Regenerative Endodontics: A Potential Solution for External Root Resorption (Case Series)

IntroductionRegenerative endodontic procedures (REPs) are aimed to treat apical periodontitis and promote root maturation of immature necrotic teeth. However, REPs are not intended to be a primary indication for treating or arresting external root resorption (ERR). The purpose of this study was to describe REP treatment in the cessation of ERR.MethodsFour cases (5 teeth) of posttraumatic immature teeth diagnosed with necrotic pulp and apical periodontitis or chronic apical abscess were treated with REPs using plasma-rich fibrin as a scaffold. All the teeth showed ERR and have been followed up to 3 years.ResultsThis case series shows how REPs arrested ERR. In 3 of the cases, replacement resorption was arrested, thus avoiding complications of ankylosis and the need for decoronation.ConclusionsIn addition to the known advantages of REPs, we show that REPs are a promising treatment modality for arresting ERR, warranting further clinical trials.     

An Innovative Regenerative Endodontic Procedure Using Leukocyte and Platelet-rich Fibrin Associated with Apical Surgery: A Case Report

Regenerative endodontic procedures (REPs) associated with apical surgery could represent an alternative treatment strategy for patients whose teeth present incomplete root formation and extensive apical lesions. Leukocyte platelet-rich fibrin (L-PRF) has potential benefits in REPs; it could promote apical root formation and optimal bone healing. The aim of this case report was to describe innovative regenerative endodontic therapy using L-PRF in the root canal and an extensive apical lesion in an immature tooth with dens invaginatus and asymptomatic apical periodontitis. A healthy 20-year-old woman was referred to the dental clinic of the Universidad de Los Andes, Santiago, Chile, for endodontic treatment in tooth # 22 with incomplete root development and an extensive apical lesion. The diagnosis was asymptomatic apical periodontitis associated with dens invaginatus type II. The patient was treated with an innovative approach using L-PRF in REPs associated with apical surgery. Follow-ups were performed at 6 months and 1 year later. They included periapical radiographs, cone-beam computed tomographic imaging, sensitivity, and vitality tests. The clinical evaluations performed at 6 months and 1 year revealed an absence of symptoms. The radiographic evaluations showed that the apical lesion was resolved. The cone-beam images indicated that the root length increased and the walls had thickened. The sensitivity tests were positive, and the laser Doppler flowmetry showed positive blood flow after 1 year. The success of the results in this case report indicate that L-PRF can be used as a complement in apical surgery and REPs and could provide an innovative alternative treatment strategy for complex clinical cases like these.     

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 a Large Cystlike Inflammatory Periapical Lesion Associated with Mature Necrotic Teeth Using Regenerative Endodontic Therapy

Introduction

Regenerative endodontic therapy is currently used to treat immature permanent teeth with necrotic pulp and/or apical periodontitis. However, mature teeth with necrotic pulp and apical periodontitis have also been treated using regenerative endodontic therapy. The treatment resulted in resolution of apical periodontitis, regression of clinical signs and symptoms but no apparent thickening of the canal walls, and/or continued root development. A recent study in an animal model showed that the tissues formed in the canals of mature teeth with apical periodontitis after regenerative endodontic therapy were cementumlike, bonelike, and periodontal ligament–like tissue with numerous blood vessels. These tissues are similar to the tissues observed in immature permanent teeth with apical periodontitis after regenerative endodontic therapy.

Methods

A 23-year-old woman had a history of traumatic injury to her upper anterior teeth when she was 8 years old. Subsequently, #8 developed pulp necrosis and an acute apical abscess and #7 symptomatic apical periodontitis. The apex of #8 was slightly open, and the apex of #7 was completely formed. Instead of nonsurgical root canal therapy, regenerative endodontic therapy was attempted, including complete chemomechanical debridement on #8 and #7. This was based on the premise that filling of disinfected root canals with the host's biological vital tissue might be better than filling with foreign materials.

Results

After regenerative endodontic therapy of #8 and #7, there was radiographic evidence of periapical osseous healing and regression of clinical signs and symptoms. The pulp cavity of #8 decreased in size, and the apex closed. The pulp cavity of #7 appeared to be obliterated by mineralized tissue. These indicated ingrowth of new vital tissue into the chemomechanically debrided canals.

