Comparative evaluation of efficacy in working length determination: Radiography versus Electronic apex locators using in vivo and ex vivo methods with stereomicroscope validation.

Background: Accurate determination of the working length (WL) is crucial for successful endodontic treatment. Various methods, including radiography and electronic apex locators (EALs), are employed for WL measurement, each with its advantages and limitations. Aim: This study aimed to compare the accuracy of WL determination using conventional radiography and the Root ZX Mini EAL against an ex vivo gold standard method. Materials and Methods: Fifty single-rooted teeth scheduled for extraction were included. WLs were determined using radiography (Grossman's method) and the Root ZX Mini EAL. An ex vivo method served as the gold standard with WL carried out on extracted teeth under a stereomicroscope. Statistical analysis included Paired samples t-test, Chi-square test, and Bland-Altman plots. Results: The mean WL values were comparable among methods, with slight variations in precision. The Root ZX Mini EAL demonstrated significantly lower mean absolute error compared to radiography (P < 0.001). Accuracy within ± 0.5 mm and ± 1 mm tolerance ranges favored the EAL over radiography (P = 0.04 and P = 0.004, respectively). Conclusion: The Root ZX Mini EAL exhibited superior accuracy and lower error rates in WL determination compared to radiography. Integrating EALs alongside radiographic techniques is recommended to optimize WL precision in clinical practice.

Comparative Assessment of Working Length Determination: Apex Locators versus Endomotor with Built-in Apex Locator in Single-Rooted Permanent Teeth.

Aim: To compare the effectiveness of Apex Locators and Endomotor with built-in Apex Locators for determining the working length in root canal treatment. Methods: A total of 120 patients were randomly assigned to three groups: Group 1 (Root ZX Mini Apex Locator), Group 2 (Minipex Apex Locator), and Group 3 (Endopilot Endomotor with built-in Apex Locator). Working length was determined using respective devices, followed by canal preparation and radiographic confirmation with a master cone. Results: There was no statistically significant difference in working length determination between Apex Locators and Endomotor with built-in Apex Locators. Acceptable working length was achieved in 105 out of 120 cases. Conclusion: The Root ZX Mini, Minipex, and Endopilot demonstrated comparable efficacy in determining working length during root canal treatment. These devices offer reliable alternatives to traditional radiographic methods, providing clinicians with accurate measurements and contributing to successful treatment outcomes.

Comparative Accuracy and Reliability of Three Electronic Apex Locators in Determining the Apical Constriction of Molar Canals: A Micro-CT Evaluation.

Background: Determining the correct apical limit for root canal treatment is essential for its success. This study evaluates the accuracy of three electronic apex locators (EALs) in locating the apical constriction (AC) in molar canals. Methods: Forty extracted human mandibular molars were scanned using micro-CT, and endodontic access cavities were created. Teeth were mounted in alginate, and three EALs-Root ZX-mini, Root ZX-II, and Sirona integrated apex locator-were used to measure the canal working length in dry canals and with EDTA gel. Micro-CT scans were performed with files in place, and the distance from the AC was calculated. Measurements within 0.1-0.5 mm were categorized as 'close'. Those extending beyond towards the major foramen were categorized as 'beyond', otherwise they were classified as 'far'. Data analysis was conducted with a level of significance set at 5%. Results: Most readings for all EALs were in the 'close' category, with significant differences between devices (p < 0.0001). Root ZX-mini and Root ZX-II had 74.4% and 72.5% 'close' readings, respectively, versus 51% for Sirona integrated. Accuracy did not differ significantly between dry and EDTA-treated canals (p = 0.306). All EALs demonstrated excellent operator reliability (ICC 0.996-1.00). Conclusions: All EALs accurately determined AC, unaffected by lubricants. However, Root ZX-mini and Root ZX-II outperformed Sirona integrated. All EALs showed consistent reliability.

Clinicians' perspectives, inducements, preferences, and clinical experiences regarding the use of electronic apex locator and apex locator integrated engine-driven instrumentation: a cross-sectional study.

