Cervical Level Biological Repair of the Access Opening after Regenerative Endodontic Procedures: Three Cases with the Same Repair Pattern

IntroductionThis article describes the regenerative endodontic procedures applied in 3 cases of maxillary incisor necrosis that resulted in continuous root development, dentinal wall thickening, and cervical level biological repair of the access openings that was verified radiographically in 2 cases and clinically in 1 case.MethodsThree maxillary central incisors in 2 different patients were rendered necrotic after having dentin enamel fracture traumatic dental injuries. All teeth were treated with single- or multiple-visit regenerative endodontic procedures.ResultsThe 5- and 9-year follow-up evaluations revealed similar continuous root development, dentin wall thickening, and hard tissue biological repair of the wide access cavities. In the 9-year follow-up case, the calcium silicate cement was removed because of unacceptable discoloration. The hard tissue biological repair was visualized under the microscope and checked for its continuity with the axial walls, its resistance to displacement, and the presence of possible gaps. The repair tissue seemed to be yellowish in appearance with some brown niches of irregular texture, did not have detectable gaps, was firmly connected with the axial dentinal walls through a demarcated white line, and resisted all displacement forces applied. The tooth was restored with bonded composite resin restoration after internal bleaching. The 10-year follow-up revealed satisfactory esthetics and uneventful soft and hard tissue healing.ConclusionsCervical-level hard tissue repair of the access opening after the application of regenerative endodontic procedures in necrotic immature maxillary incisors might reinforce the weakened tooth structure to a great extent and warrants further investigation.     

Root resorption and apical breakdown during orthodontic treatment of a maxillary lateral incisor with dens invaginatus

Abstract— A 13-year-old girl was referred for endodontic treatment of a maxillary right lateral incisor with root resorption and apical radiolucency after orthodontic treatment. Radiographically the tooth had an invagination canal (Oehlers' Type III) and responded positively to pulp testing. The invagination canal extending to the lateral resorption was opened. Vital bleeding tissue was found, and the canal was cleaned and obturated. The pulp in the main root canal remained vital. The radiolucent lesion gradually decreased during the 3-year follow-up. The bone resorption seen here, despite vital tissue in the invagination canal, was probably due to osteoclastic activity caused by a low grade chronic infection, influenced by an injury-induced inflammation in the periodontiurn during orthodontic treatment.     

Histologic and Electron Microscopic Characterization of a Human Immature Permanent Premolar with Chronic Apical Abscess 16 Years after Regenerative Endodontic Procedures

Previous studies have reported successful clinical outcomes after regenerative endodontic procedures (REPs) for immature permanent teeth with pulpal infection. However, it remains unclear whether the procedures promote true regeneration or repair. This case report describes the histologic and electron microscopic characteristics of a human immature permanent premolar with a chronic apical abscess that was treated with an REP. Tooth #20 of a 9-year-old girl underwent an REP. At the 6-year follow-up, the patient was asymptomatic, and closure of the apex and thickening of the dentinal walls were observed. However, 16 years after the procedure, apical periodontitis recurred, necessitating apical surgery. The resected root fragments were obtained during the surgery and analyzed using micro–computed tomography, light microscopy, and scanning electron microscopy. Distinct dentinal tubules and interglobular dentin were observed in the regenerated hard tissue. Cementum-like tissue and a root canal were also observed in the apical fragment. The regenerated root tissue in this case exhibited a structure similar to the native root structure. Therefore, we believe that cell-free REPs possess regenerative potential for teeth diagnosed with pulp necrosis and chronic apical abscess.     

Regenerative Endodontic Treatment with Orthodontic Treatment in a Tooth with Dens Evaginatus: A Case Report with a 4-year Follow-up

Dens evaginatus is a developmental tooth anomaly in which an extra cusp or tubercle protrudes on the occlusal surface of the tooth along with some pulpal tissue. Because of the fragile nature of the protrusion, these teeth are often at risk of pulpal exposure. When this occurs in an immature tooth, regenerative endodontic treatment may be a good treatment approach to promote root formation. There is limited literature that documents the occurrence of orthodontic treatment in teeth that have undergone regenerative endodontic therapy using triple antibiotic paste. Here we present a case of an immature premolar tooth with dens evaginatus that was diagnosed with pulp necrosis and chronic apical abscess. The tooth was treated with regenerative endodontic treatment; after which, the patient received orthodontic treatment with fixed appliances for 2 years. The tooth responded favorably to the regenerative endodontic treatment and orthodontic tooth movement. Clinically and radiographically, all the follow-up examinations revealed an asymptomatic tooth with evidence of periapical healing with stunted root development. The tooth remained asymptomatic even after 4 years. The regenerative endodontic procedure (REP) was successful in treating an immature permanent premolar with pulp necrosis and apical periodontitis with dens evaginatus. In this case, the tooth treated with an REP responded to orthodontic treatment similar to the nonendodontically treated teeth. Further studies are recommended to clarify the precise effects of orthodontic treatment on teeth treated with an REP.     

