivity testing at six weeks and six months. Prognosis is guarded to good.
ANTIBIOTICS AND ANALGESICS
Numerous bacteriological studies on endodontic infections show that the predominant microorganisms are facultative and obligate anaerobes. Guidelines for use of antibiotics in veterinary endodontic patients have not been established. The rational use of antibiotics is based on several factors: the proper indication, the effectiveness of the drug against the invading organism, and the toxicity of the drug to the patient. Prophylactic antibiotic regimens are indicated for cardiac patients and patients with systemic disease conditions. Many endodontic infections respond rapidly to root canal therapy and do not require systemic medication. If the antibacterial spectrum were the only criterion, clindamycin would be the drug of choice for treating endodontic infections. It is especially effective against Bacteroides sp. and periapical infections. Penicillin’s are nearly as effective against oral strains of Bacteroides sp. and may be more effective against the gram-positive organisms.
Oral analgesics effectively control postoperative endodontic pain. Clinical pain can be associated with inadequate canal preparation, iatrogenic perforations, over instrumentation and periapical inflammation. Periradicular pain occurs more often in the veterinary patient. If the patient is suffering with pain, then an analgesic is recommended. The nonsteroidal anti-inflammatory drugs, (NSAIDs) such as aspirin and carprofen, act peripherally to control moderate pain. The opioids, such as butorphanol, act centrally and will manage moderate to severe postoperative pain.