Periodontal healing after replantation of intentionally rotated teeth with healthy and denuded root surfaces

Abstract – The purpose of the study was to evaluate periodontal healing after replantation of intentionally rotated teeth with healthy and denuded root surfaces. Ten teeth with hopeless prognoses because of extensive alveolar bone loss and deep pockets extending to the apexes only on one or two surfaces, but with a healthy periodontal apparatus on the other surfaces, were selected. A mucogingival flap was elevated and the teeth were extracted carefully so as not to damage the healthy remnant of the periodontal membrane remaining on the root surfaces. Thorough extra‐oral debridement was performed on the contaminated root surface and the remnant was carefully conserved. Retrofilling was also done to eliminate an endodontic cause of attachment loss. The teeth were horizontally rotated and then replanted so that the healthy root would face the connective tissue at the initially periodontally involved sites, and the root planed surfaces, which had been periodontally involved, would face the surfaces of the alveolar sockets at initially healthy sites. The teeth were splinted with adjacent teeth. Clinical parameters and radiographic examination were performed pre‐operatively, and at 3 or 6 months, 1, 2, and 3 years postoperatively. One tooth was extracted 1.5 years postoperatively due to reduced support and the treatment strategy of the patient. The other nine teeth were well maintained without any discomfort for the whole maintenance period of 3 years. In all teeth, areas that previously had no pocketing but were now against denuded root surfaces maintained the previous pocket depth readings. In areas where a deep pocket was present but now had a root surface with healthy periodontium, a distinct decrease of mean pocket depth was observed at the first reexamination 3 months postoperatively. The mean radiographic alveolar bone level increased from 0.3% to 45.3% in 2 years and was thereafter maintained for the entire observation period. Loss of periodontal space and possible root resorption were observed in only one case without other ankylotic symptoms. These results suggest that the healing without ankylosis of an extensive denuded root surface may occur by mechanisms other than the maintenance of a viable periodontal ligament on the root surface.     

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.     

Pulp capping of immature teeth with anatomic anomalies

Abstract This case report describes the treatment of two immature teeth with anatomic anomalies which created plaque retentive areas and in one case occlusal disturbance. Periodontal and pulpal consequences were inevitable. Reshaping of the teeth was carried out which as expected led to exposure of the pulp in both instances. Pulp capping was then performed under aseptic conditions. The vitality of the teeth was maintained and continued root development was observed.     

年轻恒牙牙髓再生的临床应用进展

目前,对于未发育成熟、根尖孔未闭合的牙髓坏死和根尖周炎的年轻恒牙,临床上主要的治疗方法为根尖诱导成形术,但根尖诱导成形术预后发生根折的概率较大.随着牙髓再生术临床成功病例报告的逐渐增多,越来越多的患者接受牙髓再生治疗.本文收集国外2010—2015年的35篇文献92例病例进行总结并分析,对牙髓再生术的临床应用进展作一综述.     

Periodontal healing of extracted dogs' teeth air-dried for extended periods and soaked in various media

Abstract The aim of this study was to determine the periodontal healing of replanted dogs’ teeth which, after extended extra-oral dry times, had been soaked in various media before replantation. Incisors and premolars of beagle dogs were root canal treated, extracted and bench dried. The teeth were grouped according to dry times of 30, 45 and 60 minutes. Each group of teeth was soaked in one of three media, Hank's balanced salt solution, Via Span (Belzer UW-CSS, Dupont Pharmaceuticals), or Conditioned Medium (supernatant of confluent culture of human gingival fibroblasts) for 30 minutes before replantation. Controls consisted of teeth extracted and replanted without drying or soaking (negative control), and bench-dried teeth replanted without soaking in the media (positive control). The dogs were killed 6 months after replantation of the teeth, which were prepared for histologic evaluation. Five um cross-sections (every 70 Jim) of the root and surrounding tissue were evaluated for healing/resorption according to Andreasen's criteria. The best healing occurred for the roots which had been immediately replanted. Healing in the positive control groups decreased with increased dry time. For the 30–minute dry time groups, soaking in media had no beneficial effect on periodontal healing compared with the controls. Soaking in ViaSpan resulted in an increased healing incidence for both the 45- and 60- minute bench-dried groups while soaking in the other media had no consistent beneficial effect. It appears from this study that an avulsed tooth that has been left dry for 30 minutes should be replanted immediately without soaking. However, teeth that have been dry for 45 or 60 minutes would benefit from soaking for 30 minutes in ViaSpan.     