Endodontic-orthodontic relationships: a review of integrated treatment planning challenges

Literature review There is a paucity of information on the concise relationship between endodontics and orthodontics during treatment planning decisions. This relationship ranges from effects on the pulp from orthodontic treatment and the potential for resorption during tooth movement, to the clinical management of teeth requiring integrated endodontic and orthodontic treatment. This paper reviews the literature based on the definition of endodontics and the scope of endodontic practice as they relate to common orthodontic-endodontic treatment planning challenges. Literature data bases were accessed with a focus on orthodontic tooth movement and its impact on the viability of the dental pulp; its impact on root resorption in teeth with vital pulps and teeth with previous root canal treatment; the ability to move orthodontically teeth that were endodontically treated versus nonendodontically treated; the role of previous tooth trauma; the ability to move teeth orthodontically that have been subjected to endodontic surgery; the role of orthodontic treatment in the provision for and prognosis of endodontic treatment; and, the integrated role of orthodontics and endodontics in treatment planning tooth retention. Orthodontic tooth movement can cause degenerative and/or inflammatory responses in the dental pulp of teeth with completed apical formation. The impact of the tooth movement on the pulp is focused primarily on the neurovascular system, in which the release of specific neurotransmitters (neuropeptides) can influence both blood flow and cellular metabolism. The responses induced in these pulps may impact on the initiation and perpetuation of apical root remodelling or resorption during tooth movement. The incidence and severity of these changes may be influenced by previous or ongoing insults to the dental pulp, such as trauma or caries. Pulps in teeth with incomplete apical foramen, whilst not immune to adverse sequelae during tooth movement, have a reduced risk for these responses. Teeth with previous root canal treatment exhibit less propensity for apical root resorption during orthodontic tooth movement. Minimal resorptive/remodelling changes occur apically in teeth that are being moved orthodontically and that are well cleaned, shaped, and three-dimensionally obturated. This outcome would depend on the absence of coronal leakage or other avenues for bacterial ingress. A traumatized tooth can be moved orthodontically with minimal risk of resorption, provided the pulp has not been severely compromised (infected or necrotic). If there is evidence of pulpal demise, appropriate endodontic management is necessary prior to orthodontic treatment. If a previously traumatized tooth exhibits resorption, there is a greater chance that orthodontic tooth movement will enhance the resorptive process. If a tooth has been severely traumatized (intrusive luxation/avulsion) there may be a greater incidence of resorption with tooth movement. This can occur with or without previous endodontic treatment. Very little is known about the ability to move successfully teeth that have undergone periradicular surgical procedures. Likewise, little is known about the potential risks or sequelae involved in moving teeth that have had previous surgical intervention. Especially absent is the long-term prognosis of this type of treatment. During orthodontic tooth movement, the provision of endodontic treatment may be influenced by a number of factors, including but not limited to radiographic interpretation, accuracy of pulp testing, patient signs and symptoms, tooth isolation, access to the root canal, working length determination, and apical position of the canal obturation. Adjunctive orthodontic root extrusion and root separation are essential clinical procedures that will enhance the integrated treatment planning process of tooth retention in endodontic-orthodontic related cases.     

Recommendations for using regenerative endodontic procedures in permanent immature traumatized teeth

