Apical Surgery on Fractured Roots: Case Reports

[Anonymous]

 DISCUSSION

Both of the teeth, described in these 2 case reports, had the roots fractured once. However, it was surgical intervention and removal of occlusal trauma that brought both cases to a successful resolution in the end. What was learned from these cases was the importance of postoperative care, even though the causes of root fractures were hypothetical. The root canals were definitely enlarged by 40% to 50% of the root width, and thus were accordingly susceptible to vertical fracture. Periodontal studies suggest that the lesion of occlusal trauma is an injury to the periodontal ligament structure (the cementum, the periodontal ligament, and the associated alveolar bone). Excessive force can lead to pathologic changes in the periodontal ligament. Reported findings include vasculitis, disorganization of cells and fibers, bone and cementum resorption, necrosis of collagen fibers, and hyalinization of the periodontal ligament. The type of damage depends upon the direction, duration, and magnitude of the force and is limited to the ligament region. 
     The first case presented above revealed that the tooth had once been healed by the nonsurgical endodontic treatment, which was confirmed on the 3-month postoperative radiograph. It then later fractured, possibly after it was restored with a crown. Initially, the tooth had been free from excessive occlusal forces during the endodontic treatment at least until the crown was placed on it. In other words, there had been no excessive forces from occlusion loaded on the tooth during that period, which was confirmed by the reduction of periodontal ligament width on the radiographs. The preoperative radiograph showed the enlarged periodontal ligament around the root, and the 3-month recall radiograph showed the healing of the periodontium; then another 3 months later it was back to what it was on the first visit. Taking all that happened into consideration, there should have been occlusal trauma existing for a certain period of time resulting in the widening of the periodontal ligament, which eventually triggered off the development of root fracture on the tooth. It was also noticed that the widening of the periodontal ligament remained the same even 3 months after the apical surgery, but it was back to normal soon after occlusal trauma was removed from the tooth by the referring dentist. Hence it was obvious that abnormally excessive occlusal force was responsible for the root fracture. The second case here illustrated that the root that lost 40% to 50% of dentin in diameter was susceptible to root fracture, which did occur in the end, possibly when force loaded on the tooth exceeded its limit.

CONCLUSION 
These 2 cases suggest that an endodontically treated tooth needs immediate attention to abnormally excessive force from occlusion after the placement of the crown; so that the tooth, especially the one with canal enlargement of more than 40% of the root width, will remain healthy in the long-term period. However, endodontic success will not always contribute directly to long-term survival of the tooth. There are several factors of endodontic failure. They are residual bacteria colonizing inside or outside the canal system (in the form of biofilms), foreign body reactions to obturation materials, the occurrence of true cysts, and cholesterol crystals. The review of these 2 case reports revealed that the endodontic treatments failed because of the infection that occurred subsequently after root fractures.
Therefore, it was concluded that occlusal trauma was identified as a cause of infection, and postoperative care of occlusion after endodontic treatment played an essential role in the prevention of root fracture for long-term endodontic success.