Progression of root resorption following replantation of human teeth after extended extraoral storage

Avulsed human permanent teeth subjected to a minimum of 1 h dry extraoral storage before replantation were followed radiographically for an average of 4.8 years. The depth of root resorption cavities was assessed using a radiographic index, and the rate of root resorption was defined as the index change over time. The frequency of inflammatory and replacement resorption was determined at each observation time. Replacement resorption increased in frequency with time in all patients. In teeth endodontically treated within 3 weeks of replantation, minimal inflammatory resorption was found regardless of the age of the patients. In teeth where endodontic treatment was performed more than 3 weeks after replantation, the frequency of inflammatory resorption was significantly higher in young patients but not in older patients, up to more than 3 years after replantation. The rate of root resorption was found to be related to age. In patients 8-16 years old at the time of avulsion the rate of root resorption was significantly higher compared with patients 17-39 years old. Age had a higher impact on the rate of root resorption compared with the delay in endodontic treatment after replantation. It was concluded that a tooth replanted with a necrotic periodontal membrane will become ankylosed and resorbed within 3-7 years in young patients, whereas a tooth replanted under similar conditions in older patients may remain in function for a considerably longer time.     

Histometric study of root resorption on human premolars following experimental replantation

Abstract – A histometric method was applied for evaluation of root resorption in 57 experimentally replanted teeth and 22 controls. Representative axiobuccolingual sections were selected for measurement of resorptions at a magnification of × 40. The frequency of root resorption in the control teeth was low. In replanted teeth marked resorptive activity elicited by the trauma appeared after 2 wk. The extent of active resorptions increased until the third postoperative week. On an average 14% of the root periphery was affected at this stage. After the sixth postoperative week progressive cement deposition took place in the resorption lacunae. Incidental ankylosis of the periodontal membrane also occurred from this observation time but there was no increase among the long-term groups.     

Emdogain® does not prevent progressive root resorption after replantation of avulsed teeth: a clinical study

Abstract –  Emdogain^® has been shown in clinical and experimental studies to promote regeneration of all periodontal tissues: cementum with anchoring fibres, a functional, periodontal ligament and alveolar bone in connection with treatment of marginal periodontitis.
The intention of this study was to analyse whether this regenerative capacity upon the periodontal ligament also worked in a trauma situation where a significant number of PDL cells have been eliminated because of unphysiologic storage or actual damage during avulsion or replantation. Furthermore if ankylosis sites already established because of earlier replantation after avulsion could be surgical removed and application of Emdogain^® could revert the ankylosis stage to a normal PDL situation. The first treatment situation was tested in seven patients with a total of 16 avulsed teeth with varying time of extra oral storage. The teeth were extra-orally endodontically treated and the root and socket covered with Emdogain^® before replantation. All teeth demonstrated subsequent ankylosis, primarily diagnosed by a percussion test. The second treatment situation where an ankylosis was already established constituted of seven patients with a total of 11 teeth because of previous replantation after avulsion. These teeth were all extracted, the ankylosis sites removed and the root and socket treated with Emdogain^®. After 6 months all teeth showed recurrence of ankylosis. It is concluded that Emdogain^® was not able to prevent or cure ankylosis.     

Dynamics of dentoalveolar ankylosis and associated root resorption

Abstract The present experimental studies in monkeys were undertaken to study the initiation and progression of dentoalveolar ankylosis of replanted teeth and associated root resorption. Maxillary and mandibular lateral incisors were extracted and replanted after an extraoral period of 15 min or 1 h. Teeth with an extraoral period of 1 h were endodontically treated. Half the number of monkeys were given antibiotics at the time of replantation. The observation periods varied from 2 days to 40 weeks. Irrespective of the length of the extraoral period, initial root resorption and minor areas of ankylosis were found 1 week after replantation. The initial ankylosis was not preceded by root resorption. In teeth replanted after an extraoral period of 15 min the ankylotic area did not increase with increasing time after replantation. Instead the periodontal membrane was re-established, separating the root surface from the alveolar bone. In teeth replanted after an extraoral period of 1 h, the initial ankylotic area increased with increasing time after replantation. Eight weeks and more after replantation, most of the periodontal membrane was replaced by bone covered by osteoblasts and occasional osteoblasts that were in continuity with the endosteal cells outlining the marrow spaces of the alveolar bone. The cementum and dentin were then gradually resorbed with increasing time after replantation. Antibiotics given at the time of replantation reduced the initial inflammation in the periodontal membrane and the inflammatory root resorption after all observation periods and it also seemed to some extent to prevent bacteria from entering the necrotic pulp tissue. Based on the present results it is suggested that root resorption associated with dentoalveolar ankylosis is initiated by endosteal osteoblasts and is thus a hormonally regulated process. This is in contrast to inflammatory root resorption, which seems to be triggered by inflammatory cells.     