Abstract –  The regeneration of immature permanent teeth following trauma could be beneficial to reduce the risk of fracture and loss of millions of teeth each year. Regenerative endodontic procedures include revascularization, partial pulpotomy, and apexogenesis. Several case reports give these procedures a good prognosis as an alternative to apexification. Care is needed to deliver regenerative endodontic procedures that maintain or restore the vitality of teeth, but which also disinfect and remove necrotic tissues. Regeneration can be accomplished through the activity of the cells from the pulp, periodontium, vascular, and immune system. Most therapies use the host’s own pulp or vascular cells for regeneration, but other types of dental stem cell therapies are under development. There are no standardized treatment protocols for endodontic regeneration. The purpose of this article is to review the recent literature and suggest guidelines for using regenerative endodontic procedures for the treatment of permanent immature traumatized teeth. Recommendations for the selection of regenerative and conventional procedures based on the type of tooth injury, fracture type, presence of necrosis or infection, periodontal status, presence of periapical lesions, stage of tooth development, vitality status, patient age, and patient health status will be reviewed. Because of the lack of long‐term evidence to support the use of regenerative endodontic procedures in traumatized teeth with open apices, revascularization regeneration procedures should only be attempted if the tooth is not suitable for root canal obturation, and after apexogenesis, apexification, or partial pulpotomy treatments have already been attempted and have a poor prognosis.     

Cyst-like periapical lesion healing in an orthodontic patient: a case report with five-year follow-up

AimTo report the orthodontic movement of two central incisors through the healing site of a maxillary cyst-like lesion of endodontic origin after nonsurgical treatment.Case summaryThis report shows the treatment of a 18-year old patient, male, with a Class II division 2 malocclusion. He came to our attention seeking for orthodontic treatment.Radiographic examinations revealed a large cyst-like lesion in the maxillary anterior area, extending from the mesial surface of tooth 12 to the distal surface of tooth 21. The two upper incisors were nonresponsive to pulp sensitivity tests. Endodontic treatment was performed first. One week after root canal treatment had been completed with gutta-percha fillings, orthodontic treatment was started while the bone lesion healing was still underway. At the end of the orthodontic treatment, incisor retroclination was corrected, periapical lesion healing was completed and there were no signs of root resorption. The five-year follow-up revealed that occlusal relationship and dental alignment were kept stable and excellent radiographic resolution of the periapical lesion was obtained.     

Double 'pink tooth' associated with extensive internal root resorption after orthodontic treatment: a case report

Abstract –  Advanced internal resorption affecting the crown of teeth may result in the appearance of a 'pink tooth', which, when located in the root canal, can perforate the external root surface. Therapeutically, this condition represents a clinical challenge and normally requires a combined endodontic and surgical focus. Presented herein are cases of double 'pink tooth' which appeared at different times after orthodontic treatment. In the most severe case, upon radiographic examination and computed tomography, the maxillary right central incisor presented an internal resorption, extending from the pulp chamber to the root middle third. After pulp removal, the debridement of the defect was performed using a 2.5% sodium hypochlorite solution, a #80 Kerr file, and an ultrasonic tip ST-17, aided by a surgical microscope. During the cleaning process, various sites of periodontal communication were identified. Upon controlling the hemorrhaging, the root canal was completely filled with White mineral trioxide aggregate. Within the 3-month follow-up treatment, a pink spot appeared on the maxillary left central incisor, which received conventional root canal therapy. Clinically and radiographically, over 18 months of follow up, both cases responded favorably to the proposed treatments. Therefore, it is important to monitor the patient due to the fact that pulp and periodontal sequelae can develop at varied moments after orthodontic treatment. Furthermore, with the current technology and biomaterials, it is possible to resolve cases with extensive internal perforating resorption through endodontic treatment.     

Critical appraisal of studies on dentinal radicular microcracks in endodontics: methodological issues,contemporary concepts,and future perspectives

The dentinal radicular microcrack is a difficult clinical problem to diagnose and treat, and it is one of the most common reasons for tooth extraction. These microcracks start in the radicular dentin, and laboratory studies have linked crack formation to some routine endodontic procedures, namely root canal preparation, obturation, and retreatment. Most of these studies were performed using destructive methods, such as the sectioning technique, previously developed for the study of the internal anatomy of teeth. Nowadays, technological advances in the field of imaging may lead to a more thorough understanding of dentinal microcracks. This article seeks to critically appraise the methodological aspects involved in the study of dentinal radicular microcrack formation after root canal preparation, obturation, and retreatment.     

