Instrument Fracture Research Articles

Accidental nasal fossa perforation during endodontic treatment - Case report

Fracture of an endodontic instrument within the root canal system can occur due to incorrect use of instruments, and clinicians are confronted with a few removal options when considering this situation. The purpose of this article is to present the removal of a fractured endodontic file from the periapical region of the right upper central incisor, that caused a nasal floor perforation and otorhinolaryngological symptoms, with the aid of a dental operating microscope (DOM) and cone bean computed tomography (CBCT). Success was achieved when the fragment was visible and removed from the nasal fossa. The standardized techniques of removal or bypassing fracture file were not effective, and success was obtained with the aid of CBCT that made possible the visualization of the broken file inside the nasal fossa.

Computer-aided design-CAM-guided endodontic microsurgical localization and retrieval of two separated instruments from the periapical area of a mandibular second molar

Three-dimensional (3D) imaging devices used for the visualization of anatomic structures not only allow for a more accurate diagnosis but also facilitate precise planning of surgical treatments, such as in guided surgery for instrument retrieval using templates. The innovative template-based treatment methods could also play a crucial role in future modern surgical endodontic treatments, enabling exact preplanning and precision-guided surgical interventions, and resulting in greater accuracy and success rates. We present here a case of a patient with a periapical lesion below a right mandibular second molar, with a fractured file segment extruding beyond the apex in the distal canal, and another instrument half-way extruded from the mesial canal, with radiolucencies evident at the mesial and distal root apices. The patient was treated by employing a 3D-guided microsurgical approach. First, 3D optical scans were imported into a guided surgery program. Periapical lesions and extruded fractured instruments were marked within the software. The osteotomy size, apical resection level, and bevel angle were defined pretreatment. This case introduces a novel-guided microsurgical endodontic technique, incorporating recommended guidelines of modern surgical endodontic treatment with the aid of 3D-printed surgical templates, by which minimally invasive surgical treatment was ensured with preservation of tooth, bone, and surrounding anatomical structures.

The ability of reciprocating glide path instruments to reach the full root canal working length.

This study evaluated the ability of reciprocating glide path instruments to reach the full working length (RFWL). Thirty mesial roots of mandibular molars were matched into 2 groups (n = 15 teeth, 30 root canals), according to the system used for glide path: WaveOne Gold Glider (WOGG) and R-Pilot. The samples with fractured instruments or when it was not possible to RFWL were scanned using micro-computed tomography. Fractured instruments were also visualised through a scanning electron microscopy to verify the type of fracture. The parameters were compared statistically by Fisher's and chi-square tests (P < 0.05). No instrument fractures were observed in the R-pilot, while 2 fractures occurred in the WOGG group (P > 0.05). RFLW was achieved in 29 canals (96.66%) and 28 canals (93.33%) with R-pilot and WOGG instruments, respectively (P > 0.05). The instruments are able to RFWL in mesial canals of mandibular molars. WOGG showed two fractures while no R-Pilot instruments fractured.

Removal of fractured endodontic NiTi file in the apical third of the root canal using an alternative approach. A case report

This case report presents an alternative approach for the removal of a fractured endodontic instrument from the apical third of the root canal. A 52-years-old female patient was referred for specialized endodontic treatment of the maxillary left first molar due to the presence of a periapical lesion and root canal calcification. After clinical and radiographic examination, the calcification was confirmed. During biomechanical preparation, the fracture of a size 25/.06 NiTi reciprocating file (ProDesign R) occurred in the apical third of the palatine canal. The patient was informed about the complication and agreed with the attempt to remove the fragment. Firstly, a slight wear of the dentinal walls around the fragment was made using ultrasonic inserts under magnification. Then, a customized extractor was made using a hypodermic needle and a handling file whose mechanism is similar to the removal method previously described by Masserann. For this, the hypodermic needle was inserted in the root canal and the handling file was adapted in the needle lumen, with the function of fixing the fragment and removing it from the canal through the opposite movement performed by the fractured file. After associating the technique with a hypodermic needle and using ultrasound and an operating microscope to perform the procedure, the fragment was successfully removed. The association of techniques to remove fragments using only items already present in the endodontic arsenal can eliminate the need for surgical treatment and improve the prognosis of endodontic treatment through a safe, simple and cost-effective method that can be performed in the endodontic clinical routine.