BACKGROUND: This study aimed to investigate the perspectives, preferences, and clinical experiences regarding using electronic apex locator and apex locator integrated instrumentation of dentists and endodontists. METHODS: A web-based questionnaire consisting of 3 parts and 23 closed-ended questions to achieve the objective of the study was carried out in ethical conditions between August and October 2023. The first part of survey included demographic information, while the second part was about evaluating electronic apex locator usage. In the last part, only participants' use of apex locator-integrated instrumentation was evaluated. Data were analyzed at a significance level of p < 0.05. RESULTS: A total of 297 clinicians, including 59 endodontists and 34 endodontic residents/Ph.D. students participated in the questionnaire. Endodontists and endodontic residents/Ph.D. students perform statistically significantly more root canal treatments per week on average (p = 0.001). For the working length determination method (multiple option question), 78.5% of participants use an electronic apex locator and 39.7% apex locator-integrated engines. However, the preference rate for electronic apex determination technique was generally 95.6%, with the full rate confirmation of endodontists and endodontic residents/Ph.D. students (100%). A total of 21 endodontists out of 59 prefer apex locator integrated engine-driven instrumentation. Although many of these specialized clinicians use this technique, they stated that they measure electronic working length passively for confirmation of the working length before (90.5%) and after the preparation (66.7%). CONCLUSIONS: Dentists, as well as endodontists, are skeptical about apex locator-integrated engine-driven instrumentation. Using this technique as a supporter rather than a primary way for preparation within safe limits may give safer results in terms of treatment outcomes.

Effect of apical foraminal enlargement on postoperative pain and inflammatory markers in asymtomatic single-rooted mandibular teeth with apical periodontitis - An in vivo randomized controlled trial.

Aim of the Study: This study aims to assess the effect of apical foraminal enlargement on inflammatory markers and pain in patients with asymptomatic single-rooted mandibular teeth with apical periodontitis. Materials and Methods: The study included 60 patients based on inclusion and exclusion criteria. Before beginning root canal treatment (RCT), a blood sample was obtained from the antecubital fossa to evaluate the inflammatory markers, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Access opening was done and initial irrigation was done. Working length (WL) was determined with an electronic apex locator and verified with a radiograph. In the control group, the determined WL was maintained, while in the experimental group, the WL was set till the apical foramen. Biomechanical preparation was done in both groups till F2 or F3 based on the initial apical file, followed by final irrigation and obturation based on the master apical file size. Patients were given a Visual Analog Scale to record pain sensations at 24, 48, and 72 h postoperative. After 72 h, patients were recalled for follow-up appointments, and blood was taken from the antecubital fossa again to evaluate inflammatory markers. Statistical Analysis: The resultant findings for the reduction in inflammatory markers before and after RCT with or without foraminal enlargement were statistically analyzed using the Student's t-test. The pain was statistically examined with one-way "analysis of variance" and Tukey's post hoc test for inter-group comparison of pain. The level of significance was set at P < 0.05. The statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) Version 23 for Windows (SPSS Inc., Chicago, IL, USA). As pain in the control groups is zero before and after RCT, statistical analysis is not required as the overall pain score is zero. Results: The P values of the CRP and ESR of the control group were 0.02 and 0.03, respectively, which indicates it is significant whereas the P values of the ESR and CRP of the experimental group were 0.0002 and 0.0008 which indicates it is highly significant. Results indicate that the experimental group is more effective compared to the control group in reducing inflammatory markers. Pain in the control group after RCT was zero at the end of 24, 48, and 72 h. In the experimental group, where RCT was done with apical foraminal enlargement, mild pain was present at the end of 24 h which gradually decreased at the end of 48 h and no pain was reported at the end of 72 h. Conclusion: Reduction in inflammatory markers was more effective in RCT with apical enlargement than without apical enlargement. RCT with apical enlargement caused mild pain in the patients immediately after treatment which gradually decreased over time.

Effect of Different Electroconductive Root Canal Irrigations on the Accuracy of Different Apex Locators: An In Vitro Comparative Study.