完全脱位牙即刻与延迟再植根吸收的动态观察

目的：动态观察实验大鼠再植牙牙根吸收及愈合过程,辅助临床治疗及预防再植牙牙根吸收。方法：30只6周龄SPF级Wistar雄性大鼠,分为6组,每组5只,其中一组为空白对照组。实验组大鼠双侧上颌第一磨牙脱位后再植,每只大鼠随机选取一侧脱位牙齿即刻再植,对侧同名牙则于体外干燥保存30min后再植回牙槽窝。分别于术后1、3、7、14、21d处死,分离上颌骨,拍摄x线片,应用IPP软件测量上颌第一磨牙近中根根周透影面积。标本脱钙后制作切片、HE染色,进行组织学观察。结果：再植牙根尖周透影面积随时间延长而增大,干燥组表现尤其明显;组织学上表现为初期炎症反应较明显,随着炎症发展,牙根表面吸收陷窝逐渐增多、增大,后期即刻组牙髓及牙周膜修复反应明显,干燥组牙槽骨修复反应强烈,牙根、牙周膜逐渐被类骨质样组织替代。结论：再植牙初期以炎症反应为主,后期主要表现为修复反应,即刻与延迟再植导致牙周膜细胞活性不同决定了再植牙根吸收的进展。     

External root resorption following bleaching of pulpless teeth with oxygen peroxide

Abstract Eleven teeth in which bleaching with 30% oxygen peroxide was followed by external root resorption are presented. One tooth had no traumatic history, while the others were previously subluxated or luxated in accidental injury. Radiographic appearance of resorptions varied. In 2 teeth the resorptions were only superficial and did not progress during the observation time. In 5 teeth the resorptions were associated with ankylosis. In the remaining 4 teeth the resorption was progressive, bowl-shaped and associated with radiolucency in the adjacent alveolar bone. It was suggested that damage to the periodontium, caused by oxygen peroxide at the time of treatment, may heal or be followed by ankylosis and, when complicated by bacterial contamination, develop to a progressive root resorption associated with persistent inflammatory changes in periodontal tissues.     

Effect of masticatory stimulation on dentoalveolar ankylosis after experimental tooth replantation

Abstract Dentoalveolar ankylosis (replacement resorption) is a serious complication after replantation of avulsed teeth. The purpose of the present study was to investigate the influence of masticatory stimulation on dentoalveolar ankylosis after replantation of avulsed teeth. Monkey upper incisors were extracted, air-dried for 1 h, endodontically treated and replanted. No splinting was used. One group of monkeys was given hard pelleted food, while another group was given soft diet during a healing period of 8 wk. The periodontal conditions were evaluated histologically with a morphometrical method. The replanted teeth of the monkeys given the hard pelleted food had significantly less ankylosis and a larger area of the root surrounded by a normal periodontal membrane than the teeth from the monkeys given a soft diet. In conclusion, development of ankylosis seemed to be partially prevented or reduced by masticatory stimulation.     

The effect of intracanal Ledermix on root resorption of delayed-replanted monkey teeth

Abstract – Progressive root resorption is one of the common sequelae in replanted teeth, which is detrimental to their long‐term prognosis. Ledermix paste, with its composition of triamcinolone acetonide and demethylclortetracycline, has been shown to inhibit inflammation and the associated hard tissue resorption. This study evaluated the effect of immediate intracanal Ledermix on root resorption of delayed‐replanted monkey teeth. A total of 36 roots were root canal treated. For the experimental group, intracanal Ledermix was placed prior to extraction and replantation after 1‐h bench dry. The positive control group was root filled and replanted after 1 h while the negative control group was root filled and replanted immediately. The monkeys were sacrificed after 12 weeks. The H&E histological tissue specimens were prepared and evaluated using a method modified from that of Andreasen's morphometric analysis, as favorable or complete healing and unfavorable healing, comprising inflammatory root resorption and replacement resorption. The results were analyzed using Kruskal–Wallis and Mann–Whitney U‐tests as well as Wilcoxon signed ranks test. The negative control group produced highly significant favorable healing and unfavorable healing as compared to the Ledermix group (P = 0.000). The Ledermix group only showed significantly higher occurrence of complete healing (35.46%) compared to the positive control group (16.58%) (P = 0.037) but there were no significant differences in the inflammatory root resorption and replacement resorption. Nevertheless, when the latter two unfavorable healing patterns were combined, there was a significantly lower overall unfavorable healing in the Ledermix group (64.54%) when compared to the positive control group (83.43%) (P = 0.037). This unfavorable healing outcome in the Ledermix group, however, was not significantly different from the favorable healing outcome with the same treatment modality (P = 0.110).     