Ingrowth of Mineralized Tissue into the Root Canal of Immature Permanent Teeth after a Traumatic Injury: A Report of 3 Cases

The aim of this case series was to describe the endodontic management of 3 immature permanent teeth that sustained traumatic injuries and subsequently presented with complete ingrowth of mineralized tissue into the canal space. Ingrowth of bone/mineralized tissue into the canal has been considered a poor long-term outcome with an inherent risk of ankylosis. In cases 1 and 2, no endodontic treatment was undertaken, except for emergency management requiring splinting. The cases were followed for 36 and 23 months, respectively. No ankylosis was evident over the review period, and normal teeth eruption was apparent. In case 1, the tooth was treated orthodontically and was responsive to pulp sensibility testing. In both cases, there was an appearance of an internal periodontal ligament–like space on the inner root wall of the canal. In case 3, 2 years postinjury, pulp necrosis and apical periodontitis occurred, and the tooth was managed with regenerative endodontic treatment consistent with the European Society of Endodontology and the American Association of Endodontists guidelines/recommendations for a regenerative procedure. The case was followed for 8 years after regenerative endodontic treatment. No ankylosis was noted with normal eruption of the teeth. The tooth was responsive to pulp sensibility testing despite the ingrowth of mineralized tissue, which was confirmed clinically.     

Prognosis of permanent teeth with internal resorption: a clinical review

Abstract This study was performed in order to report the clinical features of internal resorption cases and evaluate their prognosis after endodontic treatment. Twenty-seven patients with 28 teeth with internal resorption were referred to our clinic and 20 teeth were treated endodontically. Sixteen teeth had non-perforating internal resorption and were treated by conventional root canal therapy. The remaining 4 teeth had perforating internal resorption and were initially treated by remineralization therapy with calcium hydroxide. The teeth treated by conventional root canal therapy showed clinical and radiographic evidence of healing. However, the remineralization therapy was successful in only one case. The three failed cases were subsequently treated by endodontic surgery. The surgical therapy was unsuccessful in one case due to extensive loss of marginal alveolar bone and increased tooth mobility.     

Regenerative Endodontic Procedures for Traumatized Immature Permanent Teeth with Severe External Root Resorption and Root Perforation

External root resorption (ERR) is often a complication of traumatic injury to the teeth. Traditionally, external inflammatory root resorption is treated with calcium hydroxide. The outcome of ERR, especially replacement resorption, is unpredictable. The purpose of the present case report was to describe regenerative endodontic procedures (REPs) for 1 replanted avulsed tooth with severe external root resorption and root perforation (tooth #9) and 1 extruded tooth (tooth #8). A 9-year-old girl was referred for the treatment of teeth #8 and #9 4 months after the initial trauma. Clinical examination showed that tooth #9 had a sinus tract present near the periapical area, was tender to percussion and palpation, and did not respond to pulp sensibility tests. Tooth #8 responded to pulp sensibility tests. Periapical radiographic and cone-beam computed tomographic examination showed that tooth #9 had a periapical radiolucent lesion and severe ERRs with a root perforation. Tooth #9 was diagnosed with a necrotic pulp and symptomatic apical periodontitis. Regenerative endodontic procedures (REPs) were initiated. Tooth #8 became nonresponsive to pulp sensibility tests and developed a periapical lesion 12 months after REPs of tooth #9 and was also treated with REPs. The clinical symptoms and apical lesions resolved for both teeth after REPs. The severe ERRs were arrested, and root perforation was repaired for tooth #9. Teeth #8 and #9 underwent canal obliteration by hard tissue formation after REPs and were in function at 18 months and 30 months, respectively. REPs may be used to manage traumatized immature permanent teeth with a necrotic pulp and apical periodontitis associated with severe ERR and root perforation.     

Apexogenesis after initial root canal treatment of an immature maxillary incisor – a case report

Aim To present a case where a traumatized, immature tooth still showed capacity for continued root development and apexogenesis after root canal treatment was initiated based on an inaccurate pulpal diagnosis. Summary Traumatic dental injuries may result in endodontic complications. Treatment strategies for traumatized, immature teeth should aim at preserving pulp vitality to ensure further root development and tooth maturation. A 9‐year‐old boy, who had suffered a concussion injury to the maxillary anterior teeth, was referred after endodontic treatment was initiated in tooth 21 one week earlier. The tooth had incomplete root length, thin dentinal walls and a wide open apex. The pulp chamber had been accessed, and the pulp canal instrumented to size 100. According to the referral, bleeding from the root made it difficult to fill the root canal with calcium hydroxide. No radiographic signs of apical breakdown were recorded. Based on radiographic and clinical findings, a conservative treatment approach was followed to allow continued root development. Follow‐up with radiographic examination every 3rd month was performed for 15 months. Continued root formation with apical closure was recorded. In the cervical area, a hard tissue barrier developed, which was sealed with white mineral trioxide aggregate (MTA). Bonded composite was used to seal the access cavity. At the final 2 years follow‐up, the tooth showed further root development and was free from symptoms. Key learning points

• ? Endodontic treatment of immature teeth may result in a poor long‐term prognosis.
• ? The pulp of immature teeth has a significant repair potential as long as infection is prevented.
• ? Treatment strategies of traumatized, immature permanent teeth should aim at preserving pulp vitality to secure further root development and tooth maturation.
• ? Radiographic interpretation of the periapical area of immature teeth may be confused by the un‐mineralized radiolucent zone surrounding the dental papilla.