INTENTIONAL REPLANTATION- A VIABLE SOLUTION FOR INSTRUMENT SEPARATION: A CASE REPORT

The fracture of an endodontic instrument is an obstacle in the completion of successful endodontic therapy. Non-surgical re-treatment and surgical endodontics are not always viable solutions. The various methods of re-treatment for a separated instrument include le bypass, le retrieval or the surgical method of Apicoectomy. However, the mode of treatment also depends on the position of the separated instrument in the tooth, the anatomy of the tooth and also the root. In certain cases, le bypass or retrieval is not advocated. In such cases, other options for re-treatment are needed to be considered. Intentional replantation is a treatment option considered by many as a procedure of last resort when non-surgical and surgical endodontics is contraindicated. This procedure is often indicated where the separated instrument is at or beyond the apex. The case report discussed in this paper presentation demonstrates the procedure of intentional replantation as a viable solution where other retreatment procedures are not possible.

Shaping Ability and Debris Extrusion of New Rotary Nickel-Titanium Root Canal Instruments.

The aim was to evaluate the canal straightening and the amount of apically extruded debris associated with five rotary nickel-titanium when preparing curved root canals. A total of 100 root canals in extracted human teeth (angles of curvatures 20°–30°; radii 5.9–13.5 mm) were divided into five groups (n = 20/group). The groups were balanced with respect to the angle and the radius of canal curvature. The root canals were prepared using conventional austenite 55-NiTi alloy instruments F360, F6 SkyTaper (both Komet, Lemgo, Germany), and the heat-treated NiTi Jizai, Silk-Complex and Silk-Standard instruments (all Mani, Tochigi, Japan) to an apical size 25. The amount of extruded debris was assessed with a micro balance. Statistical analysis was performed using Kruskal–Wallis test with Bonferroni correction at a significance level of p < 0.05. During canal preparation, neither instrument fractures nor procedural preparation errors were noticed. Regarding canal straightening, the use of Jizai instruments resulted in the significantly lowest straightening (p < 0.05), while no significant differences were obtained between all other groups (p > 0.05). Regarding the amount of apically extruded debris, no significant differences between all groups were obtained (p > 0.05). Within the limitations of this study, all instruments performed well, and especially the Jizai instruments showed an excellent shaping ability.

Does the Endodontic Education Level Affect Decision-Making for Endodontically Treated Teeth With Apical Periodontitis? A Web-Based Survey

ObjectivesThe management of endodontically treated teeth with apical periodontitis is debated among clinicians. The aim of this study was to evaluate treatment choices for endodontically treated teeth with different sizes of periapical lesions among endodontists, endodontics postgraduate students, general dental practitioners, and undergraduate students who had fulfilled their theoretical and clinical training in endodontics. Materials and MethodsPeriapical lesion images (no periapical lesion and 1-mm, 3-mm, and 5-mm periapical lesions) were formed on 4 different radiographs with a software program, and the survey included 16 radiographs that were emailed to 1881 participants. Treatment options included extraction, surgical or nonsurgical retreatment, and wait and see. The χ2 test was used to compare the responses of the participants. ResultsThe survey was returned by 1039 participants (55.23%). There were statistically significant differences among the responses of all participants for all cases (P < .05), except a case with a broken file and no lesion (P = .918). All participants decided to extract at an increased size from a 1-mm periapical lesion to a 5-mm periapical lesion. At all lesion sizes, general dental practitioners planned retreatment less when compared with other groups. ConclusionsThis survey study showed that there was a positive correlation between endodontic education level and retreatment decision-making. Dentists who confront seemingly hopeless endodontically treated teeth such as an instrument fracture, a missing canal, or a large periapical lesion should consult with an endodontist before making the decision to extract the tooth.

Clinical fracture incidence of rotary and reciprocating NiTi files: A systematic review and meta-regression.

