Management of separated endodontic instruments: case reports.

Successful management of separated endodontic instruments is difficult, but several techniques are available for the retrieval of a separated instrument (SI). An appropriate treatment plan depends on various factors, including the anatomy and location of the tooth; the size, type, and location of the SI; and the skill of the clinician. However, the selection of the most appropriate management technique based on these factors can be a challenging decision that directly influences the success of the procedure. This article presents 4 symptomatic cases of SIs managed with various modalities as well as 1-year clinical and radiographic follow-up results. The management techniques applied in these cases included the use of ultrasonic tips, the wire loop method, safe-sided H-files, the braiding technique, and bypassing of the file. The medical history of the patients was noncontributory except for a single patient who had type 2 diabetes mellitus, which might have delayed healing. After instrument retrieval, the patients were evaluated clinically for relief of signs and symptoms as well as for their responses to various tests such as percussion, palpation, and tooth mobility. Radiographic evaluation at the 12-month follow-up was used to determine the periapical index. The clinical and radiographic results and patient-reported outcomes were satisfactory in all cases. The 4 cases presented demonstrate that the keys to successful management of an SI are understanding the factors that influence the case and selecting an appropriate therapeutic technique.

Do separated instruments affect pH levels when using calcium hydroxide as intracanal dressing?

BACKGROUND: The aim of this study was to evaluate the effect of intracanal separated instruments with different lenghts on periapical pH levels using calcium hydroxide (CH) as an intracanal medicament. MATERIALS AND METHODS: In total, 60 teeth were used. Following root canal preparation, teeth were divided into four groups (n = 15). In Group 1, 2 mm and in Group 2, 4 mm weakened from the tip of Revo-S NiTi SC2 (Micro-Mega, Besancon, France) instruments were separated in the apical portion of root canals. In Group 3, there was no separated instrument. CH paste was placed in the first three groups. In Group 4, there was no separated instrument or CH paste. Teeth were placed in containers with deionized distilled water. After 1 h and 1, 2, 7, 15, and 30 days, the pH of the solution was measured. RESULTS: At 1 h, Group 3 showed a significantly higher pH than Groups 1 (2 mm) and 2 (4 mm; P < 0.05). At the same time point, Group 1 (2 mm) showed a higher pH than Group 2 (4 mm) without significance. At 1, 2, 7, 15, and 30 days, Group 2 (4 mm) showed a significantly lower pH than Groups 1 (2 mm) and 3 (P < 0.05). At the same time points, Group 1 (2 mm) showed a lower pH than Group 3 without significance. CONCLUSIONS: Separated instrument may affect the rise in periapical pH level when using CH as the intracanal dressing. Therefore, 4 mm of separated instrument in the apical third showed a significant effect.

Management of an Intracanal Separated Instrument in the Lower Right First Molar: A Case Report.

Separating an endodontic instrument is one of the most frequent errors during a root canal treatment. If endodontic instruments get separated, it could hinder disinfection and prevent access to the apical portion of the root. It compromises the success of the treatment by impeding the proper debris removal from the canal. But now that techniques and tools have advanced, it is feasible to remove a separated instrument from the root canal successfully. This case report presents the management of a separated instrument, demonstrating the successful removal of the separated instrument.

Bridging the Gap between Endodontic Failure and Success: A Case Report on Intentional Replantation.

This case report describes a case of intention replantation in a 15-year-old patient with a mandibular permanent right second molar that had undergone root canal treatment previously. The tooth was tender on percussion. Radiographic evaluation showed the presence of a separated instrument and periapical radiolucency. The surgical procedure was performed under local anesthesia, and the tooth was extracted. After cleaning and disinfecting the root canal system, the tooth was reimplanted, and the socket was filled with a mixture of bone graft material and a growth factor. A stainless steel crown was then placed to protect the tooth. A follow-up examination was performed after 12 months. The clinical and radiographic examinations revealed a well-healing periapical lesion with no signs of infection. The patient was asymptomatic, and the tooth was functional. The results of this case indicate that intentional replantation can lead to a favorable outcome.

Endodontic Clinical Outcome after Separated Instrument Removal Using a Spinal Needle Technique: A Retrospective Study of Thirty Years of Clinical Experience.

