Management of separated instruments using a loop technique: Case series with a rapid review

Fracture of endodontic instruments in the canal is an unfortunate occurrence that may hinder the root canal procedure and negatively impact the treatment outcome. This fragmented instrument present inside the root canal can prevent proper preparation of the root canal space. Overall endodontic prognosis following instrument separation depends on the stage and degree of canal preparation and disinfection at the time of the instrument fracture. Instrument fracture caused by iatrogenic error can occur due to repeated use of instruments, improper technique, lack of lubrication, insufficient knowledge and skills, and use of inappropriate instruments. Management of instrument fracture includes techniques such as bypass or retrieval. This case report describes endodontic bypassing with a separated instrument in a curved canal. Endodontic treatment aims to clean, shape, and obturate the root canal system to prevent or treat apical periodontitis.[1] However, procedural errors such as instrument separation can occur, complicating the treatment process and potentially jeopardizing the outcome. The separation of endodontic instruments within the root canal is a common and challenging problem that can hinder adequate canal cleaning and shaping, leading to potential treatment failure.[2,3] Instrument separation is frequently attributed to factors such as repeated usage, improper technique, insufficient lubrication, and the intrinsic material characteristics of the instruments themselves. The incidence of separated instruments varies depending on the type of instrument and the clinician’s experience. NiTi (Nickel-titanium) rotary instruments, while highly flexible and efficient, are more prone to fracture compared to stainless steel instruments due to their unique mechanical properties.[4,5] When an instrument fractures inside a root canal, it can block access to the apical portion of the canal, preventing thorough cleaning and disinfection. This can lead to persistent infection and failure of the endodontic treatment. The management of separated instruments includes techniques such as bypassing or retrieval. Bypassing involves negotiating a small instrument around the separated fragment to achieve patency and continue with the root canal preparation, whereas retrieval focuses on removing the fragment from the canal entirely.[6-8] This case report describes the successful management of a separated endodontic instrument in a curved canal of a maxillary molar using a bypassing technique. The case highlights the importance of clinical skill, appropriate technique, and the use of advanced tools to overcome the challenges posed by instrument separation. Through this report, we aim to provide insights into the practical application of bypassing techniques in endodontic practice and emphasize the need for continuous training and knowledge enhancement among endodontists.[9]

Instrument separation during root canal treatment can hinder effective cleaning and shaping, making reliable retrieval techniques essential. Endoscopic visualization might aid in instrument removal procedures offering direct magnification of root canal anatomy. This ex vivo study evaluated the success rate and procedure time of three instrument retrieval techniques - Masserann, microsonic, and loop techniques - under the visualization of dental operation microscope (DOM) assisted by an endoscope. Sixty extracted human mandibular single-rooted teeth with simulated fractures were assigned to the Masserann, microsonic, or ultrasonic with loop techniques (n = 20/group), each performed under endoscopic visualization alongside DOM. The success rate of instrument removal and procedure time were recorded. Complications, such as root perforation, apical extrusion and secondary fracture, were recorded. Statistical analysis was conducted using Pearson χ2 and Kruskal-Wallis tests with 5% significance threshold. Success rates for the microsonic, Masserann, and ultrasonic with loop techniques were 80%, 70%, and 80%, respectively (p > 0.05). The average procedure times were 13.02 min for the microsonic technique, 17.25 min for the Masserann technique, and 17 min for the ultrasonic with loop technique (p > 0.05). The Masserann technique demonstrated a higher complication rate, with two cases each of perforation and apical extrusion, whereas no secondary fractures occurred in any group. Conclusively, the microsonic technique showed the highest success rate with the shortest retrieval time, indicating its efficiency and suitability for instrument removal from root canals, particularly when combined with enhanced visualization through endoscopy.

The most common endodontic mishap that eventually occurs during any root canal therapy is the separation of instrument inside the canal. The separated instrument influences the final outcome and prognosis of the root canal therapy. The clinician is confronted with a few options when considering this situation. These options can include leaving the fragment or incorporating the fragment to form part of the final obturation or removal from the root canal. Once the decision is made to remove the separated instrument, the clinician must realize that the procedure can be one of the most difficult treatments to attempt. This case report describes retrieval of separated instrument in the middle to apical third area using ultrasonic tips and braiding technique.