This systematic review was registered in PROSPERO (CRD42017075917) and aimed to investigate whether the available clinical evidence supports the hypothesis that reciprocating motion results in a lower incidence of nickel-titanium files fracture compared to continuous rotation. Clinical studies that reported the incidence of fracture of engine-driven nickel-titanium files were included. The main exposure was the kinematics, and the primary outcome was the incidence of files fracture. The overall incidence of files fracture was 2.27%, with a trend for higher incidence with rotary motion (2.43%) than with reciprocating (1.0%), though without significant differences. Multiple meta-regression models revealed that the use of nickel-titanium files in more than four teeth and less proficient operators were associated with a higher incidence of file fracture. There was no difference in the clinical incidence of fracture of nickel-titanium instruments between reciprocating and rotary motions; however, other factors were identified.

Effect of number of uses and sterilization on the instrumented area and resistance of reciprocating instruments

ObjectivesThis study evaluated the effect of repeated uses and autoclaving in the instrumented area, fracture resistance, and time of instrumentation of thermally treated nickel-titanium reciprocating systems.Materials and MethodsTwo hundred simulated canals were instrumented using Reciproc Blue and WaveOne Gold. Each file was used up to 10 times or until fracture. The instrumented area was measured in pre- and post-operative images, using ImageJ software. Kaplan-Meier survival analysis evaluated the number of uses of instruments before fracture. Instrumented area and time of instrumentation were analyzed by Mann-Whitney U test and Kruskal-Wallis. Correlations among the number of uses and instrumented area were measured. The level of statistical significance was set at p < 0.05.ResultsReciproc Blue presented a higher estimated number of uses in comparison with WaveOne Gold (p = 0.026), but autoclaving did not affect the resistance to fracture of instruments (p > 0.05). The instrumented area was different among the evaluated groups (p = 0.039), and the instrumented area along the uses of both tested instruments was reduced. With the time of instrumentation, there was also a significant difference among the evaluated groups; the groups without sterilization cycles were faster, in comparison to those submitted to autoclaving (p = 0.010).ConclusionsReciproc Blue was more resistant than WaveOne Gold, suffering later fracture. Additionally, the sterilization cycles did not influence the estimated number of uses of thermally treated reciprocating instruments, but the instrumented area of root canals was reduced along with the repeated uses of both instruments.

Effect of flushing temperature on preparation ability of rotary nickel-titanium files.

The effect of flushing at different temperatures on the preparation ability of rotary nickel-titanium files was investigated to provide guideline for clinical application. Sixty ProTaper Universal F1 rotary nickel-titanium files were randomly divided into three groups treated by flushing at 6°C, 23°C, and 40°C. Root canal preparation was conducted by step-by-step method on standardized nickel-titanium instrument fracture models. During preparation, the thrust force was set as 10 N, and water was continuously flushed. The motor speed was 350 rpm (rounds per minute), and the torque was 3.0 N cm. When the set torque was reached, the motor automatically rotated in the reverse direction and was pulled out. Root canal preparation was performed using ProTaper Universal F1 rotary nickel-titanium files treated by flushing. The numbers of rotations before the device was fracture were 429.33 ± 214.68, 821.92 ± 410.43, and 1304.92 ± 297.81, respectively. When each root canal was completed, the numbers of instrument rotations were 272.15 ± 88.30, 188.85 ± 34.36, and 163.41 ± 16.18, respectively. Rank sum test and analysis of variance were performed by IBM SPSS Statistics v21.0 software, and both of them were p < 0.01, indicating that the number of cycles to failure (NCF) and the number of instrument rotations for each root tube were statistically different at the three temperatures. The self-made resin-simulated curved root canal can replace the real root canal to complete the root canal preparation experiment. The group of nickel-titanium files treated by flushing at 23°C can prepare more root canals and prolong the life of nickel-titanium files than at 6°C. When flushing was done at 40°C, the number of root canals prepared by nickel-titanium files was the highest, and it was not easy to damage the instrument, but lateral perforation occurred easily during root canal preparation.

Fracture incidence of Reciproc instruments during root canal retreatment performed by postgraduate students: a cross-sectional retrospective clinical study.

