Periodontal healing after intentional auto-alloplastic reimplantation of injured immature upper front teeth

BACKGROUND/AIMS: Conventional endodontic treatment results in high complication quota when performed in immature teeth. Intentional reimplantation with extraoral insertion of an endodontic implant (auto-alloplastic reimplantation) is an alternative. METHOD: In a retrospective study, the healing of 40 teeth reimplanted intentionally according to this method in patients aged 7 to 15 years was evaluated. Clinical tests (palpation, percussion sound, periotest values) and radiographical examinations were used to determine the type of periodontal healing (inflammatory resorption/periodontitis apicalis; replacement resorption/ankylosis; normal healing). RESULTS: Mean lifetime of the replanted teeth was 59.2+/-42.5 months, estimated survival time on the basis of the Kaplan-Meier analysis was 99.5 months. 17 teeth (42.5%) were classified as failures, mostly due to inflammatory resorption or periodontitis apicalis. Further investigations demonstrated that success rate and retention period of intentionally replanted teeth depend on the preoperative condition of the pulp. Teeth with preoperative infection suffered frequently from inflammatory resorption or periodontitis apicalis after being replanted (14 of 28 teeth). Estimated survival time according to Kaplan-Meier was 75.5 months. In contrast, inflammations or progressive resorptions were not observed in teeth without preoperative infection of the pulp. All these 12 teeth showed normal periodontal healing and regular tooth mobility. In the absence of any pathology in clinical or radiological findings after an average functional period of 72.3 months, the prognosis can be presumed excellent. Estimated survival time of 148.3 months according to Kaplan-Meier differs significantly from survival time of teeth infected preoperatively. CONCLUSIONS: From the results of this investigation, it may be concluded that an infection of the pulp - due to delay of treatment or attempts at endodontic therapy - should be avoided before intentional replantation of immature front teeth with pulp necrosis. Periodontal healing of the autologous root is not impaired by the insertion of posts made of Al2O3-ceramics or titanium. The inserted posts do not ankylose. Orthodontic movement of auto-alloplastically replanted teeth is possible.     

Treatment of root perforation by intentional reimplantation: a case report.

Intentional reimplantation is defined as a procedure in which an intentional tooth extraction is performed followed by reinsertion of the extracted tooth into its own alveolus. In this paper, intentional reimplantation is described and discussed as a treatment approach to root canal instrument separation in conjunction with root perforation. An 8-year follow-up case report is presented. The reimplanted tooth is now a fixed bridge abutment. Although successful in this case, the intentional reimplantation procedure should be considered a treatment of last resort, that is, when another treatment option is not viable for the treatment of root perforation/instrument retrieval.     

Treatment of root perforation by intentional reimplantation: a case report

Abstract— Intentional reimplantation is defined as a procedure in which an intentional tooth extraction is performed followed by reinsertion of the extracted tooth into its own alveolus. In this paper, intentional reimplantation is described and discussed as a treatment approach to root canal instrument separation in conjunction with root perforation. An 8-year follow-up case report is presented. The reimplanted tooth is now a fixed bridge abutment. Although successful in this case, the intentional reimplantation procedure should be considered a treatment of last resort, that is, when another treatment option is not viable for the treatment of root perforatiotdinstrument retrieval.     

Effect of platelet-derived growth factor-BB on root resorption after reimplantation of partially denuded tooth in dog

Abstract – The prognosis for a reimplanted tooth depends largely on the condition of the root. Platelet‐derived growth factor (PDGF)‐BB has been shown to regenerate periodontal tissue in animal and human clinical studies. However, information regarding the effect of PDGF‐BB on tooth reimplantation is limited. The objective of this study was to investigate the effect of PDGF‐BB on root resorption after reimplantation of a partially denuded tooth in dog. A total of 15 healthy female beagle dogs were used. Mandibular third and fourth premolars were endodontically treated and then extracted as atraumatically as possible. The coronal portion of each root was carefully scaled and planed. The roots on the right side of the mandible were treated with PDGF‐BB and reimplanted, while the roots on the left side served as controls. After 2, 4, or 8 weeks, specimens were collected and processed for histopathological examination. By the 4th week after reimplantation, new periodontal ligament (PDL)‐like tissue had formed around the PDGF‐BB‐treated root surfaces and new bone. By the 8th week, healing of the PDGF‐BB‐treated roots was characterized by newly formed PDL with inserting attachment formation. In contrast, control roots showed multiple areas of replacement resorption. Immunohistochemical staining of proliferating cell nuclear antigen (PCNA) performed at 2 weeks after reimplantation showed that the number of PCNA‐positive cells in the connective tissue area was statistically significantly greater in the PDGF‐BB‐treated group than in the control group (P < 0.001). The application of PDGF‐BB resulted in a significantly lower occurrence and extent of root resorption and ankylosis. These results suggest that the use of PDGF‐BB reduces occurrence of ankylosis and root resorption in tooth reimplantation.     

