CROWN FRACTURES : Biologic Consequences & Treatment
As mentioned previously, the primary aim from an endodontic point of view is to maintain vitality after these types of accidents. Crown infraction (“incomplete fracture or crack of enamel without loss of tooth structure) and uncomplicated crown fracture (“fracture of the enamel only or enamel and dentin without pulp exposure) are injuries that have little danger of resulting in pulp necrosis. In fact, the biggest danger to the health of the pulp is through clinician-produced causes during the aesthetic restoration of these teeth. Therefore meticulous follow-up over a 5-year period is the most important endodontic preventive measure in these cases. If at any follow-up the reaction to sensitivity tests changes or on radiographic assessment signs of apical or periradicular periodontitis develop or the root appears to have stopped development or is obliterated, then endodontic intervention should be considered.
Complicated Crown Fracture
Complicated crown fractures are crown fractures involving enamel dentin and pulp (Fig. ). They occur in 0.9% to 13% of all dental injuries.
A crown fracture involving the pulp, if left untreated, will always result in pulp necrosis. However, the manner and time sequence in which the pulp becomes necrotic allow much potential for successful intervention to maintain pulp vitality. The first reaction after the injury is hemorrhage and local inflammation (Fig. ). Subsequent inflammatory changes are usually proliferative but can be destructive. A proliferative reaction is favored in traumatic injuries because the fractured surface is usually flat, allowing salivary rinsing with little chance of impaction of contaminated debris. Therefore unless impaction of contaminated debris is obvious, it is expected that in the first 24 hours after the injury, a proliferative response with inflammation extending not more than
2 mm into the pulp will be present (see Fig.). In time, the bacterial challenge will result in local pulpal necrosis and a slow apical spread of the pulpal inflammation .
Treatment options are (1) vital pulp therapy comprising pulp capping, partial pulpotomy, or full pulpotomy or (2) pulpectomy. Choice of treatment depends on the stage of development of the tooth, time between the accident and treatment, concomitant periodontal injury, and restorative treatment plan.