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 replacement resorption by intentional replantation, resection of the ankylosed sites, and Emdogain®– results of a 6-year survey

Abstract –  The present clinical study investigated the outcome of intentional replantation using resection of the ankylosed sites of the root, extraoral endodontic treatment using titanium posts and Emdogain^® for periodontal healing following trauma-related ankylosis. During an evaluation period of 6 years, 16 ankylosed teeth affected by replacement resorption were treated as described. Evaluation parameters before treatment and during the follow-up period included Periotest^® scores, percussion sound and periapical radiographs. All findings were compared to those of the adjacent teeth. In a second accident, one tooth was lost after 7 months and was excluded as a dropout. Ankylosis did not recur in seven replanted teeth, which were observed for an average of 52.3 months (range: 24–68 months). Ankylosis recurred in eight teeth after an average period of 12 months (range: 4–26 months). An infraocclusion, normal or only slightly reduced Periotest^® scores and normal percussion sound were preoperatively found in six of seven successfully replanted teeth, which corresponded to a relatively small area of ankylosis. The majority of the teeth showing recurrent ankylosis preoperatively presented with normal position, negative Periotest^® scores and a high percussion sound which corresponded to an extended area of ankylosis. Statistically significant relationship between preoperative findings and the treatment outcome ( P  = 0.031) have become apparent. The results indicate that the treatment of minor areas of ankylosis by intentional replantation, resection of the ankylosed sites and Emdogain^® appeared to prevent or delay the recurrence of ankylosis in 7 of 15 teeth.     

Effect of brief storage in ATP solution on periodontal healing after replantation of teeth in rats

Abstract ATP solution seems to increase calcium absorption when applied both to dentin and to the pulp before the application of calcium hydroxide. In this study, the effects of a brief storage of teeth in ATP or saline solution before replantation were compared. The right maxillary incisors of 80 male albino rats were extracted and immersed, either directly or after 25 min air-drying, in ATP or saline solution and then replanted. Eight animals in each group were killed 5, 10, 30, 60 and 90 d after replantation and the teeth were examined histologically. The histometric analysis revealed significant differences between the saline- and ATP-treated group. More new cementum or cementum-like tissue was deposited over the radicular surface in the ATP-treated teeth. More root surface area was resorbed and not repaired by new cementum in the saline group and more total root surface was not resorbed or resorbed and repaired in the ATP-treated group. Based on these findings, it seems reasonable to conclude that brief storage of teeth in ATP solution before replantation may have improved the healing of replanted teeth in rats.     

Avulsed human teeth replanted within 15 minutes — a long-term clinical follow-up study

Abstract Twenty–one avulsed human permanent teeth replanted within 15 min after trauma were followed radiographically for an average of 5 years. Seven teeth did not show any root resorption during the observation period. In 8 teeth shallow resorption cavities were observed, but no signs of progression were observed with increased observation time. In 6 teeth some progressive root resorption was observed with increased observation time. The depth of root resorption cavities was assessed using a radiographic index, and the rate of root resorption was defined as the index change over time. The rate of root resorption was determined. It was concluded that teeth replanted within 15 min after the avulsion have a favourable long-term prognosis.     

Intentional replantation and management of avulsion related ankylosis and external cervical resorption. A 10-year follow up case report

Replantation is the treatment of choice for avulsed permanent teeth; ankylosis and cervical root resorption are among survival complications. A 9.5-year-old boy presented with an avulsed maxillary permanent central incisor with an open root apex following a school accident. The tooth was kept in milk, after a dry time of 15–20 min. Its replantation was performed 60 min after the accident. At 8 months, apexification with apical plug was attempted upon radiographic evidence of apical periodontitis. Ankylosis sound with infraocclusion and radiographic evidence of external cervical root resorption (ECR) were evident at 3 years and 3 months. At the patient's return one year later with esthetic concerns (2 mm infraocclusion) there was a 5 mm diameter ECR cavity. After intentional atraumatic extraction the resorptive cavity was debrided and restored with Biodentine; subsequently the tooth was reimplanted and splinted at an extruded position. At the 10-year follow up since the first avulsion the tooth remains esthetically pleasing, asymptomatic, non-ankylotic and functional. The present case supports intentional replantation as an option in managing infraoccluded teeth with advanced ECR.     

