Clinical and radiographic features of external cervical resorption - An observational study

AIM

To determine the prevalence of symptoms, clinical signs and radiographic presentation of external cervical resorption (ECR).

METHODOLOGY

This study involved 215 ECR lesions in 194 patients referred to the Endodontic postgraduate Unit at King's College London or Specialist Endodontic practice (London, UK). The clinical and radiographic findings (periapical [PA] and cone beam computed tomography [CBCT]) were readily accessible for evaluation. A checklist was used for data collection. Inferential analysis was carried out to determine if there was any potential association between type and location of tooth in the jaw as well as sex, age of the patient and ECR presentation and radiographic feature.

RESULTS

Eighty-eight patients (94 teeth) were female and 106 patients were male (121 teeth), the mean age (±SD) was 41.5 (±17.7) years. Fifteen patients (7.7%) had more than one ECR lesion. The most affected teeth were maxillary central incisors (21.4% [46 teeth]) and mandibular first molars (10.2% [22 teeth]). ECR was most commonly detected as an incidental radiographic finding in 58.1% [125 teeth] of the cases. ECR presented with symptoms of pulpal/periapical disease in 23.3% [n = 50] and clinical signs (e.g. pink spot, cavitation) in 16.7% [36 teeth] of the cases. Clinical signs such as cavitation (14%), pink spot (5.1%) and discolouration (2.8%) were uncommon, but their incidence increased up to 24.7% when combined with other clinical findings. ECR was detected in the resorptive and reparative phases in 70.2% and 29.8% of the cases respectively.

CONCLUSION

ECR appears to be quiescent in nature, the majority being asymptomatic and diagnosed incidentally from PA or CBCT. When assessed with the Patel classification, most lesions were minimal to moderate in relation to their height (1 or 2) and circumferential spread (A or B). However, the majority of ECRs were in (close) proximity to the pulp. Symptoms and clinical signs were associated with (probable) pulp involvement rather than the height and circumferential spread of the lesion. Clinical signs were more frequently associated when ECR affected multiple surfaces.

Accuracy of CAD-CAM surgically guided tooth autotransplantation using guided templates and custom-designed osteotomes in human cadaver mandibles

INTRODUCTION

A major challenge in dentistry is the replacement of teeth lost prematurely due to trauma, caries, or malformations, especially in growing patients. The aim of this study was to assess the accuracy of CAD-CAM surgically guided tooth autotransplantation in cryopreserved cadaver mandibles using guided templates and custom-designed osteotomes.

METHODS

Cryopreserved human cadaver heads were digitized and scanned using an intraoral optical scanner and a large-volume cone beam computed tomography (CBCT) device. First, virtual surgical planning was performed to create a 3D tooth replica, two surgical guides, and a custom-made osteotome for each single-rooted tooth autotransplantation procedure/case. Surgical sockets were created in the selected mandibles using guided tooling consisting of an initial guided osteotomy with implant burs and a final guided osteotomy using custom osteotomes. After tooth autotransplantation, second large-volume CBCT images of the five cadaver mandibles were obtained. The discrepancy in mm within the 3D space (apical and mesiodistal deviations) between the final position of the autotransplanted teeth and their digitally planned 3D initial position was calculated and analyzed statistically (P< .05).

RESULTS

All donor teeth were placed without incident within their newly created sockets in the real mandibles. The mean difference between the digitally planned root apex position and the final tooth position was 2.46±1.25mm. The mesiodistal deviation of the autotransplanted teeth was 1.63±0.96mm.

CONCLUSIONS

The autotransplantation of single-rooted teeth with custom-designed and 3D-printed surgical tooling provided promising results. The technique was able to create surgically prepared sockets that could accommodate transplanted teeth in mandibles.

A Free App for Diagnosing Burnout (BurnOut App): Development Study

Background

Health specialists take care of us, but who takes care of them? These professionals are the most vulnerable to the increasingly common syndrome known as burnout. Burnout is a syndrome conceptualized as a result of chronic workplace stress that has not been successfully managed.

Objective

This study aims to develop a useful app providing burnout self-diagnosis and tracking of burnout through a simple, intuitive, and user-friendly interface.

Methods

We present the BurnOut app, an Android app developed using the Xamarin and MVVMCross platforms, which allows users to detect critical cases of psychological discomfort by implementing the Goldberg and Copenhagen Burnout Inventory tests.