Conclusions

Regenerative endodontic therapy of mature teeth with apical periodontitis and apical abscess can result in the regression of clinical signs and/or symptoms and healing of apical periodontitis but no apparent thickening of the canal walls or continued root development. Filling of the disinfected canals with the host's vital tissue may be better than with foreign materials because vital tissue has innate and adaptive immune defense mechanisms.     

Repair of Extensive Apical Root Resorption Associated with Apical Periodontitis: Radiographic and Histologic Observations after 25 Years

Introduction

Root resorption is a frequent finding in teeth with apical periodontitis. In cases of severe apical periodontitis, root resorption may involve not only cementum but also dentin. Resorbed tooth structures can only be repaired with cementum because stem cells in the periradicular tissues are not capable of differentiating into odontoblasts. This article reports the repair of extensive apical root resorption associated with apical periodontitis 25 years after treatment.

Methods

A 51-year-old man presented with pulp necrosis and symptomatic apical periodontitis in tooth #7. The periapical radiograph showed a large radiolucent periradicular lesion and severe root resorption. Nonsurgical root canal therapy was performed. Twenty-five years after treatment, a crown fracture developed, and the tooth could not be restored. The periapical radiograph revealed complete healing of the previous apical periodontitis lesion and restoration of the resorbed root structure. The tooth was removed and examined histologically.

Results

The apical canal was almost completely filled with a cementumlike tissue with some strands of entrapped vital uninflamed connective tissue. Areas of cementum and dentin resorption in the apical third were repaired by a combination of cellular and acellular cementum to which periodontal ligament fibers were attached.

Conclusions

Root resorption caused by apical periodontitis can be restored almost to its normal structure after adequate nonsurgical root canal treatment that succeeded in controlling infection. The mechanisms behind this process are not clear but probably involve signaling pathways regulating root development, cell-cell and cell-matrix interaction, and morphogens.     

Guided Endodontics: Use of a Sleeveless Guide System on an Upper Premolar with Pulp Canal Obliteration and Apical Periodontitis

Guided endodontics has been used for the treatment of anterior teeth with a successful outcome. This approach is not only limited to anterior teeth because it can also be used for the treatment of premolars and molars. However, in such cases, space may be a limitation because a long bur has to be used in addition to the guide being placed on top of the teeth. The aim of this case report was to present a novel guided endodontics technique using a sleeveless 3-dimensional–printed guide. This design can reduce vertical space, allowing an open view of the tooth and irrigation during drilling. A 46-year-old female patient consulted the endodontic department with intermittent pain around tooth #5. Tooth #5 presented pain upon percussion and responded negative to a cold test. The initial periapical radiograph revealed an apical radiolucency with pulp canal obliteration. Clinically, there was no sinus tract. The tooth was diagnosed with pulp necrosis and symptomatic apical periodontitis. Guided endodontic treatment was performed with a sleeveless 3-dimensional–printed guide and long neck carbide bur with a head diameter of 1 mm to drill a minimally invasive access cavity up to the root canal. A completely healed apical area of tooth #5 was visible after 1 year on periapical radiographs. This technique seems to be a promising alternative in comparison with the conventional guided endodontic guide design for the negotiation of pulp canal obliteration in cases in which vertical space is limited.     

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 endodontics--biologically-based treatment for immature permanent teeth: a case report and review of the literature

Background: A paradigm shift in the treatment of immature, necrotic teeth has occurred with biologically‐based principles and regenerative endodontic protocols replacing traditional ‘apexification’ procedures. Preliminary research suggests that stem and progenitor cells from the pulp and/or periodontium contribute to continued root development when regenerative procedures are followed. Methods: A mandibular premolar tooth with a chronic periapical abscess was irrigated with sodium hypochlorite with minimal instrumentation and then dressed with tri‐antibiotic paste consisting of ciprofloxacin, metronidazole and amoxicillin. At a subsequent visit a blood clot was evoked in the canal by irritating periapical tissues and the canal sealed with mineral trioxide aggregate, glass ionomer cement and composite resin. Results: Resolution of apical periodontitis and the draining sinus, continued root maturation and apical closure occurred over an 18‐month period. The tooth became responsive to pulp sensibility testing. Conclusions: It is important that dentists recognize the potential of regenerative endodontics in the treatment of necrotic, immature teeth. Initial management should involve irrigation with sodium hypochlorite only. Intra‐canal medicaments, such as calcium hydroxide, are contraindicated as they inhibit further root growth. This report uses a variation of the tri‐antibiotic paste currently recommended for regenerative procedures that avoided the discolouration of the crown associated with current protocols. Regenerative endodontics with continued root growth may reduce the risk of fracture and premature tooth loss associated with traditional ‘apexification’ procedures where the root remains thin and weak.     