Aim: An accurate working length (WL) estimation is fundamental to a successful endodontic therapy. The objective of this comparative in vitro research was to investigate the performance of iPex II and the Root ZX Mini electronic apex locators (EALs) in measuring root canal WL with different irrigant solutions and their relation to the electrical conductivity of irrigation solutions. Materials and Methods: Seventy sound permanent lower premolar teeth, each with a single root and developed apices, were used. Under an X15 stereomicroscope, the real working length was determined with the aid of a #10 file. After that, teeth were placed into an alginate model, and the iPex II and Root ZX Mini were used for the detection of electronic working length with various irrigants. Seventy teeth were randomly distributed into seven groups, 10 per each group (group I: dry canal; group II: distilled water; group III: ozonated water; group IV: 5% sodium hypochlorite (NaOCl); group V: 2% chlorhexidine, group VI: 17% ethylenediaminetetraacetic acid (EDTA) solution, and group VII: 17% EDTA gel). The difference in WL was calculated by deducting real working length from its electronic working length. The study also evaluates the electrical conductivity of the seven endodontic irrigant solutions. The two-way analysis of variance (ANOVA) test was used for statistical analysis. Results: Statistically, neither both types of EALs (P = 0.088) nor various irrigating solutions with varying electrical conductivities (P = 0.099) significantly affect the accuracy of EL estimation. Conclusions: There were no significant differences between the accuracy of the Root ZX Mini and the iPex II. The accuracy of both apex locators is unaffected in the presence of various irrigation solutions with varying electrical conductivities in this research.

Comparative evaluation of the accuracy of two electronic apex locators in detecting simulated incomplete vertical root fractures: An in vitro stereomicroscopic study.

Aim: The aim of this study was to compare the accuracy of two different electronic apex locators (EALs) in detecting simulated incomplete vertical root fractures (VRFs). Materials and Methods: Thirty freshly extracted single-rooted teeth were randomly divided into three groups of 10 teeth each labeled as Groups A, B, and C. Incomplete VRFs were simulated in the coronal, middle, and apical one-third of the roots for Groups A, B, and C, respectively. The teeth were embedded in alginate mold and fracture location was determined with Root ZX and Propex EALs for each sample and each group. To calculate the actual length (AL), each sample was sectioned at the upper level of the vertical fracture, and the length was measured by setting the stopper of the #10 K file under a stereomicroscope at ×30 magnification. The electronic lengths and ALs were compared using computer software, and the results were analyzed using SPSS 28.0 at a 95% confidence level. Results: No significant differences were seen in the accuracy of the two EALs when compared with ALs. Root ZX showed significantly longer measurements than ALs in groups B and C. Conclusion: The tested EALs showed low accuracy (20%) in detecting simulated incomplete VRFs with a tendency for longer measurements compared to ALs.

The Accuracy of Cone Beam Computed Tomography Scans in Determining the Working Length in Teeth Requiring Non-surgical Endodontic Treatment: A Retrospective Clinical Study.

BACKGROUND: Endodontic treatment aims to eradicate both microbial infection and inflammatory processes within the root canal space as well as in the periapical (PA) region of the tooth. To achieve this, the canals should be cleaned, shaped, disinfected, and obturated to the proper working length. Clinically, the working length is described as the measurement from the coronal reference point to the physiological apex located at the apical foramen. In the available literature, electronic apex locators (EAL) with periapical (PA) radiographs are the most reliable and precise tools for determining the working length in routine root canal treatment. Therefore, the aim of this retrospective clinical study is to evaluate if cone beam computed tomography (CBCT) scans are reliable and accurate in measuring endodontic working length compared to standard clinical measurement methods. METHODS: Patients who fit the inclusion criteria were identified. A postgraduate endodontic resident blinded to the cone beam computed tomography scan results treated all teeth in the field of view that needed endodontic treatment. The root canal length was determined using J Morita Root ZX II apex locator (J Morita Corp., Kyoto, Japan) and periapical radiographs. The dental radiology specialist interpreted the pre-existing cone beam computed tomography (CBCT) scan images and determined the working length. Statistical comparisons of the working length measurements of EAL and CBCT were performed using paired sample t-tests after verifying normality. RESULTS: No statistically significant differences in the working lengths were found in all canals with the exception of the palatal canal only (t=2.16, p=0.034), suggesting consistent measurements between EAL and CBCT. CONCLUSION: In teeth requiring endodontic treatment, pre-existing cone beam computed tomography scan images are accurate as electronic apex locators when determining the working length. A limitation of this study is that it only includes a limited number of samples and is affected by operator variation.

Efficacy of electronic apex locators in comparison with intraoral radiographs in working length determination- a systematic review and meta-analysis.