Long-term results after childhood condylar fractures. A computer-tomographic study

A computer-tomographic study of the remodelling process of the TMJ was made of 12 patients who had suffered condylar fractures during their growth period. The most interesting results were exhibited by patients with low fractures of the condyle and medial luxation of the small fragment. The remodelled condyles consisted of 2 parts, a medial part, probably the remainder of the small fragment and a lateral part, probably callus formation. In some patients a flattening of the fossa characterized by thickening of the roof was clearly observed. The case presentation additionally included one patient with post-traumatic ankylosis and one patient presenting a bifid condyle.     

拔牙后不同时机植入种植体的远期效果评价

目的 探讨拔牙后患者单牙种植体早期、延期和晚期植入颌骨后8年锥形束CT（cone-beam CT,CBCT）数据,分析不同时机植入对种植体的影响,为选择拔牙后种植体合适植入时机提供参考。方法 回顾分析2010年1月—2010年12月重庆市北碚区中医院行拔牙术后单牙种植体植入的68例患者的临床资料,根据植入时间不同分为A、B、C 3组,早期植入（拔牙后7 d内）25例为A组、延期植入（拔牙后平均3个月）24例为B组、晚期植入（拔牙后平均1.5年）19例为C组。术后随访8年,比较CBCT图像和前后位（PA）图像显示的周围骨水平及与颌骨缺损的关系。采用SPSS 18.0软件包进行统计学分析。结果 共植入162颗种植体,成功150颗,成功率92.59%。单因素方差分析显示,3组成功率差异显著（P<0.05）;进一步两两比较,C组成功率>B组>A组（P<0.05）。共获取51例患者8年的CBCT图像（早期植入16例、延期植入20例,晚期植入15例）;CBCT和PA图像邻间骨水平差异显著（P>0.05）;3组旋入扭矩和旋出扭矩相比,差异显著（P>0.05）;植入时机、旋入扭矩、旋出扭矩是影响种植体成功率的高危因素（P<0.05）。种植体植入后8年,各组骨水平相比差异显著（P>0.05）;第2阶段手术中C组骨缺损少于A、B组（P<0.05）;无缺损种植体平均颌骨水平（bBL）低于开裂种植体（P<0.05）。结论 拔牙后种植体放置时间对种植体周围颌骨水平无显著影响,但不同时机植入可影响种植体成功率,应严格把握即刻种植适应证。     

Healing after root reimplantation in the monkey

The aim of the present investigation was to evaluate the regenerative potential of the periodontal tissues following tooth reimplantation using a model which excluded the dentogingival epithelium from the process of healing. Maxillary and mandibular incisors, premolars and molars of 5 monkeys were used. Following root filling of all experimental teeth, the teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted following the elevation of full thickness flaps. The crowns were separated from the roots at the level of the buccal cemento-enamel junction and the roots immediately reimplanted into their sockets. The flaps were replaced and sutured to accomplish complete coverage of the roots. In a 2nd group, the teeth were subjected to the same experimental procedure, but in addition, the buccal alveolar bone was removed to about half its original height prior to root reimplantation. The teeth of the 3rd group were subjected to identical experimental procedures as for group II with the addition that the buccal root surfaces were planed to the level of the surgically created bone crest. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. The results showed that a complete fibrous re-attachment formed onto roots on which the original periodontal ligament tissue was preserved. This occurred irrespective of whether the roots were reimplanted into sockets with normal (group I) or reduced (group II) bone height. When the original periodontal ligament tissue was removed by root planing before reimplantation (group III), healing resulted in a significant amount of new connective tissue attachment. However, coronal to the newly formed fibrous attachment, the root surface frequently showed signs of resorption and particularly so in those roots which remained covered by the soft tissue during the entire course of healing. In the majority of the roots which perforated the covering soft tissue during the early phase of healing, the dentogingival epithelium had migrated apically into contact with the coronally generated fibrous attachment. In these cases, root resorption was never discernible. New bone formation occurred to a variable extent in the roots of groups II-III. No relationship was found, however, between the amount of connective tissue reattachment or new attachment and newly formed alveolar bone, which in turn indicates that bone tissue regrowth and periodontal ligament regeneration are unrelated phenomena.