Fractured endodontic instruments complicate root canal treatment by obstructing cleaning and shaping. The loop technique is a widely used retrieval method, but the optimal depth of dentin troughing required for successful retrieval remains unclear. Insufficient troughing can lead to failed attempts, wasted materials, and operator fatigue, whereas excessive troughing may increase chair side time, cause dentin loss, and lead to iatrogenic errors. The aim of the study was to evaluate the depth of dentin troughing required for successful retrieval of fractured endodontic instruments using the loop technique and to analyze secondary outcomes, including retrieval time and success rates. This cross-sectional in vivo study included 60 teeth with fractured instruments, comprising 39 rotary and 21 hand instruments. The procedure was performed using high magnification, with a modified Gates Glidden drill and an ISO 25 sonic spreader to create a staging platform and expose the file head. The loop technique, employing a 27-gauge syringe and 0.02 mm Stainless steel wire, was used for retrieval. Troughing depth and retrieval time were recorded. Measurements were taken using a stereo microscope and analyzed with ImageJ software. Data obtained were statistically analyzed using ANOVA, paired samples test. P < 0.05 was considered statistically significant. The mean troughing depth was significantly greater for rotary instruments (0.42 mm ± 0.25 mm) than for hand instruments (0.28 mm ± 0.18 mm). The overall success rate was 98.3%, with no significant difference between rotary (97.4%) and hand instruments (100%). Retrieval time was significantly longer for rotary instruments (46.2 ± 3.2 min) than for hand instruments (32.4 ± 2.4 min, P < 0.05). Rotary instruments require deeper troughing and longer retrieval times compared to hand instruments. This study provides evidence-based guidance for optimizing fractured instrument retrieval while preserving tooth structure and minimizing procedural risks.

Separated endodontics instruments and high-density obturating materials produce metal artifacts on cone-beam computed tomography (CBCT) scans. This study evaluated a novel methodology to detect separated instruments using artifact suppression and color map algorithms with CBCT post-processing software and compared with periapical radiographs (PRs). Endodontic instruments were incorporated into 168 root canals filled with four sealers. Additionally, 40 root canals were only filled, serving as control. CBCT scans were acquired in PreXion-3D-Elite, and digital PRs were taken in distoradial, mesioradial, orthoradial, and proximal directions. The treated teeth were analyzed using an artifact suppression algorithm combined with a color map algorithm. The separated instruments appear in the color map with larger expansion in red to allow identification. This map provides valuable information by showing dynamic visualization toward the point of expansion of the high-density object, hence suggesting a separated instrument. The chi-square test was used to compare the separated instruments among the imaging methods. Bonferroni correction was used for multiple comparisons. Statistical significance was considered P < 0.05. Overall, CBCT performed significantly better than PRs (P < 0.001) in detecting separated instruments. PR was influenced by all the variables studied (P < 0.05). The artifact suppression and color map algorithms, combined with dynamic navigation, effectively identified separated instrument fragments in all the root canal fillings, regardless of filling material, image view, or root canal. Only 32.3% of the root canal fillings viewed by PR detected separated instrument fragments. This method seems to be useful in the resolution of the problem of viewing separated instruments with CBCT post-processing software.

Instrument separation is one of the most common procedural errors that may occur during endodontic treatment. A separated instrument can create an obstruction in the root canal which can hinder the cleaning and shaping procedures. If an instrument separation takes place, an attempt should be made to retrieve the instrument and if retrieval is not possible, the instrument should be bypassed. Nickel–titanium (NiTi) instruments have several advantages, such as superelasticity and shape memory, which prompted their use in endodontics. Due to these characteristics, NiTi instruments have shown to preserve the original anatomy and shape of the root canal. However, the disadvantage is that they fail to show signs of fatigue prior to fracture unlike stainless instruments. This article describes a case report showing the successful use of a modified tube, loop and file technique for the retrieval of two separated instruments, from a maxillary lateral incisor of a 14-year-old male patient.