BACKGROUND: Successful endodontic treatment needs accurate determination of working length (WL). Electronic apex locators (EALs) were presented as an alternative to radiographic methods; and since then, they have evolved and gained popularity in the determination of WL. However, there is insufficient evidence on the post-operative pain, adequacy, and accuracy of EALs in determining WL. OBJECTIVE: The systematic review and meta-analysis aims to gather evidence regarding the effectiveness of EALs for WL determination when compared to different imaging techniques along with postoperative pain associated with WL determination, the number of radiographs taken during the procedure, the time taken, and the adverse effects. METHODS: For the review, clinical studies with cross-over and parallel-arm randomized controlled trials (RCTs) were searched in seven electronic databases, followed by cross-referencing of the selected studies and related research synthesis. Risk of bias (RoB) assessment was carried out with Cochrane's RoB tool and a random-effects model was used. The meta-analysis was performed with the RevMan software 5.4.1. RESULTS: Eleven eligible RCTs were incorporated into the review and eight RCTs into the meta-analysis, of which five had high RoB and the remaining six had unclear RoB. Following meta-analysis, no significant difference in postoperative pain was found among the EAL and radiograph groups (SMD 0.00, CI .29 to .28, 354 participants; P value = 0.98). Radiograph group showed better WL accuracy (SMD 0.55, CI .11 to .99, 254 participants; P value = 0.02), while the EAL group had 10% better WL adequacy (RR 1.10, CI 1.03-1.18, 573 participants; P value = 0.006). CONCLUSION: We found very low-certainty evidence to support the efficacy of different types of EAL compared to radiography for the outcomes tested. We were unable to reach any conclusions about the superiority of any type of EAL. Well-planned RCTs need to be conducted by standardizing the outcomes and outcome measurement methods.

Comparative Evaluation of Different Apex Locators as a Diagnostic Tool to Detect Root Perforations: An In Vitro Study.

Aim: The purpose of this study was to determine how effectively four distinct apex locators could diagnose root perforations in terms of accuracy and repeatability. Materials and Methods: Eighty mandibular premolars with a single root were instrumented. The distal face of the root was perforated at both the apical and middle thirds, five millimeters from the apical terminus. K-files connected to apex locators were used for detection on teeth set in an alginate-filled box. Results: The current research showed that all four apex locators accurately detected root canal perforations. Conclusion: This study's findings show that all four apex locators were able to accurately and successfully identify root canal perforations.

Comparative evaluation of accuracy of working length determination with fifth-generation apex locator using two different techniques: An in vitro study.

Context: Accurate working length (WL) determination is essential for successful root canal therapy. Aim: The aim of this study was to compare the difference between two different techniques in locating minor constriction using fifth-generation electronic apex locator. Settings and Design: A detailed protocol explaining the procedures of the study was submitted to the institutional ethics committee. Subjects and Methods: Forty extracted human permanent canine teeth were selected. WL was measured three times for each sample by three different examiners for both the conventional and experimental techniques at different time intervals. Interexaminers were blinded to their measurements, and the person who analyzed mean value was also blinded with techniques. Finally, radiographic working length was obtained using 15 size K-file. A size 20 K-file was cemented into the measured position with glass ionomer cement. Each tooth was viewed under a stereomicroscope at ×40 magnification. The distance from the file tip to the root apex was measured and calibrated to the nearest tenth of a millimeter. Statistical Analysis Used: Using Stata statistical software (Version 17, Statacorp, College Station, Texas, USA). The agreement between raters and techniques was determined using intraclass correlation coefficient "ICC" and Bland-Altman plot. Results: The "experimental method" (0.95, 95%) showed better agreement between the raters in comparison with the "conventional method" (0.93, 95%). Conclusions: The experimental technique showed perfect agreement between examiners in locating the minor constriction of the apical foramen.

A Global Overview on Electronic Apex Locator Use From 1968 to 2023: A Bibliometric Analysis.