ObjectivesTo evaluate the fracture incidence of Reciproc R25 instruments (VDW) used during non-surgical root canal retreatments performed by students in a postgraduate endodontic program.Materials and MethodsFrom the analysis of clinical record cards and periapical radiographs of root canal retreatments performed by postgraduate students using the Reciproc R25, a total of 1,016 teeth (2,544 root canals) were selected. The instruments were discarded after a single use. The general incidence of instrument fractures and its frequency was analyzed considering the group of teeth and the root thirds where the fractures occurred. Statistical analysis was performed using the χ2 test (p < 0.01).ResultsSeven instruments were separated during the procedures. The percentage of fracture in relation to the number of instrumented canals was 0.27% and 0.68% in relation to the number of instrumented teeth. Four fractures occurred in maxillary molars, 1 in a mandibular molar, 1 in a mandibular premolar and 1 in a maxillary incisor. A greater number of fractures was observed in molars when compared with the number of fractures observed in the other dental groups (p < 0.01). Considering all of the instrument fractures, 71.43% were located in the apical third and 28.57% in the middle third (p < 0.01). One instrument fragment was removed, one bypassed, while in 5 cases, the instrument fragment remained inside the root canal.ConclusionsThe use of Reciproc R25 instruments in root canal retreatments carried out by postgraduate students was associated with a low incidence of fractures.

EFFECT OF SODIUM HYPOCHLORITE IMMERSION AND AUTOCLAVE STERILIZATION ON FRACTURE RESISTANCE OF PROTAPER GOLD NITI ROTARY INSTRUMENTS

Background: Instrument fracture is a common problem faced during root canal preparation. The present study aimed to analyse the effect of sodium hypochlorite (NaOCl) immersion and autoclave sterilization on fracture resistance of ProTaper Gold NiTi rotary instruments in artificial canals. Methods: An observational study was performed using forty new ProTaper Gold rotary NiTi instru­ments. The files were divided into four groups (N=10) with Control (no immersion/ sterilization), one cycle each of NaOCl immersion and sterilization, five cycles each of NaOCl immersion and sterilization, and ten cycles each of NaOCl immersion and sterilization. The instruments were im­mersed in NaOCl for five minutes in all test groups, and were subjected to cyclic fatigue testing in artificial canals with 25 mm length, 60° curvature, and radius of curvature 4 mm. The number of cycles to fracture (NCF) was calculated for each instrument. The obtained data were subjected to statistical analysis (p-value &lt; 0.05). The Kolmogorov Smirnov test was performed to examine the normality distribution of the NCF values. One-way ANOVA test was used to compare the mean NCF values for the different groups. Results: Sodium hypochlorite immersion and autoclave sterilization exhibited no significant dif­ference in NCF values between the control and test groups (p-value &gt; 0.05). All the experimental groups demonstrated comparable NCF values and significant difference was not found between the groups (p-value &gt; 0.05). Conclusions: Repeated cycles of sodium hypochlorite immersion and autoclave sterilization do not seem to influence ProTaper Gold instruments’ fracture resistance.

Association of the location of instrument fracture and its retrieval

Association of the location of instrument fracture and its retrieval

Fracture of endodontic instruments - Part 1: Literature review on factors that influence instrument breakage

Instrument fracture is a serious complication during endodontic treatment of teeth, having an adverse effect on the outcome of the nickel titanium (NiTi) treatment, especially if the fracture prevents apical access to the infected root canal. Despite the advent of NiTi files, the risk of fracture during the endodontic preparation of root canals, especially in severely curved canals, remains a serious concern. The fracture of NiTi files during preparation may result in a compromised prognosis for the tooth. In the presence of periapical lesions, instrument fracture may reduce the chances of successful healing.

Modern considerations when approaching fractured endodontic instruments - Part 2: A review of the literature and clinical techniques

Once root canal treatment is considered, the treating clinicians must be aware of the real possibility that complications and unforeseen accidents can occur during any stage of the treatment. Complications and accidents may include instrument separation, root perforation on different levels and ledge formation.