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.     

Failure of Regenerative Endodontic Procedures: Case Analysis and Subsequent Treatment Options

IntroductionRegenerative endodontic procedures (REPs) are considered effective treatments for immature necrotic permanent teeth, with favorable outcomes. However, failed cases require subsequent treatment. This study aimed to review and analyze failed cases after REPs and suggest a treatment algorithm to aid clinical decision-making.MethodsA total of 111 REP cases were selected that were conducted between 2015 and 2020. Clinical outcomes were assessed based on clinical and radiographic evaluations. The criteria for failure included persistence of clinical signs or symptoms and/or periapical radiolucency showing persistent apical periodontitis. Cases requiring any treatment intervention, including extraction, were also considered failures.ResultsSixteen cases were included as failures. The etiology of pulpal disease was stratified into dental trauma (56%), dens evaginatus (25%), and dental caries (12.5%), with the remaining one case having an undocumented cause. The primary reasons for treatment failure were persistent infection (81.3%) and root resorption (18.7%). The identification time of failure varied, with 6 cases (37.5%) detected in less than 6 months and 10 cases (62.5%) later than 6 months after REPs. Sixteen failed cases received 5 different interventions: second REPs, apexification, conventional root canal treatment, surgical approach, and extraction.ConclusionsInterventions for failed REPs are challenging. Consideration of the treatability of the tooth, accessibility to the canal, and the presence of an apical seat might be key factors in clinical decision-making to obtain a successful outcome.     

Long-term Complications of Previously Successful Regenerative Endodontic Procedures after Orthodontic Movement: A Report of 3 Different Complications after 4, 8, and 11 Years

There is a paucity of literature on late complications of regenerative endodontic procedures. The aim of this article was to report 3 cases of previously successful regenerative endodontic procedures with long-term follow-up that developed different complications after the application of orthodontic forces. In the first case, an 8-year-old female patient received a regenerative endodontic procedure in her previously intruded tooth (tooth no. 21) that had been rendered necrotic after a successful spontaneous repositioning procedure. The 5-year follow-up revealed uneventful healing, continuous root development, dentinal wall thickening, and regaining of pulp vitality for tooth no. 21. Four years later, the patient received orthodontic treatment with mild forces that lasted 2 years. The 11-year follow-up revealed severe external invasive cervical resorption, and the tooth had to be extracted. In the second case, a 6-year-old female patient suffered a lateral luxation injury in tooth no. 11. Six months after the injury, the tooth developed symptoms and discoloration and tested negative in pulp vitality testing. Single-step regenerative endodontic procedures were applied, and successful continuous root development, dentinal wall thickening, and apical closure were achieved at the 3-year follow-up. Two months after the initiation of orthodontic treatment, the tooth developed symptomatic apical periodontitis. Root canal treatment was performed to treat the disease, and the orthodontic treatment was continued. In the third case, a previously published successful regenerative endodontic procedure developed a perforating internal resorption 6 months after the application of orthodontic forces. The internal resorption was arrested with root canal treatment, the resorptive defect was repaired with bioceramic obturation, and the orthodontic treatment plan was modified. Previously successful regenerative cases might develop external invasive cervical resorption, regenerative tissue necrosis, or internal resorption after the application of orthodontic forces. Best practice/evidence-based guidelines on the appropriate orthodontic management of successful regenerative endodontic therapy teeth are lacking. Whenever possible, careful monitoring and partial or complete exclusion off orthodontic treatment might be necessary. In some cases, preventive root canal treatment before the initiation of orthodontic movement might be considered.     