Results

The BurnOut app is robust, user-friendly, and efficient. The good performance of the app was demonstrated by comparing its features with those of similar apps in the literature.

Conclusions

The BurnOut app is very useful for health specialists or users, in general, to detect burnout early and track its evolution.

Influence of Cone-beam Computed Tomography in clinical decision-making among different specialists in External Cervical Resorption lesions: a before-after study

INTRODUCTION

Inadequate management of external cervical resorption (ECR) lesions may impact the treatment outcome. This study aimed to ascertain the influence of cone-beam computed tomography (CBCT) in clinical decision-making choices in cases of ECR among dentistry specialists (endodontics, prosthodontics, oral surgery, periodontics orthodontics, and general dentistry). A secondary objective was to evaluate the self-reported level of difficulty in choosing a treatment plan before and after viewing the CBCT images.

METHODS

Sixty examiners from different specialties were chosen to evaluate 12 cases of ECR lesions. Each case included clinical photographs, digital periapical (PA) radiographs, and a small-volume CBCT scan. In the first assessment, the examiners were given all the relevant information of each case, except the CBCT scan. Each examiner was asked to select 1 of the proposed treatment options and assess the difficulty of decision making. Four weeks later, the examiners randomly reviewed the same 12 cases with additional information from the CBCT data.

RESULTS

After the CBCT evaluation, the clinicians changed their treatment plan in 72.2% of the cases (P < .05). The self-reported level of difficulty in choosing a treatment changed in all groups after evaluating the CBCT scans (P< .05). After viewing the CBCT scan, the extraction option increased significantly in all groups (P < .05).

CONCLUSIONS

CBCT scan had a significant impact on clinical decision-making in cases of ECR evaluated by different specialists.

Direct oral anti-coagulants in patients with atrial fibrillation and bioprosthetic valve: a meta-analysis of randomized controlled trials

Background

Patients with atrial fibrillation (AF) and bioprosthetic valve (BPV) are at increased risk for thromboembolic events and require anticoagulation. However, management strategies for these patients have not yet been well addressed by randomized controlled trials (RCTs). For years, warfarin was the only available oral anticoagulant, but this changed with the introduction of the direct oral anticoagulants (DOACs). However, there is no clear consensus about indications for DOACs in these patients due to the lack of prospective trials.

Purpose

The objective of this meta-analysis is to show the efficacy of DOACs in AF patients with BPV in terms of composite cardiovascular outcomes. In addition, the study aims to show the safety of DOACs in terms of major bleeding.

Methods

A comprehensive literature search for randomized controlled trials (RCTs) was performed in MEDLINE, PubMed and Clinicaltrials.gov in human subjects done within 2010 to 2020. Results were pooled using fixed effects. The primary outcome was a composite cardiovascular outcome from all included studies, which include death, major bleeding and major adverse cardiac events (stroke, transient ischemic attack, valve thrombosis, myocardial infarction, systemic embolism, and hospitalization for heart failure). Secondary outcomes include all-cause stroke or systemic embolism, major bleeding, death from cardiovascular cause and all-cause death.

Results

Four RCTs were included in the meta-analysis. DOACs used were Apixaban, Dabigatran, Edoxaban and Rivaroxaban. In patients with AF and BPV, DOACs performed similarly with warfarin in terms of composite cardiovascular outcome (RR 1.01, 95% CI 0.86–1.19, P=0.88, I2=0%). On the other hand, DOACs performed better than warfarin in reduction of all cause stroke and systemic embolism (RR 0.48, 95% CI 0.27–0.87, P=0.01). There is non-statistically significant risk reduction for major bleeding (RR 0.81, 95% CI 0.56–1.17, P=0.26, I2=0%) and other secondary outcomes such as death from cardiovascular causes (RR 0.79, 95% CI 0.39–1.60, P=0.51, I2=0%) and all cause death (RR 0.94, 95% CI 0.55–1.62, P=0.71, I2=0%) showing similar outcomes with NOACs and warfarin.

Conclusion

DOACs compared with warfarin are similar in terms of composite cardiovascular outcome, major bleeding and death. However, DOACs performed better than warfarin in reducing all-cause stroke/systemic embolism and can be an alternative for oral anticoagulation in patients with AF and BPV.