P78. Spinopelvic sagittal imbalance as a risk factor for fracture type of proximal junctional failure after posterior instrumented fusion

BACKGROUND CONTEXT Postoperative fracture of the upper instrumented vertebrae (UIV) is thought to be a fracture type of proximal junctional failure (PJF), which usually needs for proximal extension of the fusion. Global sagittal imbalance has been considered as a potential risk factor to develop PJF. Spinopelvic parameters, such as the pelvic incidence (PI) angles, sacral slope (SS) angles, and pelvic tilt (PT) angles have been recognized to affect overall sagittal balance. PURPOSE To investigate the influence of spinopevic parameters including pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), and proximal local kyphosis (PLK) angle on the development of fracture type of PJF after posterior instrumentation for degenerative lumbar diseases. STUDY DESIGN/SETTING A retrospective case-control cohort study. PATIENT SAMPLE Ninety-six patients. OUTCOME MEASURES Clinical outcomes were evaluated with Oswestry Disability Index (ODI) and the visual analogue scale (VAS) for leg and back pain. The medical conditions were reviewed using the weighted Charlson Comorbidity Index (CCI), bone mineral density (BMD) with T score, and body mass index (BMI). Radiographic parameters such as coronal Cobb's angle, PI, SS, PT, LL, and PLK were measured for comparison. The prevalence of osteoporotic compression fractures (OVFx), PI-LL, and score for spinopelvic realignment achievement were calculated. METHODS Between January 2007 and December 2017, patients underwent posterior instrumented fusion were reviewed. This was a retrospective 1:3 matched case-control study. Twenty-four patients who had undergone revision surgery for UIV fracture of PJF after posterior instrumented fusion were categorized as the study group. As a control group, 72 age-, sex-, and surgical level- matched patients who had undergone posterior instrumented fusion during the same period, had no development of UIV fracture of PJF for more than two years. RESULTS Before surgery, the study group already had more comorbidities (CCI: 1.75 ± 0.90 vs 1.22± 0.61, p= 0.002), poorer bone density (T score: -3.41 ± 1.12 vs -1.81± 0.83, p= 0.001), significant higher prevalence of OVFx (46% vs 18%, p = 0.006) than the control group. In terms of preoperative radiographic parameters, the study group had significantly lower LL (22.85o ± 17.15o vs 31.66o ± 15.10o, p= 0.030), SS (22.69o ± 10.69o vs 28.34o ± 12.66o, p= 0.043), and significantly higher PLK (2.98o ± 9.23ovs -9.20o ± 12.89o, p CONCLUSIONS In addition to osteoporoitc bone quality, pre- and postoperative lower LL, and higher PI-LL/PLK were also significantly associated with development of UIV fracture in PJF. Therefore, obtaining appropriate LL and correcting PLK should be done at surgery to improve spinopelvic sagittal imbalance. The results suggest that the achievement of appropriate LL and PI-LL prevents instrumented fracture of PJF after posterior instrumented fusion. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Fracture incidence of WaveOne Gold files: a prospective clinical study.

This prospective clinical study evaluated the incidence of instrument fracture observed after single-file root canal treatment of molars using WaveOne Gold instruments. Three standardized, experienced and calibrated specialists treated 750 maxillary and mandibular molars with curvatures less than 45° (2691 root canals) over a 12-month period. All the treatments were performed in a single session. A total of 1104 WaveOne Gold instruments were used, including 38 small, 750 primary, 228 medium and 88 large instruments. Intracanal procedures were performed according to the manufacturer's recommendations, and each instrument was used in a single clinical case. The instruments were examined after their removal from the canal, under an operating microscope at 8× magnification. No fractures were observed in any of the 1104 instruments used. No fractures of WaveOne Gold reciprocating instruments occurred during root canal preparations performed in maxillary and mandibular molars with curvatures less than 45° when used strictly according to the manufacturer's recommendations and applied in a single clinical case.

