Transient discoloration of the coronal fragment in intra-alveolar root fractures.

BACKGROUND Root fractures are a relatively rare type of injury with frequencies of 0.5-7% of traumatized permanent teeth. It is well known that teeth with intra-alveolar root fractures have a good prognosis. The pulp remains vital in about 80% of these teeth. If pulp necrosis develops, this normally only occurs in the coronal fragment. Although several studies on intra-alveolar root fractures have been published during the last decades, none have mentioned that transient discoloration can occur. The aim of our study was to study the frequency and prognosis for intra-alveolar root fractures with discoloration. MATERIAL AND METHODS The material consisted of 42 permanent incisors from 21 boys and 18 girls aged 7-19 years (mean = 12.7, median 12.0). In two girls and one boy, two incisors exhibited concurrent intra-alveolar root fractured. The follow-up period ranged from 1 to 9 years. The colour changes were determined at each control by transillumination of the clinical crown from the facial and palatal surfaces. Electrometric sensibility was evaluated and compared to the values of adjacent teeth using an electric pulp tester. At the final clinical and radiographic control, the type of healing was registered. RESULTS Discoloration was found in nine teeth. The root development was completed in all these teeth. The discoloration disappeared within 4 weeks to 6 months in eight teeth. The sensibility, which was lost at the injury, followed the changes in discoloration, and all teeth had regained normal sensibility when the discoloration had disappeared. Only one tooth, which showed a greyish hue, developed pulp necrosis. CONCLUSION Transient discoloration in intra-alveolar fractures is relatively common and is indicative of a good prognosis for healing.