Root fracture is defined as a dentin and cementum fracture involving the pulp. Classification is based on the level of the fracture in relation to the apex of the root. The fracture may occur in the apical third, middle third or cervical third of the tooth. The more cervical position the fracture, the worse the prognosis. The apical fragment usually remains in its original position while the coronal fragment is displaced. Since the crown of the tooth is often intact and stable, diagnosis of a root fracture can only be made radiographically and may require multiple radiographic exposures at different horizontal and vertical angulations for an accurate diagnosis. Root fractures in primary teeth may be obscured due to superimposition of a succedaneous tooth.
The treatment objective is to reposition and stabilize the coronal fragment as soon as possible in its anatomically correct position to optimize healing of the neurovascular supply and periodontal ligament and maintain esthetic and functional integrity.
Primary teeth: Treatment alternatives are dependent on the stability of the coronal fragment of the injured tooth. If the tooth is stable and causing no discomfort to the patient, the tooth needs only to be monitored by clinical and radiographic examination post trauma, at two to three weeks, six to eight weeks, six months, one year and then annually until the permanent tooth erupts.
If the tooth is mobile and the patient expresses discomfort, the coronal fragment should be extracted. If the apical fragment is too difficult to retrieve, it should be left to resorb so as not to disturb the developing permanent tooth. The tooth is monitored for apical pathology and normal resorption. Follow up consists of clinical examination and radiographs after three to four weeks.
Permanent teeth: If the coronal fragment is stable and immobile (high apical root fracture), no treatment is indicated. If the coronal fragment is mobile, reposition and stabilize the fragment with rigid splinting of composite resin and wire or orthodontic appliances for four weeks; if the fracture is in the middle third of the root, four months if in the cervical third. If splinting is unsuccessful, the coronal fragment is extracted and endodontic therapy is performed on the apical fragment. Further treatment options for a subgingival root are gingivectomy, orthodontic extrusion or surgical extrusion.
It is uncommon for the apical fragment to develop pulp necrosis. If pulp necrosis of the coronal fragment occurs, there will be radiographic signs of bone loss at the level of the fracture as well as clinical symptoms, such as pain, gingival swelling, excessive mobility and sinus formation. If this occurs:
Extirpate the pulp from the coronal fragment to within 1mm of the fracture line. Do not advance the instrument through the fracture site.
Place calcium hydroxide paste to induce hard tissue bridging at the fracture site. This may take up to 18 months.
Obturate with gutta percha once the bridge has formed.
If the calcium hydroxide fails to form a bridge, an alternative treatment is to place a 4mm thickness of MTA at the apex, allow to harden and obturate with gutta percha.
If the apical fragment shows signs of necrosis, it should be surgically removed and endodontic therapy performed on the coronal fragment.
Follow up clinical and radiographic examinations are scheduled at six months and one year and yearly for five years.