INTRODUCTION: This bibliometric review analyzed the research trends and main characteristics of articles related to Electronic Apex Locators (EALs). METHODS: The search was conducted in November 2023 on the Web of Science Core Collection. Narrative and systematic reviews, observational and intervention studies, laboratory, and clinical studies were included. Two researchers selected the articles and extracted the number of citations, year of publication, journal, study design, theme, country, continent, institutions, author, and keywords. Collaborative networks were generated using the VOSviewer software. The relationship between data were determined by Spearman's correlation. RESULTS: The search resulted in 374 articles, of which 294 were included. Most cited article had 175 citations. The most prevalent journal was the Journal of Endodontics (n = 84). The predominant study design was the laboratory-based (n = 223). The predominant theme was the EALs accuracy (n = 175). Piasecki L was the author with the highest number of articles (n = 11). Only 8.16% of the studies were conducted in deciduous teeth. The country with the most studies was Brazil (n = 46). Asia (n = 107) was the continent with the highest number of publications. There was a weak positive correlation between the number of citations and impact factor (rho = .294), and a strong negative correlation between citations and year of publication (rho = -.710). CONCLUSIONS: The majority of articles were laboratory-based studies conducted on permanent teeth, focusing on the accuracy of EALs. Future studies should prioritize research on deciduous teeth, systematic reviews, and, notably, clinical trials.

An Ex-Vivo Study Comparing the Accuracy of the E-Connect S+ and Morita Tri Auto ZX2+ Endodontic Handpieces in Root Canal Length Determination.

INTRODUCTION: This ex vivo study evaluated the accuracy of the Electronic Apex Locator (EAL) and Automatic Apical Stop (AAS) functions of the E-Connect S+ and Morita Tri Auto ZX2+ cordless apex locators in determining patency length. METHODS: Sixty-four human teeth with a single root were randomly allocated into E-connect or Morita groups (n = 32). The canals were accessed and preflared, after which a size 15 K-file was inserted into the canal to the major foramen and recorded as the actual length (AL). Matched measurements were taken using the AAS and EAL functions and visually confirmed with confocal microscopy. The variance between canal length (mm), the persons correlation (ρ) between function and AL, and the accuracy (%) of the canal length relative to the AL (Δmm) between devices and functions were assessed. RESULTS: Regardless of device or function, all measurements were within 1±Δmm and correlated strongly (ρ > 0.97) with the AL. When considering a more stringent clinically acceptable range of 0.5±Δmm from the AL, all devices and functions demonstrated similar accuracy levels (84%-94%). However, at lower tolerance ranges, the E-connect device with the EAL function exhibited the highest accuracy. On average, all devices and functions stopped short of the AL (mean Δmm>0). CONCLUSION: The E-Connect S+ and Morita Tri Auto ZX2+ apex locators provided reliable accuracy in determining the position of the major foramen. These findings demonstrate a high level of reproducibility in canal length measurements using both cordless endodontic handpieces, regardless of whether the EAL or AAS functions were employed.

Comparative evaluation of digital radiography, electronic apex locator and simultaneous working length determination on postoperative pain after root canal treatment: a randomized clinical trial.

Purpose: The study aimed to compare postoperative pain after root canal preparation using three different methods of working length determination. Materials and methods: 60 patients diagnosed with symptomatic irreversible pulpitis were randomly divided into three groups based on the method of working length (WL) determination. Group 1: digital radiograph (DRG), Group 2: electronic apex locator (EAL), Group 3: the simultaneous working length control (SLC) method using an endomotor with an integrated apex locator. The root canal treatments were completed in a single visit, and patients were asked to record their pain response using the Visual Analog Scale (VAS) at 6, 24, 48, and 72 hours postoperatively. Results: Group 1 (DRG) recorded the highest postoperative pain score, while the lowest was recorded by Group 3 (SLC). There was a statistically significant difference in the VAS pain scores between DRG and SLC (p<0.05) at 6-, 24- and 48-hour intervals. Conclusion: Within the limitations of this study, it can be concluded that the SLC can be a helpful working length determination technique to reduce postoperative pain.

Can ultrasonography be used to determine working length in endodontic treatment? An in vitro study.

This study was conducted to evaluate efficacy of ultrasonography (USG) in determining working length in in-vitro conditions. Twenty five access cavities of maxillary incisor teeth were opened and actual working lengths (AWL) were measured with dental operating microscope. The working length were then measured with an electronic apex locator and USG. USG and apex locator measurements were statistically analyzed using one sample t-test and compared with AWL. The mean AWL measurment was 20.68 mm. USG measured the working length slightly longer (21.09 mm) than the measurements of apex locator (20.64 mm). Statistical analysis showed that the USG method provided similar measurements to electronic apex locators and with no statistical difference with actual working length (P < .05). USG emerges as a promising method for working length measurement that allows simultaneous visualization of root tip anatomy in cases where electronic apex locators may be insufficient and there is buccal cortical bone loss.