Quantitative Assessment of Intracanal Regenerated Tissues after Regenerative Endodontic Procedures in Mature Teeth Using Magnetic Resonance Imaging: A Randomized Controlled Clinical Trial

IntroductionThe present study quantitatively assessed tissue regeneration after regenerative endodontic procedures (REPs) with 2 different apical preparation sizes in mature teeth using magnetic resonance imaging (MRI).MethodsEighteen maxillary anterior mature necrotic teeth with periapical lesions were selected for the study. The teeth were randomly allocated into 2 groups. Canal preparation was performed using Protaper Next files (Dentsply Sirona, York, PA) until size X3 and X5 in the test and control groups, respectively. REPs were performed, and Biodentine (Septodont, Saint-Maur-des-Fossés, France) was used as the cervical plug material. In both groups, MRI was used to measure the signal intensity (SI) of the regenerated tissue at 3, 6, and 12 months at both the middle and the apical thirds of the canal. The SI between the normal contralateral teeth and each successive interval was compared. Clinical examination, sensibility tests, and digital periapical radiographs were also performed at successive time intervals. Statistical analysis was performed using the Student t test and Cochran test. The level of significance was set at P ≤ .05.ResultsAll 18 teeth were symptom free with healing of the periapical lesions. Regarding the SI measurements, there was no statistically significant difference between the SI of the normal contralateral teeth and that of the regenerated tissues in the treated teeth after a 12-month follow-up. In both groups, more than 60% of the cases regained pulp sensibility after 12 months.ConclusionsVital pulplike tissue could be successfully regenerated in mature teeth using REPs, which was not significantly affected by the size of the apical diameter. MRI could successfully assess this tissue in a quantitative, noninvasive manner.     

Different clinical outcomes following root fractures of adjacent incisors: a case report

AIM: To report different patterns of root fracture healing in adjacent maxillary central incisors with distinct post-treatment outcomes. SUMMARY: To describe the case of a 12-year-old girl who presented with an avulsed coronal fragment of tooth 11 and root fractures in the middle thirds of teeth 11 and 21. Four months after initial treatment, she was referred for specialized endodontic care. Tooth 11 presented no clinical or radiographic signs of pulp breakdown. However a sinus tract was found related to the middle root third of tooth 21, indicating pulp necrosis in the coronal fragment. The coronal fragment was root filled and periapical surgery was performed to remove the apical fragment. Twelve months after the clinical procedures and 16 months after trauma, hard tissue healing was evident in tooth 11 region. Bone healing was also satisfactory in the periapical region of tooth 21. *Even adjacent teeth may display different reaction patterns after trauma. *The prognosis of root fractures is variable and different clinical approach may be required to preserve teeth with fractured roots.     

Periapical cemento-osseous dysplasia in maxillary teeth suggesting apical periodontitis: case report

This article describes the case of a 34-year-old woman whose prosthodontist had referred her for root canal treatment of tooth No. 10, due to an initial diagnosis of apical periodontitis. Although periapical radiolucencies were present, teeth No. 10 and 11 responded positively to pulp vitality tests. A series of periapical radiographs revealed circumscribed periapical radiolucencies on teeth No. 21 and 28, while teeth No. 23, 24, and 27 were associated with mixed radiolucent/radiopaque periapical lesions. All teeth responded to cold stimulus. Based on the clinical and radiographic findings, a diagnosis of periapical cemento-osseous dysplasia was suggested. A re-evaluation 12 months later confirmed this diagnosis. Tooth No. 10 was restored and the patient was scheduled to return for clinical and radiographic follow-up after one year and three years.     

Regenerative Endodontic Procedures in Necrotic Mature Teeth with Periapical Radiolucencies: A Preliminary Randomized Clinical Study

IntroductionThis preliminary study compared clinical and radiographic outcomes of regenerative endodontic procedures (REPs) with that of conventional root canal treatment (CRCT) in necrotic mature teeth with periapical radiolucencies.MethodsFifty-six mature necrotic teeth with large periapical radiolucencies were distributed into 2 groups: group 1, REPs and group 2, CRCT (n = 28/group). Clinical and radiographic follow-up assessments were undertaken up to 12 months. Statistical analysis was performed using the independent samples t test and the chi-square test, and the level of significance was set at P = .05.ResultsWith a follow-up rate of about 73.4% of the total patients for 12 months, favorable clinical and radiographic outcomes were found in 92.3% and 80% in REPs and CRCT groups, respectively, and the difference was not statistically significant (P > .05). Half of the teeth treated with REPs responded to the electric pulp test.ConclusionsRegenerative endodontic procedures have the potential to be used as a treatment option for mature teeth with large periapical radiolucencies.     