     

An Assessment of the Effects of Orthodontic Treatment after Apexification of Traumatized Immature Permanent Teeth: A Retrospective Study

IntroductionRoot resorption may occur in traumatized necrotic teeth that have undergone apexification after orthodontic treatment. This study examined the effects of orthodontic treatment on the outcome of apexification.MethodsThis retrospective study included 36 children presenting with anterior permanent traumatized teeth with immature roots who were treated by apexification and root canal treatment. The orthodontic group consisted of 17 children with 24 teeth that were subjected to orthodontic treatment after apexification. The control group consisted of 19 children with 21 teeth that underwent only apexification without orthodontic treatment. Almost half of the teeth in both groups underwent apexification with calcium hydroxide, whereas the other half were treated with mineral trioxide aggregate. The effects of sex, stage of root development, and apexification material on the outcomes of apexification were analyzed and compared between the 2 groups.ResultsApexification was successful in 88% of cases after at least 5 years of follow-up. Neither apexification technique nor sex had a significant effect on treatment outcome. The stage of root development had a positive effect on outcome, although it was not statistically significant. Some root resorption (average = 0.3 mm) was observed after orthodontic treatment, whereas teeth that underwent apexification without orthodontic treatment exhibited some root elongation (average = 0.1 mm). This difference was highly significant.ConclusionsMinor root resorption was observed in the orthodontic group compared with a minor increase in root length in the control group. Orthodontic movement of immature traumatized teeth after apexification appears to be safe.     

Traumatic intrusion of permanent teeth: 10 years follow-up of 2 cases

Abstract – Intrusive luxation is a kind of traumatic injury characterized by an axial displacement of the tooth toward the alveolar bone. Its main causes are bicycle accidents, sports/recreational activities, and falls or collisions. Treatment strategies include waiting for the tooth to return to its position, immediate surgical repositioning, and repositioning through dental traction by orthodontic devices. In order to decide which treatment to follow, the degree of root formation, the patient’s age, and intrusion severity should be taken into consideration. This study aimed to report a 10-year follow-up of two patients that suffered permanent incisor (PI) traumatic injury who had a similar root development (incomplete rooting) but different results. In the first case, the treatment of choice was follow-up. The patient showed gingival alteration and root resorption of tooth 21. Calcium hydroxide therapy and root canal filling were performed twice because of not attending callback. After finishing the endodontic treatment, follow-up visits showed no abnormalities. In the second case, the treatment of choice was watch and wait to the teeth 11 and 21. After 7 months spontaneous eruption of both teeth was detected. Radiographic examination showed atypical root formation and almost completely pulp canal obliteration, 8 years later. In the follow-up, visit after 10 years was observed complete crow and pulp canal obliteration. It was concluded that PI intrusion treatments are good intervention alternatives, as they proved to be successful after a 10-year follow-up period.     

Orthodontic Movement after Regenerative Endodontic Procedure: Case Report and Long-term Observations

Introduction

Although regenerative treatment approaches in teeth with incomplete root formation and pulp necrosis have become part of the suggested therapeutic endodontic spectrum, little is known about the effect of orthodontic movement in the tissue that has been regenerated. Furthermore, as the number of adults undergoing orthodontic treatment increases, there is an increasing need to investigate the changes that these tissues may undergo during orthodontic movement. Here we describe the alterations observed after the application of orthodontic forces in a case of an apically root-fractured necrotic immature root that had been managed with regenerative endodontic procedures in the past.

