Guided Endodontics Modified for Treating Molars by Using an Intracoronal Guide Technique

The aim of this case report was to show the concept of guided endodontics in a maxillary first molar with limited interocclusal space. Guided endodontics involves merging cone-beam computed tomographic imaging and a surface scan of the tooth in order to create a guide to perform a drill path into the seemingly obliterated root canal. In the molar region, the interocclusal space is often too small to accommodate the guide, bur, and handpiece at once, and, therefore, a modified approach is presented. A 52-year-old man was referred because the dentist had failed to localize the distobuccal root canal of a maxillary molar (#3) associated with apical pathosis. After reopening and rubber dam placement, a glide path was established for both the palatal first mesiobuccal root canal and the second mesiobuccal using a size 10 hand file and coronal flaring. Further instrumentation to the working length was achieved by reciprocating file size 25. All 3 canals were temporarily filled with calcium hydroxide. For the distobuccal root canal, guided endodontics was chosen in order to avoid further impairment of the tooth because negotiation of the canal failed even with the use of the operating microscope. Following the merged data obtained from the cone-beam computed tomographic and surface scans, a translucent SICAT Optiguide (SICAT, Bonn, Germany) was constructed containing a sleeve representing the proper direction of a drill path in order to reach the distobuccal root canal. The access cavity was temporarily filled with a composite material made for light-curing. Before light curing, the Optiguide was replaced on the teeth, and a steel pin was pressed through the sleeve and the composite whereby the proper drill path direction was transferred into the composite. After polymerization and removal of the Optiguide and pin from the composite base sleeve, the guided drilling could be performed. This case report is the first on guided access preparation in a molar with pulp canal obliteration and limited interocclusal space. The demand for more interocclusal space was solved by transforming the virtual drill path into a composite-based intracoronal guide. The use of digital technology was essential.     

A New Approach for Minimally Invasive Access to Severely Calcified Anterior Teeth Using the Guided Endodontics Technique

This article describes an endodontic treatment technique performed through a new minimally invasive approach that leads to no tooth damage at the incisal edge and uses cone-beam computed tomographic (CBCT) imaging and 3-dimensional guides. A 26-year-old patient presented with pain in the anterior region of the maxilla and reported having suffered dental trauma 13 years prior. Radiographic examination exhibited no visible root canal on tooth # 9 with a slight thickening in the apical periodontal ligament space. Pulp sensitivity tests produced no response, whereas the percussion test responded positively. CBCT imaging revealed a visible canal space limited to the apical 2-mm section of the root. Guided endodontic access was planned after intraoral scanning of the tooth surface to be used with the CBCT scan. A virtual model was created with the aid of virtual implant software for the surgical access planning in such a way as not to damage the incisal edge of the tooth. The resulting guides were printed. With guides in position over the rubber dam, a mechanical-chemical preparation was performed in the root as soon as the canal was located. Intracanal medication was left for 14 days, after which the root canal was filled gutta-percha and the access cavity sealed. Follow-up was performed 1 year after completion of the treatment. The patient was asymptomatic with periapical tissue within normal limits. The guided endodontic therapy optimized the treatment, having provided a conservative access with no tooth damage at the incisal edge in a safe and predictable way despite the presence of a severely calcified root canal.     

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.     

Guided Endodontics for Managing Severely Calcified Canals

Endodontic treatment of teeth with pulp canal obliteration presents a challenge given the high likelihood of procedural errors and complications during treatment. These drawbacks can be avoided by using a personalized 3-dimensional (3D) guide designed by overlaying a cone-beam computed tomographic scan with an intraoral scan of the patient. This 3D guide enables the clinician to obtain a straight access to the obliterated root canal.This article described guided endodontics in managing 7 severely obliterated teeth using both virtually designed 3D guides and a customized 1-mm-diameter cylindrical bur. This treatment approach was demonstrated to be safe and fast and can be considered as a predictable technique for the location of calcified canals, thus minimizing complications.     

Guided Endodontic Access of Calcified Anterior Teeth

Pulp canal calcification is characterized by the deposition of calcified tissue along the canal walls. As a result, the root canal space can become partially or completely obliterated. Recently, “guided endodontics” has been reported as an alternative solution in cases of partial or completed canal obliteration. Although this technique can enhance minimally invasive access to the calcified canal, it has been shown that the incisal surfaces are often removed during the access of anterior teeth. This report describes 2 cases of guided endodontics using conventional palatal access in calcified anterior teeth and discusses the applicability of this approach in cases of pulp canal calcification with apical periodontitis and acute symptoms. The method demonstrated high reliability and permitted proper root canal disinfection expeditiously, without the unnecessary removal of enamel and dentin in the incisal surface.     

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.     

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.     

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.     