INTRODUCTION: Current methods for the removal of separated endodontic instruments (RSI) are not predictable. METHODS: The primary outcome of this retrospective study was to assess the clinical and radiographic success (CRS) of teeth in case of RSI after a 5-year follow-up. Secondary outcomes were to evaluate (1) the effectiveness in RSI and (2) the risk of root fracture after RSI. The study protocol was registered at ClinicalTrials.gov (ID: NCT05128266). The patients were treated by the same endodontist between January 1991 and December 2019. The RSI was performed under the operative microscope as follows: first, the dentine surrounding the coronal part of the broken instrument was selectively removed by using a small ultrasonic tip to loosen the fragment; then, a modified spinal needle was used to catch and remove the instrument. The 1-, 3-, 5-, and >5-year CRS were recorded. Logistic regression analysis was performed to determine independent predictors of failure (ie, tooth number, type of root canal, shape of the root canal, type of broken instrument, apicocoronal level of the separated instrument, presence of periapical lesions, and root perforations). RESULTS: A total of 158 teeth were included in this study. Finally, 131 instruments underwent RSI (82.9%). RSI was an independent predictor of CRS after 1-year of treatment (odds ratio: 58.3; 95% confidence interval: 27.42-95.73, P < .05). At the 5-year follow-up, only 10 of 131 teeth (7.6%) failed. All failures were caused by root fracture (10/10) (χ2 test, P < .05). Separated instruments located in the apical third of the root were more difficult to remove (13/49 cases, 26.5%; χ2 test, P < .05). CONCLUSIONS: The proposed technique can achieve excellent effectiveness in RSI, can achieve a high CRS rate when a periapical lesion is present, is not associated to a significant increase in root fracture incidence, and should be performed with the help of an operative microscope.

The Good Old Masserann Technique for the Retrieval of a Separated Instrument: An Endodontic Challenge.

Instrument separation is one of the most upsetting endodontic errors, and it can occur at any time during root canal surgery. A broken file causes a metallic restriction in the root canal and makes it difficult to clean and shape the instrument effectively, thereby making the prognosis questionable. Hence, such a fragment should be properly retrieved when it becomes difficult to bypass it. A variety of techniques and tools are utilized for instrument recovery; however, most of them are expensive, difficult to master, and technique-sensitive. One such tool for orthograde removal of intracanal metallic obstacles is the Masserann kit. We discuss a case involving file removal from the maxillary premolar by using the Masserann technique.

Retrieval of Separated Intracanal Endodontic Instruments: A Series of Four Case Reports.

The separation of an endodontic instrument during a root canal procedure is one of the most common endodontic mishaps. Separation of endodontic instruments may block access to the apical portion of the root and hamper the disinfection process. It obstructs the appropriate debridement of the canal apical to the fragment, jeopardizing the treatment's outcome. However, due to the advancements in the methods and armamentarium, the effective retrieval of a separated instrument (SI) from the root canal has become possible. This paper includes a case series of management of separated instruments whereby SI was successfully removed in four cases. The instruments were separated intracanal at various levels in the middle and apical third of maxillary and mandibular molar teeth. The level of separation was located, staging performed, and SI was removed using an ultrasonic device under magnification. Removal of the SI was followed by obturation till the entire working length and subsequent post-endodontic restoration. Patient satisfaction with treatment outcomes in all cases was good. Case evaluation, good armamentarium, adequate knowledge along with good clinical skills and experience aid in the successful retrieval of separated instruments. Removal of the instrument without further damage to radicular dentin is important to maintain the integrity of the tooth.

Management of Separated Instruments Extruded into the Maxillary Sinus and Soft Tissue: a Case Series.

Extrusion of separated endodontic instruments is a frustrating complication that can occur during root canal treatment and is difficult to handle. This report aimed to introduce different methods to retrieve such separated instruments through three cases with different locations of fragments. Fragments extruded completely into the maxillary sinus, partially into the maxillary sinus and lying in the soft tissue were retrieved using a lateral window approach, ultrasonic method and minimally invasive surgery, respectively. These methods can be recommended for retrieving fragments in certain cases.

Factors Affecting the Removal Time of Separated Instruments.

