The purpose of this study was to investigate the effect of the untreated immature replanted incisors on periodontal healing. The materials were 6 beagle dogs with permanent dentition whose maxillary left and right second incisors were extracted, replanted and physiologically (semi-rigid) splinted. Root canal treatment (pulp extirpation and calcium hydroxide dressing) was performed only on the right side incisor one week after replantation. On the same day, the splints were removed on both the left and right. At regular intervals during this study, we checked tooth mobility and the Gingival Index (GI) and took intraoral radiographs and intraoral photographs. The results were as follows.
1. The tooth mobility data and GI score were analyzed statistically and no significant differences were seen until 5 weeks after replantation, but significant differences were observed at 5 weeks after replantation onward.
2. The intraoral radiographs and general intraoral photographs suggested that untreated replanted incisors caused a worse outcome in terms of periodontal healing. The differences became clearer after 5 weeks after replantation.
The above results suggest the importance of diagnosis before 5 weeks after replantation by the tooth mobility test and other clinical examinations in determing whether root canal treatment for immature replanted permanent teeth is needed.