Funding Acknowledgement

Type of funding sources: None. Forest plot for all-cause stroke or systemic embolism

Magnetic extrusion for restoring teeth with a negative ferrule effect: a 2-year follow-up case report

The restoration of severely damaged teeth with no coronal structure requires an adequate supracrestal tissue attachment (STA) and a distance of at least 3 mm between the crown margin and the alveolar crest. Management of a tooth with no walls and only subgingival tooth structure implies that the tooth has no ferrule. Ferrule preparation from 1.5 to 2.0 mm with a circumference greater than 75% is crucial for a good medium- and long-term prognosis (especially at the anterior segments) and increases survival probability by 5%. Three main options may be considered to create space for a ferrule: crown lengthening, orthodontic extrusion or surgical extrusion. Although extrusion is widely performed with fixed orthodontic appliances using arch wires or elastics attached to the tooth, the same outcome can also be achieved with magnets. This article reports on a 56-year-old male with a severely damaged tooth 23 with no ferrule, which was an abutment of an In-Ceram alumina fixed partial denture (FPD). The treatment plan consisted of a magnetic extrusion of tooth 23 using a provisional tooth-implant FPD made of polymethyl methacrylate (PMMA). The treatment lasted approximately 10 months, with the last clinical and radiographic control carried out 2 years post-extrusion. The present case report aims to demonstrate that magnetic extrusion with an FPD provides a friction-free system in which the direction and amount of force can be manipulated. This technique offers an excellent alternative for the restoration of teeth with insufficient ferrule, or even with no ferrule. Further prospective studies and randomized controlled trials are needed to demonstrate the feasibility of this treatment option.

Magnetic extrusion technique for restoring severely compromised teeth: A case report

An orthodontic magnetic extrusion technique is described for the management of an extensively damaged maxillary premolar. A cylindrical neodymium-iron-boron (Nd₂Fe₁₄B) magnet was attached to the remaining tooth structure, and a second magnet was placed on a resin-bonded partial denture. A 4.5-mm extrusion was obtained after 3 adjustments, and the tooth was prepared with a 3-mm buccal and 2-mm lingual ferrule by following a biologically oriented preparation technique and restored with a monolithic zirconia crown. Eighteen months after completing the treatment, no evidence of soft tissue dehiscence, abnormal tooth mobility, endodontic failure, or root resorption was found.

Cone-beam Computed Tomographic Analysis to Detect the Association between Primary and Secondary Endodontic Infections and Mucosal Thickness of Maxillary Sinus

INTRODUCTION

This retrospective study used cone-beam computed tomographic (CBCT) imaging to evaluate the differences in the mucosal thickness of the Schneiderian membrane in primary and secondary endodontic lesions.

METHODS

A total of 121 CBCT scans were analyzed. Clinical features such as sex, age, size and volume of the periapical lesion, dimension of the bone, morphology, and relationship between the roots and the mucosal thickness were recorded and analyzed in primary and secondary endodontic lesions in CBCT sagittal and coronal planes. Data were analyzed using the chi-square test, the Mann-Whitney U test, and multiple logistic regression (P < .05).

RESULTS

Statistical analysis revealed no significant differences in membrane thickness between the primary and secondary lesions in the sagittal and coronal planes (P = .08 and .06). Differences between age groups were statistically significant in both groups (P < .05). The volume of the periapical lesions of the secondary endodontic lesions were statistically greater than that of the primary lesions (P < .05). Mucosal thickness prevalence increased when the volume of the lesion was greater, and the bone dimension was narrower in maxillary second premolars and first and second molars. Teeth with 2 or more affected roots were directly related to increased sinus mucosa thickening.

CONCLUSIONS

CBCT images showed no differences in mucosal thickening between primary and secondary endodontic lesions.

Autotransplantation of impacted maxillary canines into surgically modified sockets and orthodontic treatment: a 4-year follow-up case report

The permanent maxillary canine is the second most frequently impacted or displaced tooth. The standard treatment for an impacted canine includes, among other things, surgical exposure and orthodontic alignment. Surgical techniques for this procedure vary depending on whether the tooth is labially or palatally impacted, while orthodontic techniques vary according to clinical judgment and experience. Autotransplantation is a treatment alternative for impacted canines with complete root formation. The success of tooth transplantation depends on the vitality of the periodontal ligament (PDL) attached to the donor tooth, and its viability decreases when it is exposed extraorally. This article reports on maxillary canine autotransplantations combined with connective tissue grafts (CTGs) and orthodontics. The recipient mesiodistal space was created orthodontically and the recipient socket was prepared using dental implant drills. Following transplantation, bone defects were grafted using guided bone regeneration (GBR). At 4 years post-transplantation, the soft tissue level was stable and periapical radiographs showed a practically normal contour of the alveolar crest around teeth 13 and 23. The two permanent canines presented no root resorption and ankylosis, and no signs of inflammation or bleeding were observed. The procedure used in this case report demonstrates that canine transplantation combined with GBR, plastic surgery procedures, and orthodontic treatment may yield acceptable and predictable esthetic results.