Periodontal healing in teeth with periapical lesions

Abstract The purpose of the present investigation was to compare clinical periodontal healing in periodontally involved teeth with and without pulpal pathosis. The investigation was conducted as a retrospective study on a consecutive referral population. The periapical conditions in endodontically involved single-rooted teeth from a selected patient sample were evaluated and correlated with their periodontal healing pattern. Multiple regression analysis of the registered variables showed that initial mean pocket depth and time elapsed after treatment significantly influenced change in pocket-depth. Non-surgical treatment of periodontal pockets exceeding 2.5 mm in teeth with horizontal marginal defects, over the observation period, showed significantly reduced mean pocket depth reduction in teeth with periapical pathology compared to teeth without periapical pathology. It was, furthermore, evident that proximal restorations, abutments for fixed bridges and root fillings with and without dowels did not significantly influence pocket depth reduction in the present material. It was concluded, based on the present results, that a root-canal infection, evident as a periapical radiolucency, if left untreated may in the long term perspective result in retarded or impaired periodontal healing following periodontal therapy and, consequently, should be given appropriate consideration when coordinating endodontic therapy and periodontal treatment.     

根管内血运重建用于年轻恒牙牙髓坏死的治疗

近年来随着生命科学、材料科学以及相关各学科的发展,人们对年轻恒牙的再生能力有了新的认识。再生性牙髓治疗作为牙髓坏死后一种新的治疗方式,因其可能带来的较传统治疗方法更为理想的预后开始成为研究的热点。其中根管内血运重建以其简便易行,成本相对较低,不涉及免疫排斥和伦理问题等优势获得了人们的关注。本文将就该治疗方式的发展历史及其在年轻恒牙牙髓坏死治疗中的应用等方面作一综述。     

Healing following reimplantation of teeth subjected to root planing and citric acid treatment

The aim of the present study was to examine the effect of citric acid treatment on periodontal healing around teeth which were extracted, root planed and then reimplanted. Maxillary incisors and mandibular incisors, premolars and molars of 5 monkeys were used. The teeth were divided into 3 experimental groups. In 1 group, the teeth were extracted and immediately reimplanted into their own sockets. In a 2nd group, the teeth were extracted, root planed to a level corresponding to 50-75% of the root length and then reimplanted. In the 3rd group, periodontal breakdown extending to 50-75% of the root length was first induced by placing orthodontic elastic ligatures around the teeth. They were then extracted and root planed and transplanted into the sockets of the contralateral, periodontally healthy teeth which had just been extracted. Half the number of the teeth of groups 2 and 3 were treated with citric acid before reimplantation or transplantation. The animals were sacrificed after 6 months of healing. The jaws were removed and histological specimens prepared for microscopic examination. With the exception of a limited coronal regrowth of new cementum in the apical part of the planed portion of a few roots, connective tissue attachment failed to reform on most root surfaces deprived of their periodontal ligament tissue. Healing was most frequently characterized by root resorption and ankylosis. These were the most predominant features of healing both on root surfaces which had been deprived of the ligament tissue by mechanical means or during a course of experimentally-induced periodontal disease, and occurred in citric acid as well as non-citric acid treated roots. The findings imply that the result of healing following tooth reimplantation or transplantation is determined by the type of cells that repopulate the wound area adjacent to the denuded root surface.     

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.     

2015年南京市353例年轻恒牙外伤的临床分析

［摘要］目的 探讨学龄儿童年轻恒牙外伤的临床特点,更好地维护口腔健康。方法 对2015年1月至12月期间在南京医科大学附属口腔医院儿童口腔科就诊的353例5~12岁学龄儿童年轻恒牙外伤病例的年龄、性别、外伤后就诊时间、外伤牙位、外伤类型及Nolla分期进行回顾性分析,总结其临床特点。 结果 男女比例为2.33∶1;12月份最高发;7～9岁为高发年龄;多在外伤后2~24 h就诊;上颌中切牙最多见;釉质-牙本质折断及亚脱位最多;硬组织损伤中以Nolla 9期最常见。 结论 年轻恒牙外伤有其独有的特点,应加强牙外伤的预防保健宣传,提高公众的就诊意识。     