Aim: This study aims to evaluate the retrieval outcome of the separated endodontic instrument by endodontic board residents. Materials and Methods: Records of 450 endodontic cases with separated endodontic instruments treated by endodontic Saudi board residents were randomly selected. The evaluation was based on the tooth type, type of fractured instrument, incidence and anatomical location in the root canal and if the instrument was retrieved, bypassed, or left. Data were statistically analyzed using IBM-SPSS.22. Results: A total of 84 (19%) separated instruments were identified. Thirty-four cases (7.55%) with separated instruments out of the total evaluated cases were done by residents. The incidence between hand stainless steel and nickel-titanium instruments was statistically significant (P Conclusions: Regardless of little experience of the endodontic residents, they were successfully managed to remove or bypass most of the separated instruments. Ultrasonic device was very helpful in removing the separated instrument.

ABSTRACTThere are several reasons for a root canal therapy to be unsuccessful. One of the causes for endodontic failure is instrument separation. As a consequence of fracture, access to the apical portion of the root canal is obstructed, leading to improper disinfection. The retrieval of separated instrument followed by obturation to the working length is the treatment option. Many factors can make retrieval difficult. In such cases, management can be done even by bypassing the separated instrument. Another factor for endodontic failure is underobturation. It may be due to block or ledge in the apical third of the canal. Proper instrumentation with frequent confirmation of apical patency during instrumentation can prevent formation of ledge. The inability to treat all the canals is the other cause leading to endodontic failure. Bacteria residing in these canals lead to the persistence of symptoms. Proper evaluation of the radiograph with proper deroofing can prevent chances for missed canals. Combination of all these factors can make retreatment difficult. This case report discusses two endodontic failure cases. In the first case, a premolar tooth with separated instrument and incomplete obturation was treated by retrieval of separated instrument and the obturation of both canals to working length was done. The second one was a molar tooth which had a missed canal, a separated instrument, and an incomplete obturation. Missed canal was negotiated and the fractured instrument was bypassed and root canal was obturated.How to cite this articleKumar MM, Nair KR, Geetha P, Nazar F, Alexander RN, Raj A. Management of Endodontic Failure. Cons Dent Endod J 2017;2(2):60-64.

Cone-beam Computed Tomography Volumetric Analysis and Comparison of Dentin Structure Loss after Retrieval of Separated Instrument by Using Ultrasonic EMS and ProUltra Tips

Background: Instrument separation is a frequent issue in root canals, often complicated by intriguing anatomical variations that make treatment more challenging. These variations in canal structure can lead to various iatrogenic complications, such as missed canals, instrument separation, gouging, perforation, and overextension of obturation materials. One such complication is instrument breakage, which can disrupt the cleaning and shaping processes and potentially cause pain or discomfort. Materials and Methods: The present systematic review was conducted following PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. The present systematic review aimed to identify all clinical trials focused on the removal of separated instruments from endodontic canals using an endodontic surgical approach. Results: A total of 21 studies were included, reporting 22 cases involving surgical approaches for separated instrument removal. Conclusions: The analysis of available evidence, although prim Information added.arily based on clinical cases and case series, emphasizes that surgical approaches for removing separated endodontic instruments are a viable therapeutic option when non-surgical treatments are ineffective or not feasible. Techniques such as apicoectomy, intentional replantation, surgical removal, and the technique provide innovative, customized solutions for addressing complications related to separated instruments, showing favorable clinical and radiographic success rates in follow-up assessments.

Instrument separation during endodontic therapy is a frequent accident with rotary instruments being more likely to separate than manual ones. The treatment of cases with a separated instrument can be either conservative or surgical. A conservative approach involves the following treatment choices: a) bypass of the fragment, b) removal of the fragment, c) instrumentation and obturation coronally to the fragment. Concerning the removal of a separated instrument, a variety of techniques and systems have been developed. Ultrasonics, in combination with the operative microscope constitute the most effective and reliable tools for removing a separated endodontic instrument from a root canal. The likelihood of successful removal depends on: the level of separation (coronal, middle or apical third); location in relation to the root canal curvature; the type of separated instrument; its length; the degree of canal curvature and the tooth type. Several complications may occur during the management of a separated instrument: separation of the ultrasonic tip or file used for bypassing or removing the instrument; further separation of the fragment; perforation; ledge; extrusion of the file into periapical tissues; tooth weakening due to dentin removal, as well as excessive temperature rise in periodontal tissues. Prognosis for a tooth retaining a separated instrument depends on the presence of a periapical lesion, the microbial load of the root canal during the time of separation and the quality of the obturation.