European Society of Endodontology position statement: Use of cone beam computed tomography in Endodontics: European Society of Endodontology (ESE) developed by

This Position Statement represents a consensus of an expert committee convened by the European Society of Endodontology (ESE) on the use of Cone Beam Computed Tomography (CBCT) in Endodontics. This paper is an update of the ESE CBCT position statement which was published in 2014 (European Society of Endodontology 2014, https://doi.org/10.1111/iej.12267). Recent review articles provide more detailed background information and the basis for this position statement. It is intended that this position statement will be updated at least every 4-5 years to keep abreast of relevant research. The aim of this paper is to provide clinicians with evidence-based guidance on the application of CBCT in Endodontics. Since 2014, there has been an increase in the number of clinical studies confirming the positive impact of CBCT on treatment planning, decision-making when reviewing cases and reduced practitioner stress levels.

Cone beam computed tomography in Endodontics - a review of the literature

The use of cone beam computed tomography (CBCT) in the diagnosis and/or management of endodontic problems is increasing and is reflected in the exponential rise in publications on this topic in the last two decades. The aim of this paper is to: (i) Review current literature on the endodontic applications of CBCT; (ii) Based on current evidence make recommendations for the use of CBCT in Endodontics; (iii) Highlight the areas in which more research is required.

Invasive Cervical Resorption: Clinical Management in the Anterior Zone

According to the high number of articles published on invasive cervical resorption (ICR), this pathology, as commonly believed, is a more frequent form of cervical resorption. ICR is often misdiagnosed as internal resorption or caries, which leads to inappropriate treatment and even unnecessary tooth loss. Despite a correct diagnosis, the treatment of this type of hyperplastic invasive external resorption poses a challenge for the clinician. The Heithersay classification and the use of cone-beam computed tomographic imaging have increased our knowledge of the pathology and helped improve its prognosis. Nevertheless, there is no standard protocol for the treatment of this type of lesion. This article proposes a treatment protocol for ICR based on the pattern and location of resorption. Three treatment approaches (internal access, external access, and intentional replantation) are presented through 3 clinical cases.

Continuous Apical Negative-Pressure Ultrasonic Irrigation (CANUI): A new concept for activating irrigants

Background: Irrigation of the root canal system is an essential step in the endodontic treatment. The aim of this article is to introduce continuous apical negative-pressure ultrasonic irrigation (CANUI), a new irrigation concept, and compare the characteristics of this new technique with current devices for activating the irrigant. Material and Methods: CANUI is designed for cleaning and disinfecting the root canal system. The device consists of a tube inside another tube that allows the continuous ultrasonic exchange of fresh irrigant, as the irrigant is simultaneously aspirated apically. The coronal and apical tubes are 0.75 and 0.3 mm in diameter, respectively. It is composed of a nickel-titanium microcannula suitable for the working length of curved canals. Results: The CANUI technique has the advantages of apical negative pressure (to avoid apical extrusion of the irrigant) and continuous ultrasonic irrigation (continuous refreshment of the irrigant and forced introduction into the canal ramifications). Conclusions: The CANUI technique could improve the irrigation technique of dentists to reach more disinfection in endodontic treatments.

Key words:Apical negative pressure, continuous ultrasonic irrigation, irrigation in curved canals, irrigation systems.

Influence of academic training in endodontics and implantology on decision-making in undergraduate students

PURPOSE

To evaluate the effect of academic training on decision-making in a group of undergraduates who have undergone training in endodontics and implantology.

BASIC PROCEDURES

A single group of undergraduate dentistry students (n = 65) was given a survey consisting of 15 endodontic cases. Each case included periapical radiographs and clinical photographs. Students were asked to select one of the eight proposed treatments. In their 4th year, the students first responded to the survey after completing endodontics. One year later, after completing their studies in implantology, the same students completed the same survey again.