Evaluation of changes in root canal length and accuracy of the electronic apex locator during different stages of endodontic treatment and retreatment.

This study evaluated changes in the root canal length (RCL) and the accuracy of the electronic apex locator (EAL) during the different stages of endodontic treatment and retreatment. Fifty-six mesial root canals of mandibular molars were selected. The actual root canal length (AL) of the canals was obtained by inserting a size 15 hand file up to the apical foramen, under magnification. The electronic lengths were obtained at the "APEX" mark of Root ZX II, using an alginate model. Both measurements were performed at three different stages of the initial root canal treatment-unflared, flared, and concluded-and at two stages of retreatment, after achieving patency and repreparation. Data were statistically analyzed and the significance level established was 5%. All stages produced a significant reduction in the AL (p < 0.05). The greatest variation was observed between the unflared-flared stages (0.2 mm) and between concluded-patency stages (0.09 mm), with no difference between them (p > 0.05). The accuracy of Root ZX II was negatively affected after achieving patency, presenting statistically significant difference compared to the other stages (p < 0.05). A significant reduction in the RCL was observed along the different stages of endodontic treatment and retreatment. The EAL was accurate to measure the root canals in most stages, except after achieving patency for endodontic retreatment. Determining and monitoring the RCL is an essential step towards a favorable prognosis, since it reduced along the different stages evaluated. Root ZX II was not accurate for endodontic retreatment.

Influence of Embedding Medium on iPex Electronic Apex Locator Accuracy: An Ex Vivo Comparative Study Using Alginate, Saline, and Gelatin Models.

AIM: Accurate working length determination during root canal treatment is essential for achieving successful outcomes. This study aimed to evaluate the impact of embedding medium on the accuracy of iPex electronic apex locator (EAL). MATERIALS AND METHODS: Sixty-one extracted single-rooted teeth were decoronated and coronally flared with Gates-Glidden burs. Actual canal length (ACL) was obtained by introducing a size 8 K-file until its tip reached the most coronal border of the apical foramen. This step was performed thrice and then averaged. Deducting 0.5 mm from the ACL provided the working length (WL). The teeth were randomly placed in plastic containers filled with freshly mixed alginate, gelatin, or saline, with the lip clip placed in the medium. The blinded operator obtained electronic measurements using iPex by advancing a K-file with a size compatible with the canal attached to the file clip and advanced until the 0.0 mark, then withdrawn to the 0.5 mark. This step was performed thrice and then averaged. Data were analyzed using ANOVA and Tukey's post hoc test, with significance level set at 5% (α = 0.05). RESULTS: The mean difference between WL and iPex length obtained in the gelatin model was significantly longer than the difference with mean iPex length in alginate (p = 0.005) and in saline (p < 0.001). There was no significant difference between iPex readings obtained in alginate and saline (p = 0.249). CONCLUSION: The use of freshly mixed alginate or saline for ex vivo assessment of iPex is recommended, whereas the use of gelatin could increase the chances of readings longer than looked for. CLINICAL SIGNIFICANCE: Identifying the optimum embedding medium for ex vivo testing of EALs permits the comparison and assessment of several factors affecting EALs' precision under standardized conditions. This helps in understanding EAL performance in vivo and in optimizing its clinical utilization.

The Effect of Coronal Pre-flaring and Type of Root Canal Irrigation on Working Length Accuracy Using Electronic Apex Locators.