Case Reports in Maxillary Posterior Teeth by Guided Endodontic Access

The localization of partial or completed root canal obliteration is a challenging task in endodontic practice. Recently, guided endodontics has become an alternative solution for those cases. Although this technique has already been used clinically in managing anterior teeth, in this report, we describe 3 complex clinical scenarios of calcified root canals of 1 molar and 2 premolars using guided endodontics. The clinical cases reported here show that technological evolutions should make guided endodontic procedures more widespread because their execution is relatively fast and safe even in the case of the upper molar. Additionally, 12-month clinical follow-up visits showed the effectiveness of the guided endodontic procedures.     

Use of 3-dimensional–Printed Guide in Hemisection and Autotransplantation of a Fusion Tooth: A Case Report

Three-dimensional (3D)-printed guides have been used in endodontics to prepare a conservative access, locate calcified or missing canals, and perform precisive osteotomy in apicoectomy. Here, we present the treatment of a fusion tooth by combining 3D printing technology and endodontic intervention in a 10-year-old patient. The bifid crown of a maxillary right lateral incisor #7 had caused esthetic concerns and malocclusion. Clinical and radiographic examinations showed that #7 is fused with a supernumerary tooth with 2 independent root canals. The fusion involved the entire crown and the coronal and middle roots. Because of financial constraints, a multidisciplinary approach involving endodontic, orthodontic, and prosthodontic treatment was excluded. We hemisectioned the tooth intraorally with a 3D-printed guide, extracted the supernumerary tooth, and transplanted tooth #7 to a position with improved esthetics and occlusion. A 3D-printed tooth replica was used to prepare the recipient site for autotransplantation. At the 6-month follow-up, tooth #7 was diagnosed with pulp necrosis and asymptomatic apical periodontitis. Root canal treatment of tooth #7 was completed, and osseous healing was observed 8 months later. The patient had no clinical symptoms and was satisfied with the outcome 14 months after hemisection and transplantation. The open space between teeth #7 and #8 was closed without orthodontic treatment. We present an alternative option to treat a fusion tooth in young patients who do not opt for other treatment options because of their stage of development or for socio-economic reasons. Techniques in modern endodontics, such as cone-beam computed tomographic imaging and 3D printing, should be adapted when it is beneficial to patients.     

年轻恒牙牙髓血管再生治疗

牙髓血管再生治疗是一种以生物学为基础、生理性取代受损牙齿结构（包括牙本质、牙根以及牙髓牙本质复合体）为目的的治疗技术,是牙髓病学最令人激动的新进展之一。牙髓血管再生治疗是年轻恒牙感染牙髓的治疗新选择,其是通过使用大量的药物冲洗根管并行根管封药控制炎症后,刺激根尖周组织引起出血,使血液进入根管中形成血凝块,然后使用矿物三氧化物凝聚体（MTA）封闭根管口。经过治疗的年轻恒牙能够获得与生理性发育相似的牙根发育。     

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?? Dental pulp revascularization is defined as biologically-based procedures designed to physiogically replace damaged tooth structures including dentin and root structures?? as well as cells of the pulp-dentin complex. Regenerative endodontics is one of the most exciting new developments in endodontics. It is a new treatment option for inflamed pulp in immature permanent teeth. After irrigation and disinfection of the root canal?? the periapical tissues are induced bleeding to fill the canal space to form blood clot. The tooth is then restored with a coronal seal of MTA. The immature tooth could attain continued root development similar to physiological root development after dental pulp revascularization treatment.      

Guided Access Cavity Preparation Using Cost-Effective 3D Printers

IntroductionThe purpose of this in vitro study was to evaluate the accuracy and precision of desktop 3D printers when fabricating stents for guided endodontics.MethodsA stent was designed using planning software for guided endodontic access on a typodont model. Four different 3D printers were used to fabricate an identical stent, one per printer. Each stent was then used to gain access to the artificial endodontic canal on a typodont tooth and was repeated 10 times per stent by the same operator. Each of the accessed typodont teeth were scanned by a reference scanner and then imported into the inspection software. Inspection software used a best-fit alignment to automatically calculate absolute deviation at the base and tip of the bur.ResultsThe mean distances between the planned and actual positions of the bur were low, ranging from 0.31 to 0.68 mm. Statistically significant differences were found among the 4 groups (F_3,36 = 10.67, P < .05). Post hoc comparison revealed that Group Form2 significantly varied from Groups Form3 and Carbon (P < .05 and P < .05, respectively). Group Form3 obtained the most accurate and most precise axial deviations both coronally and apically.ConclusionsAll of the printers tested produced stents for guided access that allowed for a high level of accuracy in obtaining access to the artificial endodontic canal, which would justify the trial of cost-effective 3D printers for guided endodontic access and necessitates further clinical research on teeth with pulp canal obliteration.     