Histologic Evaluation of Regenerated Tissues in the Pulp Spaces of Teeth with Mature Roots at the Time of the Regenerative Endodontic Procedures

IntroductionRecently, regenerative endodontic procedures (REPs) have been used to treat mature permanent teeth with apical periodontitis. Although animal studies with regard to histopathological findings after REPs exist, there is a paucity of studies on mature human teeth. As yet, the nature of tissues formed in the root canal of such teeth has not been established. This report presents histologic findings with regard to regenerative tissues in the pulp spaces exposed after dental trauma in human mature maxillary incisor teeth successfully treated with REPs.MethodsA 20-year-old girl was referred to our clinic for the treatment of her central incisors (#8 and #9). The incisors had apical periodontitis. REPs were performed on both maxillary central incisors. Three years 5 months after the initial treatment, the teeth had a horizontal crown fracture and needed a fiber post as well as root canal treatment. Mineral trioxide aggregate was carefully removed, and the tissue that had formed in the canal space was processed for routine histologic and immunohistochemical examination.ResultsHistologic findings of the present case showed that the vital tissue formed in the canal space was fibrous connective tissue that contains bonelike tissue, vascular structures, and inflammation. These histologic findings obtained from mature teeth were similar to the findings of previous reports relating to immature teeth.ConclusionsBased on the present case, the vital tissue formed in the canal space is fibrous connective tissue that contains bonelike tissue, vascular structures, and inflammation. These histologic findings with regard to mature teeth were similar to the findings of previous reports relating to immature teeth.     

Dental Pulp Regeneration Induced by Allogenic Mesenchymal Stromal Cell Transplantation in a Mature Tooth: A Case Report

IntroductionCellular therapy constitutes a new therapeutic alternative in regenerative endodontics. In this case report, we evaluated the capacity of allogeneic mesenchymal stromal cells (MSCs) to induce dental pulp and apical bone regeneration in a tooth previously endodontically treated.MethodsA healthy 55-year-old female patient consulting for swelling and a sinus tract associated with tooth #8 was referred for an endodontic evaluation. Previously, tooth #8 had undergone root canal treatment and apical resection and had no response to thermal or electric pulp testing. Radiographically, tooth #8 showed root canal treatment, a cut apex angle, and periapical radiolucency. The root canal was recleaned and shaped, and calcium hydroxide was used as an interappointment medication. Cryopreserved allogeneic bone marrow MSCs were thawed, expanded, incorporated into preclotted platelet-rich plasma, and implanted into the pulp cavity of tooth #8. The cervical part of the canal was sealed with bioceramic cement and a composite.ResultsAfter 14 months of MSC transplantation, tooth #8 showed sensitivity to cold and electric pulp tests. Radiographic and cone-beam computed tomographic imaging showed signs of increased periapical bone density, healing of the periapical lesion, and almost complete apical remodeling.ConclusionsThis case report shows periodontal bone formation, apex remodeling, and dental pulp regeneration induced by allogeneic MSC transplantation in a mature nonvital tooth. Allogeneic MSCs may constitute a first-line therapy in regenerative endodontics.     

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.     

Assessment of Regaining Pulp Sensibility in Mature Necrotic Teeth Using a Modified Revascularization Technique with Platelet-rich Fibrin: A Clinical Study

Introduction

The aim of the present study was to evaluate the possibility of regaining pulp sensibility in mature necrotic teeth using modified regenerative endodontic procedures by inducing bleeding in root canals and using platelet-rich fibrin (PRF).

下前牙根管再治疗的临床研究

目的:经切缘开髓路径对下颌前牙根管治疗失败的病例进行再治疗,探讨下颌前牙开髓路径提高根管治疗的成功率。方法:临床收集79例下前牙因根管治疗失败后需要再治疗的患牙共计94颗,去除原根充材料,探查是否遗漏根管,采用经切缘开髓路径对患牙进行根管再治疗,治疗前后拍摄X线片,观察对比治疗前后根管的充填情况及下颌前牙根尖病变的愈合情况。结果:94颗患牙中共发现72例下前牙为双根管,其中下颌中切牙为双根管33例,下颌侧切牙为双根管19例,下颌尖牙双根管20例。所有患牙经根管再治疗后根管充填结果满意,患牙根尖病变明显好转。结论:下颌前牙切缘开髓根管路径趋于直线不仅视野良好,且能有效提高复杂根管的发现率及治疗成功率。