Résumé
@#Tooth avulsion is one of the most serious case of all traumatic injuries, frequently found in the immature permanent teeth. The common treatment for avulsed permanent tooth is replantation and splint fixation. However it usually results in root inflammation, root absorption and ankylosis, eventually lead to extraction. The present report describes a 8-year-old boy with two immature mandibular central incisors avulsed three hours after the accident. Replantation was performed, and the teeth were splinted. Radiographic and clinical examinations were performed during 15 months follow-up. At present, the avulsed teeth have a favorable prognosis, and remained in a stable functional position and did not reveal root inflammation, root absorption and ankylosis.
Résumé
Objective@# To evaluate the efficacy of Mtwo rotary instruments during root canal retreatment. @*Methods @#Thirty mandibular premolars with oval root canal were prepared with ProTaper rotary instruments and obturated with lateral condensation method. The samples were divided into 2 groups. In Mtwo group, the filling materials were removed with Mtwo retreatment system and Mtwo basic instruments. Inmanual stainless group, the filling material were removed with manual instruments. The percentage of residual filling material was measured with image proplus software and the operating time was recorded. @*Results@#The percentage of residual filling material in Mtwo group was significantly lower than manual group in middle third, but the opposite result can be found in the coronal third. In the whole canal, no significant difference was found between the two groups. The mean operating time in Mtwo group was significantly shorter than manual group. @*Conclusion @#Mtwo rotary instruments can shorten the time of retreatment, neither of the groups can remove the filling material in oval root canal completely.