Young Bui, D.D.S.
Root Fractures
Young Bui

Young Bui

ROOT FRACTURES occur in fewer than 8 percent of traumatic injuries to permanent teeth.  When they do occur, hemorrhage from the pulp and periodontal ligament (PDL) flows into the fracture site and clots.  The fractured surfaces of dentin and cementum are gradually remodeled by surface resorption and apposition of calcific tissue.  Root fractures heal differently depending on the degree of separation of the fragments, the severity of injury, and the ability of the pulp to heal.  the differences in healing may take any of the following forms.
    Calcific healing is a form of healing in which a calcific callus is formed at the fracture site on the root surface and inside the canal wall.  This type of healing requires a wide canal with the fragments in close apposition with little or no mobility.  The pulp will be vital and the tooth will have little or no mobility.
    Connective tissue healing is a form of healing in which a fibrous attachment similar to PDL develops between the fractured fragments.  This results when the fragments are separated farther apart or because some mobility is present.  The pulp will be vital and the tooth will have little mobility.  The connective tissue will appear as a fracture line on the radiograph.
    Combined bone and connective tissue healing is healing in which new bone may grow between the fractured segments if further separation occurs or there is mobility of the parts.  The fractured surfaces are lined with cementum with new PDL growing between the tooth and the new bone.  The pulp is vital.
    Healing with nonunion and granulation tissue formation is a form of healing that occurs when the pulp is injured or infected and becomes necrotic due to narrow root-canal space, contamination of the pulp by oral fluids, or severe dislocation of the fractured root.  The pulp tissue in the incisal segment undergoes necrosis and the apical segment will remain vital.  The tooth will be loose and sensitive to percussion, and it may turn dark.
Figure 1
FIGURE 1: Different forms of healing: A, Calcific callus; B, Connective tissue; C, Combination of bone and connective tissue; D, Nonunion and granulation tissue formation

    With most root fracture maintaining vitality of the pulp, the main goal of treatment is to enhance this healing process.  The clinician should try to reunite the fractured segments by calcific callus formation because the tooth will be stronger than one without the union of broken parts.  The fracture should be reduced as soon as possible and the broken tooth firmly immobilized by splinting or bonding to adjacent teeth. 
    There are two types of root fracture:

  • fracture without communication with the oral cavity
  • fracture with oral communication
    The noncommunicating fracture occurs in the apical or middle third of the root.  Perform a vitality test, check for color change in the crown, and record the degree of mobility of each traumatized tooth.  If the pulp is vital, then immobilize the tooth by splinting it to the adjacent teeth.  A radiograph should be taken after repositioning to confirm realignment.  The length of time to leave the splint on ranges from one week to three months or more, depending on the degree of mobility and the location of the fracture.  There is no need to splint the tooth if the fracture is in the apical third with little displacement or mobility.  If the fracture is at the crest of the alveolar bone with modest displacement and mobility, the splint will have to stay for three months or more.
    When the splint is removed, the clinical status of the tooth must be determined.  The degree of mobility, color of the crown, and vitality of the pulp should be recorded.  If the periodontal attachment has failed to heal, the prognosis for healing decreases drastically.  If the tooth responds as normal to a pulp test with little or no mobility and the patient is comfortable, then there is nothing more to do but follow up in six months and a year after that.  If mobility is present, the splint must be reapplied and the occlusion adjusted.  The tooth should be splinted permanently to the adjacent teeth if mobility is present after six months. 
    If the fracture of any part of the root is coronal to the periodontal attachment, the prognosis for healing is poor.  There is periodontal breakdown along the fracture line with pulpal necrosis from the bacterial contamination through the fracture.  The most common type of fracture is seen in the maxillary incisor with the fracture on the labial surface 2-3 mm supragingival but tapering obliquely to 2-5 mm subgingivally on the lingual.  This type of fracture can occur with premolar and molar cusps.  The fractured part should be removed during the emergency visit, and endodontic treatment should be done in one visit.  Once the emergency has been taken care of, plans must be made for restoring the tooth.
September-October 2002
Figure 2

FIGURE 2: Calcific callus formation of the root in an extracted tooth.

Figure 3

FIGURE 3: Endodontic treatment on the coronal segment of a tooth with a horizontal fracture. 

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