Objective: We describe how to assess the degree of canal curvature and manage a separated instrument using an ultrasonic device. Case Report: A 24-year-old female was referred by a general dentist for an accidentally separated Protaper F2 instrument. The mesiobuccal canal was enlarged and the separated instrument could be visualized via the dental operating microscope. Preoperative radiography revealed a separated endodontic instrument at the middle to apical third of the mesiobuccal canal. Mesiobuccal canal curvature measured 66°. After rubber dam isolation, a specific ultrasonic tip and the dental operating microscope were used to gain access around the separated instrument until it loosened. The separated instrument was agitated and accidentally sucked into the high-speed suction device. The canal was evaluated with higher magnification via the dental operating microscope and postoperative radiographs were taken to confirm removal. Conclusion: Retrieval of a separated instrument in the curved canal is effective using a specific ultrasonic device plus a dental operating microscope

Instrument retrieval from maxillary central incisor: A case report - IJCE- Print ISSN No: - 2581-9534 Online ISSN No:- 2581-8988 Article DOI No:- 10.18231/2456-8953.2018.0007, IP Indian Journal of Conservative and Endodontics-IP Indian J Conserv Endod

This clinical report presents a new method for retrieving separated instruments from the root canal with minimally invasive procedures. The presence of separated instrument in root canal may interfere in the endodontic treatment prognosis. There are several recommended methods to retrieve separated instruments, but some are difficult in clinically practice. This study describes two cases of separated instrument removal from the root canal using a stainless-steel prepared needle associated with a K-file. Case 1 presented a fractured gutta-percha condenser within the mandibular second premolar, it was separated during incorrect intracanal medication calcium hydroxide placement. Case 2 had a fractured sewing needle within the upper central incisor that the patient used to remove food debris from the root canal. After cervical preparation, the fractured instruments were fitted inside a prepared needle and then an endodontic instrument (#25 K-file) was adapted with clockwise turning motion between the needle inner wall and the fragment. The endodontic or atypical nonendodontic separated instrument may be easily pull on of the root canal using a single and low cost device. The methods for retrieving separated instruments from root canal are difficult and destructive procedures. The present case describes a simple method to solve this problem.

Background: Gutta-percha is commonly used in endodontic therapy for obturating root canals after cleaning and shaping procedures. Warm and cold gutta-percha techniques are two common methods employed for obturation, each with its own advantages and limitations. Materials and Methods: Twenty extracted human teeth with single-rooted canals were selected and divided into two groups: warm gutta-percha obturation and cold gutta-percha obturation. In the warm gutta-percha group, gutta-percha was heated to a predetermined temperature using a warm gutta-percha heating device and injected into the root canal using a heated carrier. In the cold gutta-percha group, gutta-percha was applied directly to the root canal without prior heating. Root canal obturation quality was assessed using radiographic imaging to evaluate the presence of voids, completeness of obturation, and adaptation to the canal walls. Micro-computed tomography (micro-CT) analysis was also performed to quantify the volume of obturating material and assess the three-dimensional distribution of gutta-percha within the root canal space. Results: Both warm and cold gutta-percha techniques demonstrated effective obturation of root canals, with comparable outcomes in terms of void formation, completeness of obturation, and adaptation to canal walls. However, micro-CT analysis revealed differences in the volume and distribution of gutta-percha within the root canal space. Warm gutta-percha obturation exhibited more uniform distribution of gutta-percha material and higher volumetric filling compared to cold gutta-percha obturation. Additionally, the warm gutta-percha technique demonstrated superior flowability and adaptation to irregularities within the root canal system. Conclusion: In this in vitro study, warm gutta-percha obturation demonstrated advantages over cold gutta-percha obturation in terms of volumetric filling, distribution within the root canal space, and adaptation to canal irregularities.