INTRODUCTION: Separated endodontic instruments may adversely affect the outcome of endodontic treatment. The combination of ultrasonic techniques and dental operating microscopes appears to be effective in the removal of separated instruments compared with more randomized techniques. This study evaluated the roles of root canal curvature and separated instrument length on the time needed to loosen and retrieve the instrument fragments. METHODS: The retrieval procedures of 128 separated instruments referred to a private endodontic practice for retreatment by general practitioners were evaluated in patients who were monitored for a minimum of 6 months. Preoperative cone-beam computed tomographic images were used to measure separated instrument lengths in relation to the degrees of canal curvatures. Ultrasonic instruments were used in the initial phase to remove the tooth structure and to loosen the fractured instrument. In the second phase, ultrasonic instruments, wire loops, or XP Shapers (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) were used for fragment removal. The time periods for all procedures were recorded. Statistical analysis was completed applying log-normal regression, structural equation modeling, and linear regression using Stata Version 14.2 software (StataCorp LLC, College Station, TX). RESULTS: All separated instruments were successfully retrieved. Using the protocol in this study, 89.8% of the instruments were removed using ultrasonic instruments alone with a mean time of 221 seconds. The instrument removal time was dependent on both the instrument length and the root canal curvature. Additionally, preparation times were proportionately longer with increasing separated instrument lengths when the loop device was required. CONCLUSIONS: The preparation phase appears to have an important role in the retrieval of separated instruments. Preparation times for both non-loop and loop groups demonstrate that length and curvature are independent predictors of the log-transformed time. Generally, procedure times were extended with increasing file lengths and higher degrees of canal curvature.

The time taken for retrieval of separated instrument and the change in root canal volume after two different techniques using CBCT: An in-vitro study.

Introduction: Retrieval of separated instrument from a root canal may lead to increased dentin loss and prolonged treatment time. Aim: The aim of this study was to evaluate the retrieval time and increase in root canal volume after instrument retrieval with two retrieval techniques under dental operating microscope. Materials and Methods: Forty extracted human mandibular molars with 30°-40° mesiobuccal root canal curvature were selected based on cone-beam computed tomography (CBCT) and divided into two groups (n = 20 each). Group 1: Terauchi group (Terauchi ultrasonic tips) and Group 2: Satelec group (Satelec ET25 ultrasonic tip) based on the retrieval technique. Groups 1 and 2 were further divided into two subgroups (n = 10 each) based on the size of the separated instrument; Groups 1a and 2a with ProTaper Gold (PTG) F1 and Groups 1b and 2b with PTG F2. The time taken for retrieval was calculated and increase in root canal volume was evaluated using CBCT. Results were statistically analysed with paired t-test and post hoc analysis by Tukey's HSD test. Results: All separated instruments were successfully retrieved. The mean time for instrument retrieval was lower in Terauchi group than in the Satelec group (P > 0.05) but not significantly. The mean increase in total root canal volume post-retrieval as well as the mean volume corresponding to the coronal part of the separated instrument was significantly lower in Terauchi group than in Satelec group (P < 0.05). Conclusion: Terauchi ultrasonic instruments resulted in reduced instrument retrieval time with lower loss of root dentin.

Effectiveness of different irrigation systems in the presence of intracanal-separated file.

The aim of this study was to evaluate conventional syringe irrigation and three different irrigant activation techniques' effectiveness for smear layer removal in the absence and presence of intracanal-separated file (SF) fragment. Mandibular anterior teeth (160 total) with single canal were used and each root canal preparation was finished with the ProTaper Universal F1. The samples were randomly divided into eight equal groups with n = 20 in each group. The Protaper Universal F3 file was used to simulate intracanal file separation in four groups. To remove the smear layer, final irrigation for each group was performed with conventional syringe irrigation (CSI), EndoActivator, Vibringe, and passive ultrasonic irrigation (PUI). The roots were divided into two longitudinal parts and evaluated with scanning electron microscopy, and two observers scored smear layers at 1, 2, and 3 mm away from the minor foramen. The data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests (p < .05). PUI significantly removed the smear layer better at all levels than other nonseparated file groups (p < .05). In the presence of intracanal SF, PUI had the most efficiency loss. Sonic techniques and CSI revealed statistically better smear layer removal efficiency than PUI at 3 mm level in the presence of SF (p < .05). The intragroup score analysis at all levels revealed that there were less smear layers at 3 mm than at 1 mm in all SF groups (p < .001). As a conclusion, sonic/ultrasonic methods did not yield better irrigant by-passing than CSI in the presence of intracanal SF.

Antimicrobial Photodynamic Therapy associated with long term success in endodontic treatment with separated instruments: A case report.

This paper describes a case with a 5- year follow-up of Antimicrobial Photodynamic Therapy (aPDT) associated with long-term success in endodontic treatment in a tooth with separated instruments. The patient presented with a tooth exhibiting a periapical lesion, slight swelling, and severe pain. A radiograph revealed the presence of two separated files in the middle and apical thirds of the mesial root on a lower first molar. Attempts at bypassing were not successful. In the mesial root, instrumentation was limited to the coronal ends of the separated instruments. The apical patency could not be achieved due to the blockage of the separated files. aPDT was performed in two visits, at a 660-nm wavelength and 100 mW of power, for 90 s to a total energy of 9.0 Joules. Methylene blue solution was used as photosensitizer at concentration of 0005%. A 300-µm light diffusor was coupled to the diode laser and was inserted into the root canal 2 mm short of WL, where it was set to allow better diffusion of light. Each root canal was sealed with gutta-percha by warm vertical compaction and Pulp Canal Sealer™. After 5 years of follow-up, clear evidence of remineralization of the radiolucency and bone healing was observed. This case report suggests that the addition of aPDT to conventional endodontic treatment improved microbial disinfection leading to a successful long-term outcome.