Treatment of replacement resorption with Emdogain®– preliminary results after 10 months

Abstract – Ankylosis of traumatized teeth in children and adolescents may inhibit further development and growth of the corresponding jawbone. Therefore, ankylosed teeth should be removed. As an alternative treatment option to autotransplantation of a premolar, intentional replantation using Emdogain^® may be considered, provided the ankylosis is detected at an early stage or has only affected a small area of the root. Eleven ankylosed teeth presenting with replacement resorption were treated as follows: after tooth extraction, the root canal was treated extraorally and obturated by retrograde insertion of a titanium post. Emdogain was applied to the root surface and into the extraction socket with subsequent replantation of the tooth. During a mean follow-up period of 6.3 months, no signs of recurrence of ankylosis were noted. The horizontally and vertically measured Periotest scores were identical to those obtained on the adjacent teeth. These results suggest that intentional replantation using Emdogain may prevent or delay ankylosis of these replanted teeth.     

人牙周膜成纤维细胞来源外泌体对大鼠延期牙再植术后牙根吸收的调控作用

目的: 探讨健康的人牙周膜成纤维细胞（hPDLFs）来源外泌体对大鼠延期牙再植术后牙根吸收的作用及其可能机制。方法: 分离提取hPDLFs来源的外泌体并鉴定。选择30只6周龄雄性SD大鼠,随机分为对照组和外泌体组,建立上颌第一磨牙延期牙再植术模型,牙脱位30 min后植回牙槽窝。对照组牙周膜局部注射40 μL汉克斯平衡盐溶液（HBSS）,实验组牙周膜局部注射40 μL含外泌体的HBSS。术后1、2、4周收样,苏木精-伊红（H-E）染色观察牙根表面吸收陷窝,抗酒石酸酸性磷酸酶（TRAP）染色观察破骨细胞数量,免疫组织化学染色观察牙周膜内骨保护素（OPG）的表达。采用SPSS 17.0软件包对数据进行统计学处理。结果: 鉴定表明提取的细胞外囊泡为外泌体。与对照组相比,hPDLFs来源的外泌体减少了延期牙再植术后牙根吸收陷窝的数量,降低TRAP阳性破骨细胞的表达（P<0.05）,促进牙周膜内OPG的表达（P<0.05）。结论: 延期牙再植术后,hPDLFs来源的外泌体减少了破骨细胞的数量,促进牙周膜内OPG表达,减少了再植术后的牙根吸收。     

Multiple idiopathic cervical root resorption involving all permanent teeth

Multiple idiopathic external cervical root resorption is a rare condition with numerous predisposing factors that have not yet been clearly elucidated. In addition, its diagnosis and treatment pose challenges for clinicians, and thus, the extraction of the involved teeth is commonly performed. Here, we report a 29‐year‐old pregnant woman with no contributory medical or family/social history who experienced cervical root resorption that progressed aggressively and involved all permanent teeth. This case is unique owing to the involvement of all teeth. Reports of multiple idiopathic external cervical root resorption are rare in the literature, and the pathogenesis of the condition is poorly understood. This report aims to add an additional case to the existing literature, analyse the underlying mechanisms and provide clinicians with some guidance in diagnosing cervical root resorption.     

Cervical external root resorption in vital teeth

External resorptions associated with inflammation in marginal tissues present a difficult clinical situation. Many times, lesions are misdiagnosed and confused with caries and internal resorptions. As a result inappropriate treatment is often initiated. This paper provides three-dimensional representations of cervical external resorption, based on X-ray microfocus-tomographical scanning of a case, which will aid the dental practitioner in recognizing characteristic features during clinical inspection. In addition, histopathological examination reveals the cellular morphology of the adjacent tissues.     

Bone morphology after delayed tooth replantation – case series

The purpose of this report was to describe the morphological changes in the alveolar bone after delayed replantation of avulsed teeth using three dimensional cone‐beam computed tomography in 11 during the time period 2003–2012. The radiographic observations revealed the following: Delayed replantation results in ankylosis‐related replacement root resorption; the resorption is delayed or arrested around the cervical area superior to the alveolar crest. The buccal bone is reduced in thickness but not the palatal bone. The buccal bone resorption of the alveolar crest progresses approximately to the root canal space of the ankylosed root. Delayed replantation does not completely maintain the bone volume. The buccal profile of alveolar bone in the maxillary anterior region is depending on teeth with viable periodontal ligament.     

Tooth avulsion and replantation — A review

Abstract The major causes of post-replantation tooth loss are inflammatory root resorption and root resorption associated with ankylosis. Recent studies have concentrated on delineating the cellular interactions in the pulp and periodontium in order to more fully understand the various factors affecting the prognoses of such teeth. The aim of this report is to discuss the nature of the pathology responsible for tooth loss following avulsion and to review recent replantation and attachment studies.