CBCT在根管治疗后疾病诊治中的临床应用研究

目的：评估CBCT影像系统在根管治疗后疾病诊治中的应用。方法：对41颗完成根管治疗的牙齿进行回访,拍摄X线片,进行CBCT扫描重建,对比研究患牙根管治疗前以及回访时病变区域的变化,了解根管治疗后疾病的发生情况,评价根管治疗效果和预后。结果：17例临床术前诊断为根尖周病的病例在CBCT上均可见根尖周组织存在破坏,而X线上仅8例可见根尖区存在破坏。回访病例中根据X线片和CBCT影像诊断为根管治疗后疾病分别为17.03%和39.02%（P〈0.05）。结论：CBCT有利于评估根管治疗程序的可靠性,对根管治疗后疾病诊断及再治疗方案的选择具有重要的临床参考价值,值得在牙髓病诊治中推广应用。     

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.     

Obliteration of pulp canal space after concussion and subluxation: endodontic considerations.

Concussion and subluxation injuries to permanent teeth lead to obliteration of the pulp canal space in 3% to 11% of cases, depending on the severity of the injury and the developmental stage of the tooth. Obliteration of the pulp canal space may make root canal treatment necessary because of the development of apical periodontitis or for cosmetic reasons. If carefully executed, root canal treatment in teeth with an obliterated pulp canal space is highly successful and may act as a basis for internal bleaching.     

Endodontic applications of 3D printing

Computer‐aided design (CAD) and computer‐aided manufacturing (CAM) technologies can leverage cone beam computed tomography data for production of objects used in surgical and nonsurgical endodontics and in educational settings. The aim of this article was to review all current applications of 3D printing in endodontics and to speculate upon future directions for research and clinical use within the specialty. A literature search of PubMed, Ovid and Scopus was conducted using the following terms: stereolithography, 3D printing, computer aided rapid prototyping, surgical guide, guided endodontic surgery, guided endodontic access, additive manufacturing, rapid prototyping, autotransplantation rapid prototyping, CAD, CAM. Inclusion criteria were articles in the English language documenting endodontic applications of 3D printing. Fifty‐one articles met inclusion criteria and were utilized. The endodontic literature on 3D printing is generally limited to case reports and pre‐clinical studies. Documented solutions to endodontic challenges include: guided access with pulp canal obliteration, applications in autotransplantation, pre‐surgical planning and educational modelling and accurate location of osteotomy perforation sites. Acquisition of technical expertise and equipment within endodontic practices present formidable obstacles to widespread deployment within the endodontic specialty. As knowledge advances, endodontic postgraduate programmes should consider implementing 3D printing into their curriculums. Future research directions should include clinical outcomes assessments of treatments employing 3D printed objects.     

Optimisation of a guided endodontics protocol for removal of fibre‐reinforced posts

This paper demonstrates the usefulness of endodontic guides for the removal of fibre posts. A 36‐year‐old man consulted for retreatment of a maxillary first molar presenting a periapical pathology. This tooth revealed a composite reconstruction together with a glass‐fibre post in the palatal root canal. To assist removal, use of an endodontic 3D‐printed guide was indicated. A cone beam computed tomography examination and an optical impression were made to produce a tooth‐supported guide by means of implant planning software (Blue Sky Plan, Blue Sky Bio^®). The software enabled definition of a drilling pathway, which was transferred clinically using a resin template together with a sleeve and a 0.75‐mm drill. The drill was guided as far as the gutta‐percha situated in the apical third, limiting any risk of impairment or perforation.     

根管治疗期间疼痛问题的临床观察

目的 探讨根管治疗期间疼痛发生的原因。方法 对330例临床病人366颗根管治疗的牙齿进行临床观察。结果37颗牙（10.1％）发生了不同程度的根管治疗术后疼痛,其中死髓牙、后牙、根尖阴影小的牙和近期有过疼痛史的牙齿发生疼痛的比例较高。结论 与根管治疗术后疼痛发生关系较为密切的因素有牙髓坏死、牙位、根尖阴影和疼痛史等,确切原因尚有待于进一步研究。     

Comprehensive therapy of a fusion between a mandibular lateral incisor and supernumerary tooth: case report

The term fusion is used to define a developmental anomaly characterised by the union of two adjacent teeth. In the case reported here, clinical and radiographic examinations suggested a unilateral fusion between the mandibular left permanent incisor and a super-numerary tooth. Radiographs showed that the fused teeth had two distinct pulp chambers and canals. A diagnosis of chronic periapical abscess of the supernumerary tooth was made. Before root canal therapy, a periodontal surgical procedure was performed to section the central incisor and its fused supernumerary. Also, odontoplasty was performed on the roots, to establish an anatomy consistent with a normal central incisor. Later, the chronic apical abscess on the supernumerary tooth was instrumented chemo-mechanically, root canal filling was performed and an anterior composite resin restoration was placed. The patient was evaluated for one year after root canal therapy. The tooth was asymptomatic, not exhibiting any pathological root resorption or alveolar resorption, and the anterior composite restoration was intact. Instead of extracting the supernumerary tooth, the application of endodontic, periodontal, and restorative procedures proved to be an alternative treatment.