3P's in Retreatment Endodontics-An Often Forgotten Virtue.

Separation of instrument in the root canal is a common mishap that occurs during the cleaning and shaping procedure. So many different methods have been developed to retrieve fractured instruments from root canal. Separated instrument leads to incomplete cleaning of root canal and eventually causes posttreatment disease. For successful completion of treatment, a separated instrument must be retrieved and if not, a bypass must be attempted. This article presents four cases requiring removal of separated instruments from the root canal. All four cases were successfully treated by conservative means of instrument retrieval by using two different techniques.

Diagnostic Value of Cone-Beam Computed Tomography and Digital Periapical Radiography in Detection of Separated Instruments.

Introduction: File Fracture is one of the most common problems during root canal treatment which can affect treatment procedure and prognosis, so it is important to diagnose and prevent it. The aim of this study was to evaluate and compare the diagnostic value of cone-beam computed tomography (CBCT) and digital periapical radiography for detection of separated instrument retained inside the canal. Methods and Materials: Ninety single-rooted extracted human teeth were selected and randomly divided into 3 groups (n=30). Group 1, separated file #10 at the 2-mm apical third of the root canal; group 2, separated file #35 at the 2-mm apical third of the root canal; and group 3, without a broken file (control group). The teeth were instrumented to size #30 and were shaped to size #55 and then the canals were obturated up to separated instrument, or the working length for the teeth without a separated instrument, with lateral condensation technique. After that all teeth were placed in dry skull, digital radiography and CBCT was taken. After data collection, data was analyzed using SPSS software by means of sensitivity, specificity, positive and negative predictive values, and frequency tables. Results: Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of digital periapical radiography in detection of a fractured file #10 in the canal was 96.7% and 63.3%, 76.7%, 73.1%, 67.6%, 70%, for CBCT, respectively. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of digital periapical radiography in detection of a fracture file #35 in the canal was 93.3%, 96.7%, 96.6%, 93.5% and 95%, and 36.7%, 76.7%, 61.1%, 54.8%, 56.66%, for CBCT, respectively. Conclusion: Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of digital periapical radiography was better than the CBCT technique in both sizes of broken files.

Maintenance of cell viability in extraoral conditions for a case of intentional replantation to retrieve a separated endodontic instrument.

Intentional replantation has been used as an alternative treatment modality to tooth extraction and prosthetic replacement when conventional endodontic treatment modalities are unfeasible or contraindicated. This case report presents a successful case of intentional replantation for the mandibular first molar with an endodontic mishap. An endodontic instrument was separated in the apical third of the root canal and extended beyond its mesiobuccal root apex. Intentional replantation served as a means to remove the separated instrument. The periodontal ligament (PDL) cells were kept viable throughout the endodontic treatment using a distinctive technique, wherein a preoperative impression is used for continuous wetting with saline. Platelet-rich fibrin (PRF) was shredded and placed in the alveolar socket to enhance PDL cell reattachment and prevent ankylosis. The 2-year successful follow-up reinforced that intentional replantation can be a viable option for removal of separated instruments that lie beyond the root apex. The use of these techniques to keep PDL cells viable and the use of PRF can aid in prevention of ankylosis.

Stress distribution in a mandibular premolar after separated nickel-titanium instrument removal and root canal preparation: a three-dimensional finite element analysis.

OBJECTIVE: This study used finite element analysis (FEA) to assess the von Mises stresses of a mandibular first premolar after removing a separated instrument with an ultrasonic technique. METHODS: FEA models of the original and treated mandibular first premolar were reconstructed, and three models (the original canal, size 30/taper 0.04 canal, and separated instrument removal canal) were created. Two-direction (vertical and lateral) loading patterns were simulated with a 175-N force. The maximum von Mises stresses of the models within the roots from the apex to the cervical region were collected and summarized. RESULTS: Under vertical and lateral loads, all maximal values in the three models were localized in the straight-line access region. Compared with the original model (model 1), the treated models (models 2 and 3) had greater maximum stress values from the apex to the cervical region. Greater differences in the maximum von Mises stresses between models 2 and 3 were present in the straight-line access region. CONCLUSIONS: Separated instrument removal caused changes in stress distribution and increases in stress concentration in the straight-line access region of roots.