Retrieval of fractured Endodontic Instrument under dental operating microscope using ultrasonic tips : A Case Report

A Patient came with the complaint of pain in the lower right back region of the jaw. Root canal treatment was planned. While preparing for the bio-mechanical procedure, the Hand pro taper fractured in the apical third. Iatrogenic occurred as a result of the fracture of the endodontic instrument. Retrieval of the fractured instrument was planned to complete the cleaning and shaping of the canal. The removal of the fractured instrument was planned to be done under the Dental Operating Microscope. The use of an operating microscope enhanced the illumination and the magnification of the instrument. This illumination and magnification helped in the precision of removal. The ultrasonic tip enabled to reach of the fractured instrument in the canal and loosen the dentin around the fractured instrument. It allowed easy retrieval of the fractured instrument. During the retrieval procedure, the fractured instrument was bypassed before the use of the ultrasonic tip. After the removal of the fractured instrument, cleaning and shaping were completed, followed by obturation, definitive restoration, and prosthesis. As the removal of the fractured instrument enabled complete cleaning and shaping, it improved the prognosis of the case. When the endodontic instrument gets fractured, it should be analyzed over the radiograph to assess the fracture level, the anatomy of the root canal, size of the fractured instrument, check accessibility, stage of fracture, etc. If all the above criteria are met with the removal of the instrument only then, replacement should be tried. Otherwise, it may lead to a severe loss of root dentin, decreasing fracture resistance of the root.

The Strange Case of a Broken Periodontal Instrument Tip

This case report describes a rare case of a broken periodontal probe tip and its removal. A male patient presented himself in June 2019 due to a painful tooth in the upper left quadrant. The patient elected treatment in the dental school’s student course. In October 2019, in preparation for full-mouth rehabilitation, a complete diagnostic status was performed, including radiographs. In this context, a metal-dense fragment was identified in the apical region of the (missing) tooth 45. It was diagnosed as the broken tip of a periodontal probe (type AE P OWB). Since a PCP-12 probe is generally used in-house, iatrogenic damage during the initial examination or student course could be excluded a priori. The patient was not able to remember any treatment that could be associated with the instrument’s breaking. Since the probe fragment was palpable and a translocation could not be precluded, the patient agreed to its removal under local anesthesia, after a cone-beam CT. This article describes and discusses this particular case, with special emphasis on iatrogenic instrument fractures and their removal.

CLINICAL APPROACH TO THE MANAGEMENT OF FRACTURED INSTRUMENTS USING ULTRASONICS AND THE INSTRUMENT RETRIEVAL SYSTEM UNDER THE DENTAL OPERATING MICROSCOPE

Background: Instrument separation has become a major concern in the endodontic practice today. In cases where the fractured fragment completely blocks the canal, the access of disinfecting irrigants to the root canal system is limited. Literature suggesting the guidelines on the management of broken instruments is scanty. This study was aimed to establish a preliminary guideline in the management of cases with instrument fracture using the Ultrasonic tips, the Instrument Retrieval System (IRS) and Instrument bypass under the Dental Operating Microscope (DOM).&#x0D; Methods: 40 cases were selected with fractured instruments and categorized as follows-location coronal or apical to curvature- size of greater than or less than 5 mm. Patients were informed about the procedure and its complications, following which consent was taken. Management was planned in three stages. Instrument retrieval with the aid of Ultrasonics was performed under the DOM in stage 1. Retrieval using IRS was performed in stage 2. Instrument bypass was performed in stage 3. Success rate was compared using statistical analysis by the StatPac software.&#x0D; Results and conclusion: Fractured fragments with a length of less than 5mm and straight line access was retrieved successfully under the DOM using the Ultrasonics in 87.5% cases. Retrieval of fragments greater than 5mm and with a straight line access was successful with the added use of the Instrument Retrieval system/ Instrument extractor in 71.4% cases.&#x0D; Keywords: Ultrasonic, Instrument Retrieval System, Dental Operating Microscope, instrument bypass, fractured instrument&#x0D; Key Message: Instrument fracture in an endodontic practice is a stressful event. With the widespread use of rotary instruments, the incidence of instrument separation has increased. With increasing referral of such cases, management of these cases with a predictable outcome has become important in endodontic specialty. An attempt has been made to lay down guidelines regarding management of cases with fractured instruments.