Effect of minocycline on healing of replanted dog teeth after extended dry times

Abstract  – Minocycline is available as a locally administered tetracycline derivative antibiotic (Arestin™, OraPharma, Inc., Warminster, PA, USA) which demonstrated antibacterial activity and anti-inflammatory action that may slow down resorptive processes after severe traumatic injuries to the dentition. A total of 48 premolar roots of six mongrel dogs were instrumented in an aseptic fashion with rotary nickel-titanium files and obturated with vertically condensed warm gutta percha. All accesses were sealed with glass ionomer, the roots extracted and then allowed to bench dry for 60 min. Group 1 consisted of 15 roots that were coated with minocycline and replanted and nine roots that were replanted without minocycline. Group 2 consisted of 24 roots, all of which were prepared with a uniform cemental defect down to sound dentin along the lateral aspect of the root, with a high-speed bur following the 60-min dry time. Half of the roots ( 12 ) were then coated with minocycline and replanted, and the other 12 roots were replanted without minocycline. After 4 months, the dogs were killed and the roots prepared for histological evaluation. About 5-µm thick cross-sections of the root and surrounding tissue taken every 90 µm were evaluated for healing. In addition, residual root mass was also measured in the roots of group 1 to determine the extent of root structure loss for each treatment method. The roots with and without minocycline treatment showed no significant differences between the remaining root mass or the percentage of favorably healed root surfaces. The use of minocycline is not currently recommended for prevention or attenuation of external root resorption following avulsion in a dog trauma model.     

Tissue reactions after experimental luxation injuries in immature rat teeth

Abstract Immature permanent teeth often develop complications after luxation injuries. The pathology and the degenerative processes of the complications, however, are not well understood. In this study, we histologically examined the long–term reactions of immature rat teeth after standardized luxation injuries delivered in our previously developed experimental model. The upper first molars of 3-week-old male Wistar rats weighing 50-60 g were pushed horizontally toward the palate to cause a constant amount of dislocation. The follow-up changes of the luxated molars were studied up to 56 days after the trauma. Soon after the trauma, the periodontium had irregular fibers, degenerated cells, hemorrhage and edema in various places. After 12 h, a cell free area appeared in the palatal periodontium. In the alveolar bone and on the surface of the root, resorption occurred one day and 5-7 days after injury respectively. Although the damage in the periodontium and alveolar bone was gradually repaired, the root resorption, especially in the palatal cervical region, continued throughout the experimental period. In the most cases, the dental pulp did not seem to be damaged immediately after the trauma. By the 3rd day after injury, however, displacement of odontoblasts into the dentinal tubules was observed in many teeth. Moreover, formation of irregular dentin was observed in some teeth after 7 days. These changes of the pulp tended to disappear in the later stages of the experiment.     

Delayed apical healing after apexification treatment of non-vital immature tooth: a case report

Abstract— We report the endodontic treatment of a non-vital permanent immature tooth in which unexpected complications such as exacerbation of apical periodontitis followed by external root resorption occurred after that the initial stages of the healing process were clinically and radiographically evident. After continued treatment stable repair was obtained.     

Pulp revascularization for immature replanted teeth: a case report

Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8‐year‐old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30 minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21 days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow‐up period, periapical repair, apical closure and calcification in the apical 4 mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra‐alveolar period and maintained in a viable storage medium may be treated with revascularization.     

Periodontal healing of replanted dog teeth stored in Viaspan, milk and Hank's balanced salt solution

Abstract This study examined, histologically, periodontal healing and root resorption of replanted dogs teeth stored in Viaspan for different time periods and compared these healing patterns to those after storage in milk or Hank's balanced salt solution (HBSS). Seventy-two beagle incisors were endodontically treated, extracted, randomly divided and placed in Viaspan or milk for 6, 12, 24 and 36 h, and Viaspan or HBSS for 36, 48, 72 and 96 h, after which they were replanted. Four negative control teeth were immediately replanted while four positive controls were allowed to dry for one hour before replantation. All replanted teeth were splinted for 14 days. Two months after replantation the clogs were killed and the teeth histologically examined for healing of the supporting tissues. For Viaspan neither replacement nor inflammatory root resorption was seen after 6 and 12 h storage. A statistically significant rise in the incidence of replacement resorption was seen at 24, 36 and 48 h which decreased again at 72 and 96 h to levels equal to storage for 6 and 12 h. The occurrence of inflammatory root resorption was low and significantly increased only at 48 h after which it decreased significantly again. Viaspan proved superior to milk as a storage medium. Teeth stored in HBSS showed healing results similar to those stored in Viaspan.