Survival of 534 incisors after intra-alveolar root fracture in patients aged 7-17 years.

The purpose of the study was to evaluate and assess the survival rate of 534 root fractured teeth, including factors that may affect the survival rate but were not included in previous long-term studies. Location of fracture was registered as in the cervical, cervical/middle, middle and apical one-third of the root, and root development was categorized into five stages. Altogether, 383 (78%) showed healing of the fracture, with either formation of hard tissue or interposition of soft tissue between the fragments. In these teeth, no significant difference was found between positions in the root or types of healing. In 325 teeth, the healing remained unchanged throughout the control period, while 58 teeth showed a posthealing complication. A new injury occurred in 47 teeth; in 21 of these, the injury healed spontaneously, in four after endodontic treatment. Increased mobility of the coronal fragment was recorded for 32 teeth, and in 11 of these, the looseness of the fragment was so pronounced that the teeth had to be extracted. No healing, i.e. radiolucency in the alveolar bone, adjacent to fracture, took place in 109 teeth (22%). Of these teeth, 34 were extracted during the observation time while 75 (69%) showed healing after endodontic therapy. At the final assessment of survival (including all parameters) of 534 root fractured teeth, 425 (80%) showed survival and 109 (20%) were extracted during the observation period. It was concluded that the survival of root-fractured teeth was high for up to 10 years of observation (mean = 63 months). The highest frequency of tooth loss (70%) was found in 77 teeth with horizontal fractures restricted to the cervical part of the root. When these teeth were excluded, the frequency of survival in remaining teeth rose to 88%.