MAIN FINDINGS

Under the conditions of this study, differences in undergraduate training significantly affected treatment decisions.

PRINCIPAL CONCLUSIONS

Undergraduate decision-making was affected by academic training.

TControl: A mobile app to follow up tobacco-quitting patients

BACKGROUND AND OBJECTIVE

Tobacco smoking is a major risk factor for a wide range of respiratory and circulatory diseases in active and passive smokers. Well-designed campaigns are raising awareness to the problem and an increasing number of smokers seeks medical assistance to quit their habit. In this context, there is the need to develop mHealth Apps that assist and manage large smoke quitting programs in efficient and economic ways.

OBJECTIVES

Our main objective is to develop an efficient and free mHealth app that facilitates the management of, and assistance to, people who want to quit smoking. As secondary objectives, our research also aims at estimating the economic effect of deploying that App in the public health system.

METHODS

Using JAVA and XML we develop and deploy a new free mHealth App for Android, called TControl (Tobacco-quitting Control). We deploy the App at the Tobacco Unit of the Santa Maria Hospital in Lleida and determine its stability by following the crashes of the App. We also use a survey to test usability of the app and differences in aptitude for using the App in a sample of 31 patients. Finally, we use mathematical models to estimate the economic effect of deploying TControl in the Catalan public health system.

RESULTS

TControl keeps track of the smoke-quitting users, tracking their status, interpreting it, and offering advice and psychological support messages. The App also provides a bidirectional communication channel between patients and clinicians via mobile text messages. Additionally, registered patients have the option to interchange experiences with each other by chat. The App was found to be stable and to have high performances during startup and message sending. Our results suggest that age and gender have no statistically significant effect on patient aptitude for using TControl. Finally, we estimate that TControl could reduce costs for the Catalan public health system (CPHS) by up to € 400M in 10 years.

CONCLUSIONS

TControl is a stable and well behaved App, typically operating near optimal performance. It can be used independent of age and gender, and its wide implementation could decrease costs for the public health system.

European Society of Endodontology position statement: the use of CBCT in endodontics

This Position Statement represents a consensus of an expert committee convened by the European Society of Endodontology (ESE) on the use of Cone Beam Computed Tomography (CBCT). The statement is based on the current scientific evidence, and provides the clinician with evidence-based criteria on when to use CBCT in Endodontics. Given the dynamic and changing nature of research, development of new devices and clinical practice relating to CBCT, this Position Statement will be updated within 3 years, or before that time should new evidence become available.

Comparative accuracy of the Clearing Technique, CBCT and Micro-CT methods in studying the mesial root canal configuration of mandibular first molars

AIMS

To compare the accuracy of the clearing technique and cone beam computed tomography (CBCT) in the assessment of root canal configurations using micro-computed tomography (micro-CT) imaging system as the reference standard.

METHODOLOGY

Thirty-two mesial roots of mandibular first molars, selected on the basis of micro-CT scans (voxel size: 19.6 μm) and presenting several canal configurations, were evaluated using 2 CBCT scanners (voxels sizes: 120 μm and 150 μm) followed by the clearing technique. Two examiners analysed the data from each method and classified the anatomical configuration of the mesial canal according to Vertucci's system. Data were compared using Fisher's exact and chi-square tests. Reliability for each assessment was verified by the kappa test, and significance level was set at 5%.

RESULTS

Kappa value indicated a high level of agreement between the examiners. Detection of type I configurations was significantly lower in cleared teeth (P < 0.05), whilst type II root canals were detected in all specimens by both tests (P > 0.05). In mesial roots with variable anatomical configurations, CBCT and the clearing method were significantly less accurate than the reference standard (P < 0.05).

CONCLUSION

Within the tooth population studied, accuracy of identifying mesial root canal configuration was influenced greatly by the evaluation method and the type of anatomy. Detection of type I configurations in cleared teeth was significantly lower, whilst type II configurations were detected in all specimens by both methods. In mesial roots with variable anatomical configurations, neither CBCT nor clearing methods were accurate for detecting the actual root canal anatomy.