Management of fractured root canal treated mandibular molar with separated endodontic instrument extending in periapical region.

The aim of this article is to present a case which demonstrates that debriding and disinfecting the infected, under-obturated canal of a tooth using standardized orthograde technique along with surgical retrieval of separated periapical instrument, heals the lesion of endodontic origin. Restoring the tooth with a definitive restoration involving core and crown reinstates the fractured tooth as a functional member of dental arch.

Broken instrument retrieval with indirect ultrasonics in a primary molar.

BACKGROUND: The separation of a file during pulpectomy is a rare incident in primary teeth due to inherently wider and relatively straighter root canals. A broken instrument hinders the clinician from optimal preparation and obturation of the root canal system invariably leading to failure, although in such teeth, an extraction followed by suitable space maintenance is considered as the treatment of choice. This case report demonstrates successful nonsurgical retrieval of a separated H file fragment in 84. CASE REPORT: A 7-year-old girl was referred to the Department of Paedodontics and Preventive Dentistry for endodontic management of a primary tooth 84 with a dento-alveolar abscess. Her medical history was noncontributory. After diagnosing a broken H file in the mesio-lingual canal, the tooth was endodontically treated in two appointments. At the first session, a broken file was successfully retrieved after using low intensity ultrasonic vibrations through a DG 16 endodontic explorer viewed under an operating microscope. After abscess resolution, Vitapex root canal obturation with a preformed metal crown cementation was completed at a second session. FOLLOW-UP: The patient was recalled at 3, 6, 12 and 15 month interval and reported to be clinically asymptomatic and radiographically with complete furcal healing. CONCLUSION: Integration of microscopes and ultrasonics in paediatric dental practice has made it possible to save such teeth with a successful outcome. Favourable location of the separated file, relatively straighter root canal system and patient cooperation resulted in successful nonsurgical management in this case.

Radiographic identification of separated instruments retained in the apical third of root canal-filled teeth.

INTRODUCTION: The aim of the study was to compare the diagnostic ability to radiographically detect separated stainless steel (SS) versus nickel-titanium (NiTi) instruments located at the apical third of filled root canals with either AH 26 (Dentsply DeTrey GmbH, Konstanz, Germany) or Roth sealer (Roth International Ltd, Chicago, IL). METHODS: Sixty single-rooted extracted human teeth with 1 straight root canal were instrumented to a size 25 apical diameter. In 40 teeth, apical 2-mm segments of SS (n = 20) or NiTi (n = 20) files were intentionally fractured in the apical part of the root canal. The remaining 20 teeth without fractured files served as a control group. Subsequently, the root canals were filled using laterally condensed gutta-percha and either AH 26 sealer (AH) or Roth sealer (Roth). All teeth were radiographed using conventional Kodak film (Eastman Kodak Co, Rochester, NY) and a charge-coupled device digital sensor. The evaluation of the images for the presence of a fractured instrument was performed independently by 2 blinded observers. The data were statistically analyzed using McNemar and Fisher exact tests. RESULTS: The kappa values were 0.76 and 0.615 for the first and second observers, respectively, and 0.584 between the observers. There were no significant differences in the diagnostic ability between digital and conventional radiography or the different root canal sealers (AH vs Roth, P > .05). The sensitivity to detect fractured SS was significantly higher than NiTi (P < .05). CONCLUSIONS: It may be difficult to radiographically detect a retained separated instrument. It is easier to radiographically detect fractured SS than NiTi instruments retained at the apical third of the root canal.

Retrieval of a separated nickel-titanium instrument using a modified 18-guage needle and cyanoacrylate glue: a case report.

During root canal preparation procedures, the potential for instrument breakage is always present. When instrument breakage occurs, it leads to anxiety of the clinician and as well as a metallic obstruction of the canal which hinders further cleaning and shaping. Separated instruments must always be attempted for retrieval and if retrieval is not possible bypass should be tried. With the increased use of nickel-titanium (NiTi) instruments the incidence of separated instruments has increased. A considerable amount of research has been done to understand the various factors related to the fracture of NiTi instruments to minimize its occurrence. This paper presents a review of the literature regarding the fracture of NiTi instruments and also describes a case report showing the use of a modified 18-guage needle and cyanoacrylate glue to retrieve a separated NiTi instrument from the mesiolingual canal of a mandibular first molar.