Allogeneic Cellular Therapy in a Mature Tooth with Apical Periodontitis and Accidental Root Perforation: A Case Report

IntroductionCell therapy in regenerative endodontics introduces an alternative option to classic treatment strategies for complex endodontic cases. The aim of this case report was to describe cell-based therapy using allogeneic umbilical cord mesenchymal stem cells (UC-MSCs) encapsulated in a bioscaffold for a complex case of a mature permanent tooth with apical periodontitis and accidental root perforation.MethodsA healthy 19-year-old man undergoing orthodontic treatment was referred for endodontic treatment in tooth #7; he was diagnosed with apical periodontitis during a previously initiated treatment associated with accidental perforation of the radicular cervical third. The root perforation was sealed with glass ionomer and composite resin, and the root canal was instrumented, disinfected, and dressed with calcium hydroxide. After 3 weeks, allogeneic UC-MSCs were encapsulated in platelet-poor plasma and then implanted into the root canal, and Biodentine (Septodont, Saint-Maur-des-Fosses, France) was placed below the cementoenamel junction. Finally, the tooth was restored with composite resin.ResultsFollow-up examinations were performed 6 months and 1 year later. The examinations included periapical radiography, cone-beam computed tomographic imaging, and sensitivity and vitality tests. Radiographic and cone-beam computed tomographic images indicated remission of the apical lesion. Clinical evaluations revealed normal responses to percussion and palpation tests; the tooth was responsive to the electric pulp test, and the vitality test indicated low blood perfusion units.ConclusionsThis case report reveals the potential use of allogeneic cellular therapy using encapsulated UC-MSCS in a platelet-poor plasma scaffold for a complex case of a permanent tooth with apical periodontitis and root perforation.     

Treatment of inflammatory external root resorption resulting from dental avulsion and pulp necrosis: clinical case report

The aim of this case report was to present a treatment for severe inflammatory external root resorption. The condition developed due to the patient's neglect to seek adequate treatment following replantation of an avulsed maxillary left central incisor. Following diagnosis, treatment consisted of conventional endodontic therapy with calcium hydroxide dressings and definitive filling of the root canal after the resorption was controlled radiographically. A 24-month follow-up showed that the resorption process had stabilized and the patient was free of symptoms. Successful tooth replantation requires following the indicated therapy effectively. Nevertheless, when an inflammatory external root resorption occurs, adequate endodontic treatment to remove the necrotic content and bacteria is required, as is the use of calcium hydroxide dressings.     

Tooth autotransplantation using an interdisciplinary approach to rehabilitation in a young patient: Case report with 7-year follow-up

This case report demonstrates the possibility of functional and aesthetic rehabilitation using an interdisciplinary approach in a child following avulsion of a tooth. Autotransplantation after the development of calcific metamorphosis of the pulp and acute apical periodontitis provided satisfactory repair after root canal treatment. A 7-year-old white boy avulsed the right maxillary central incisor (tooth 11). The extra-alveolar time exceeded 60 minutes, and this triggered external replacement resorption of the avulsed tooth. At 11 years of age, the child underwent tooth autotransplantation. After 4 years of follow-up, intraoral clinical and radiographic examination led to the diagnosis of calcific metamorphosis of the pulp and acute apical periodontitis. The patient had minimally invasive root canal treatment, orthodontic treatment and esthetic rehabilitation with a porcelain crown. Control periapical radiography and tomography of the autotransplanted tooth after 7 years revealed bone repair in the periapical region. This case report indicates that tooth autotransplantation can be used to replace anterior teeth after avulsion followed by replacement resorption. Interdisciplinary management helped to maintain the esthetics and function of the rehabilitated area.     

猫下颌尖牙根管治疗对牙正畸移动的影响

目的：探讨经根管治疗牙的正畸移动可行性及牙根吸收的风险.方法：建立对经根管治疗牙进行正畸移动的动物模型,采用石膏模型测量、病理学和放射学方法评估正畸移动的距离及牙根吸收的程度.16只成年家猫的一侧下颌尖牙在全麻下开髓、拔髓,一次完成根管充填治疗术,随后在正畸弹簧的作用力（100～120 g）下向远中作倾斜移动.8周后测量石膏模型上牙移动的距离,以及根管治疗牙与正常牙的组织学和放射学牙根长度.应用SPSS11.0软件包进行数据分析,均数比较采用配对t检验.结果：实验结果显示,在相同正畸力作用下,根管治疗牙与正常牙移动距离相近（P＞0.05）;组织病理学显示,根管治疗牙牙根的长度比正常牙小（P＜0.05）,但在放射学上,两者的长度无统计学差异（P＞0.05）.结论：在本实验条件下,经根管治疗牙在正畸力作用下能与正常牙同样快速移动,组织学观察显示其根吸收的程度比后者略大.