S-PC: an e-treatment application for management of smoke-quitting patients

The main objective of this paper is to present a new program that facilitates the management of people who want to quit smoking, implemented through an e-treatment software called S-PC (Smoker Patient Control). S-PC is a web-based application that manages groups of patients, provides a bidirectional communication through mobile text messages and e-mails between patients and clinicians and offers advice and control to keep track of the patients and their status. A total of 229 patients were enrolled in the study, randomly divided into two groups, although some variables were tested to ensure that there were no significant differences between the groups that could have an impact on the outcome of the treatment. There were no significant differences between the two groups regarding the ratio/number of males/females, tobacco dependence, co-oximetry, average cigarette consumption, current age and age when smoking started. The first group was made up of 104 patients (45.4% of the total) and followed a treatment that incorporated the S-PC tool, while the second one had 125 patients without the S-PC tool. S-PC was evaluated for its effectiveness at assisting the patients to give up smoking, and its effect on clinician time management. 74% of the S-PC group completed the treatment without relapses and remained abstinent three months after the completion of the treatment, understanding abstinence as being continuous (with no relapses allowed and co-oximetry below 1 ppm) from the day of stopping. In contrast only 45.6% of the No S-PC group completed the treatment without relapses and remained abstinent three months after completion of the treatment. The rate of admittance to the program has doubled in one year and patients went from having to wait for 3 months to be immediately admitted into the program. This therapeutic e-health program aims at maximizing the number of patients that a professional can effectively help to quit smoking. In addition, the system also detects patients who are not progressing appropriately, allowing the professional to improve their treatment parameters dynamically.

A multicentre randomized trial of combined individual and telephone counselling for smoking cessation

OBJECTIVE

The present study assessed the effectiveness of smoking cessation programs combining individual and telephone counselling, compared to individual or telephone counselling alone.

METHOD

A randomized, multicentre, open-label trial was performed between January 2009 and July 2011 at six smoking cessation clinics in Spain. Of 772 smokers assessed for eligibility, 600 (77%) met inclusion criteria and were randomized. Smokers were randomized to receive individual counselling, combined telephone and individual counselling, or telephone counselling. The primary outcome was biochemically validated continuous abstinence at 52 weeks.

RESULTS

The 52-week abstinence rate was significantly lower in the telephone group compared to the combined group (20.1% vs. 29.0%; OR, 1.32; 95% CI, 1.1-2.7) and to the individual counselling group (20.1% vs. 27.9%; OR, 1.37; 95% CI, 1.0-2.8). The 52-week abstinence rates were not significantly higher in the combined group than the individual group (OR, 0.97; 95% CI, 0.7-1.4).

CONCLUSION

Individual counselling and combined individual and telephone counselling were associated with higher 52-week abstinence rates than telephone counselling alone. A combined approach may be highly useful in the clinical treatment of smokers, as it involves less clinic visits than individual counselling alone, thus reducing the program cost, and it increases patient compliance compared to telephone counselling alone.

Managing severe curvature of radix entomolaris: three-dimensional analysis with cone beam computed tomography

AIM

To present a case of a mandibular first molar with an additional distolingual root [radix entomolaris (RE)] and to discuss the use of cone beam computed tomography (CBCT) for its identification and management during root canal treatment.

SUMMARY

A 52-year-old Caucasian woman was referred for root canal treatment of the right mandibular first molar (tooth 46). After clinical and radiographic examination, a symptomatic irreversible pulpitis was diagnosed. Three periapical radiographs with different horizontal angulations revealed the presence of an additional distolingual root. This extra root, termed RE, has an incidence of <5% in the Caucasian population. A CBCT examination was also taken, which revealed a severe root canal curvature, especially in the middle third, of this supernumerary root. CBCT provided more accurate information in terms of RE inclination and root canal curvature before commencing root canal treatment. The conventional access opening was modified into a more trapezoidal cavity, and five root canals were found. All canals were instrumented with new nickel-titanium (NiTi) files to reduce the risk of fractured instruments. After preparation, the root canals were filled using thermoplastified techniques. The 1-year follow-up periapical radiographs and CBCT images revealed a continuous periodontal space with no signs of apical periodontitis.

KEY LEARNING POINTS

• Cone beam computed tomography imaging is useful in identifying the root canal system and the surrounding structures. • An accurate detection of supernumerary roots, such as RE, can avoid complications during and after root canal treatment. • The analysis of root canal curvature is important because instrument fracture has been linked to angle and radius of curvature. • The use of new instruments can reduce the incidence of instrument fracture.