Background: Successful root canal treatment is influenced by the apical extent of root canal preparation and the eventual root canal filling. Achieving the full working length until the apical constriction, which is usually 0.5 - 1 mm shorter than the anatomical apex, is crucial. Electronic apex locators were used to detect the working length more accurately. There are six generations of electronic apex locators in the market. The selection of the appropriate irrigation with each apex locator for accurate working length determination is not fully investigated. Methods: The actual working lengths of 120 freshly extracted human single-rooted teeth were measured and compared with their working lengths using 3 rd generation (Root ZX) followed by 6 th generation (Raypex 6) apex locators in dry medium, presence of 5.25% sodium hypochlorite, and 2% chlorhexidine, without coronal pre-flaring and after coronal pre-flaring using the same irrigating media. Data were collected, tabulated, and afterward analyzed using one-way ANOVA with post-hoc to evaluate the significant difference in average working length between actual working length, Root ZX, and Raypex 6 apex locator working lengths accuracy. Results: The significant results were shown in roots that were coronally pre-flared and their working lengths were measured in a dry medium using Raypex 6 apex locator. While using the Root ZX apex locator, the most accurate results were shown in roots that were coronally pre-flared and their working lengths were measured while using a chlorhexidine irrigating solution. Conclusions: It is concluded that it is very important to know the specific irrigating medium to be used with each specific electronic apex locator to achieve the most accurate working length results.

Accuracy of Root ZX Electronic Apex Locator in Relation to Two Different Employment Protocols: An In Vitro Study.

Objective The aim of this study is to determine the apical level of the root canal, whether it is the apical foramen or a level coronal to it, that Root ZX (J. Morita Co., Kyoto, Japan) targets and to identify its employment protocol that provides better accuracy. Methods Actual lengths (ALs) of 75 extracted single-rooted teeth were obtained by inserting a K-file size 8 until its tip was in level with the most coronal border of the apical foramen. Reference length (RL) was calculated by deducting 0.5 mm from AL. Roots were placed in porous sponge block soaked with Ringer's solution, and canals were irrigated with 2 mL of 5% sodium hypochlorite. The blinded operator used Root ZX to measure lengths with K-file size 8. In the first tested employment protocol, the file was advanced to the "APEX mark" of the digital display, and the length was obtained. The second employment protocol followed the manufacturer's recommendations by inserting the file until the "APEX mark" followed by its withdrawal to the "0.5 mark." Stability of the digital meter for 5 seconds was mandatory before recording the lengths. All measurements were repeated one week later and then both measurements were averaged to represent "APEX mark" and "0.5 mark," respectively. Data were analyzed using t-test, with significance set at 0.05. Results Regardless of the employment protocol, most registered lengths were longer than targeted. The mean "APEX mark" was significantly longer than the mean AL (P=0.000), and the mean "0.5 mark" was significantly longer than the mean RL (P=0.000). Although the mean "0.5 mark" was longer than the mean AL, the difference was not significant (P=0.07). Conclusion The apical level of the root canal targeted by the Root ZX was the apical foramen. The most accurate employment protocol to achieve that is to use the Root ZX according to the manufacturer's recommendations.

In Vitro Comparison of the Accuracy of Cone-Beam Computed Tomography Scanning and Electronic Apex Locators in Detection of Simulated Root Perforations in Different Localizations.

INTRODUCTION: This study aimed to compare the accuracy of cone-beam computed tomographic (CBCT) scanning and 2 different electronic apex locators (EALs) in the detection of simulated root canal perforations in different localizations. METHODS: Eighty human mandibular premolars were prepared and divided into 2 groups according to the localization of the perforation area, having a 1-mm diameter. The distance between the occlusal edge and the beginning of the perforation was measured under a stereomicroscope (actual working length) using 2 EALs (Propex II [Dentsply Maillefer, Ballaigues, Switzerland] and Dentaport ZX [J. Morita, Tokyo, Japan]) (electronic working length) and CBCT images (CBCT working length). The calculations were made by subtracting the actual working length from the electronic working length and the CBCT working length to determine the differences. RESULTS: In the apical third perforation group, there was a significant difference between Dentaport ZX and CBCT imaging. There was no significant difference between Dentaport ZX and Propex II and Propex II and CBCT measurements. In the middle third perforation group, Propex II was significantly more successful than CBCT imaging. In addition, there was no significance between the accuracy of Propex II in detecting the perforation area between the apical third perforation group and the middle third perforation group. CBCT imaging was more accurate in detecting the perforation area in the apical third perforation group than in the middle third perforation group. CONCLUSIONS: In cases in which the root canal perforation was in the apical third of the root, both the EAL and CBCT imaging were successful in determining the perforation area, whereas the success rate of all devices used in this study decreased when the perforation area was in the middle third of the root.