Ex vivo accuracy of three electronic apex locators: Root ZX, Elements Diagnostic Unit and Apex Locator and ProPex

The usefulness of ultrasonography as a dynamic measurement system for visualizing root canal working length: an in vivo study

OBJECTIVE

Although apex locators are generally effective tools for determining root canal working length, they may produce inaccurate results in some cases. The present study aimed to evaluate the efficacy of ultrasonography as an alternative method for measuring root canal length.

MATERIALS AND METHODS

Forty-seven anterior teeth with apical lesions were selected for the study. Initially, an electronic apex locator was used to measure the working length. Subsequently, ultrasonography was employed to visualize the root apex and determine the working length. During ultrasound imaging, a K-file No. 15 was inserted into the root canal until its tip was visible on the ultrasound monitor. Measurements obtained from both methods were compared using an independent sample t-test. Correlations were assessed with the Pearson correlation coefficient, and agreement was determined using the Bland‒Altman plot.

RESULTS

The mean working canal length was 19.9 mm for the apex locator and 20.6 mm for the ultrasonography-guided method. No significant differences were observed between the data obtained using the apex locator method and the data obtained using the ultrasonography guidance method. Furthermore, a high level of agreement was identified between the two techniques.

CONCLUSION

Ultrasonography can be used to visualize the apex effectively and determine canal length, especially when canal length determination is uncertain for various reasons.

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.

Accuracy of an Electronic Apex Locator (EAL) in Measuring the Working Length of Root Canals in Comparison With Radiographs: An In Vivo Study

INTRODUCTION

Traditionally, radiographs were used to assess the working length of root canals. However, the use of Electronic Apex Locators (EAL) may be a non-invasive alternative. This study aimed to evaluate the accuracy of the electronic apex locator (EAL) compared to radiographic measurements in determining the working length of root canals.

METHOD

The study assessed the performance of EALs in different scenarios, including the presence of blood and pulp tissue, the use of ethylenediaminetetraacetic acid (EDTA), sodium hypochlorite (NaOCl) as an irrigant, and post-instrumentation with normal saline. An electronic apex locator (DTE DPEX-V; Woodpecker, China) was used alongside traditional radiographs to measure the working length in 144 root canal treatments. Bland-Altman analysis was used to compare the measurements between EAL and radiographs using Jamovi software, v2.4.8 (https://www.jamovi.org/).

RESULT

The findings revealed strong correlations between EAL and radiographic measurements across all testing environments, with Pearson's correlation coefficients ranging from 0.944 to 0.998. The Bland-Altman analysis suggests bias; the average difference was negative and close to zero (Pulp: -0.354, EDTA: -0.0972, NaOCl: -0.0382, Saline: -0.0139) when EAL measurements were compared to radiographic measurements.

CONCLUSION

The working length measurement of root canals using an electronic apex locator such as DTE DPEX-V is comparable to traditional radiographic measurements. The use of irrigants improves the measurement. The EAL has the potential to be an alternative to the invasive radiograph for root canal length measurement.

Alameer S, Aldossary A, Almutairi W, N. Almaliki M, A. Farooqi F, Taymour N. 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.

Evaluation of Different Techniques of Working Length Determination in Comparison with CBCT

AIM

To estimate the working length of teeth using conventional tactile technique, radiovisiography technique, Apex locator, and confirmation of working length by cone beam computed tomography technique.

MATERIALS AND METHODS

Forty patients with the age group between 20 and 50 years with irreversible pulpitis were included in this study. After taking a preoperative radiograph, the procedure was started. The cavity wall buildup was done using composite in the cases needed and then rubber dam application was done. The working length of mesiobuccal and mesiolingual canal was taken using cone beam computed tomography and this was considered as the standard value. Then using tactile method, length of the canal was measured using radiovisiographic software followed by apexlocator.

RESULT

The Apex locator has showed best result as compared to tactile and radiovisiography.

CONCLUSION

Apex locator values were closest to cone beam computed tomography working length measurement values and electronic apexlocator can be used efficiently as an alternative method for working length determination. The quality of various techniques according to ranks of working length determination was found to be Cone beam computed tomography (CBCT) > Apexloc > Radiovisiography (RVG) > Tactile. Thus, Apex locator can be used as an alternative to cone beam computed tomography for working length determination.

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.

In Vitro Evaluation of the Accuracy of Three Electronic Apex Locators Using Different Sodium Hypochlorite Concentrations

Background and Objectives: The aim of this study was to compare the accuracy of three types of electronic apex locators (EALs) when two different concentrations of NaOCl irrigation solutions are used by two operators. Materials and Methods: After creating the access cavities for 20 single rooted extracted teeth, the actual canal length (ACL) of each canal was determined visually using a #10 file and magnification. The teeth were subsequently inserted in plastic molds filled with alginate. The electronic measurement of root canal length (EWL) was performed using three different electronic apex locators: Root ZX II, Apex ID, and Dual Pex. Two independent operators, an endodontic specialist with 20 years practice and an undergraduate student in the final year of study, performed the irrigation procedures with two different concentrations of NaOCl (2% and 5.25%), and then measured the EWL using each of the EALs. The accuracy of all EALs, was determined in each case by subtracting the EWL from the ACL. Statistical analyses were performed using one-way ANOVA test. Results: In the presence of 2% NaOCl solution, for a margin error of ±0.5 mm, Root ZX II, Apex ID, and Dual Pex presented an accuracy of 90%, 80%, and 85% respectively. The increase in the concentration of the irrigation solution affected the accuracy of Root ZX II and Apex ID for both operators, diminishing it to 75% for the same margin error, but improved Dual Pex's accuracy to 100%. Conclusions: The best accuracy in working length determination was obtained by Root ZX II for 2% NaOCl solution and by Dual Pex for 5.25% NaOCl solution with no significant statistical difference when compared.

Accuracy of working length measurement by Raypex 6: Electronic apex locator versus actual measurements under stereomicroscope

Background/Aim: This study aimed to evaluate the precision of the Raypex 6 apex locator in locating the apical constriction (AC) and major foramen (MF) during a root canal treatment compared with a microscopic evaluation. Another aim of the present study was to evaluate the accuracy of the Raypex 6 in the presence of different irrigating solutions (NaOCl, saline, EDTA, etidronic acid-HEBP). Material and Methods: One hundred and nine patients were included in this study and were randomly assigned into four groups according to the irrigation solution used; NaOCl, EDTA, HEBF and saline. Electronic MF (EMF) and AC (EAC) were measured by using Raypex 6. The teeth were extracted. The apical 3 mm of each canal was trimmed to expose the file tip. The samples were observed under a stereomicroscope, and the actual length of MF (ALMF) and AC (ALAC) were measured. The data were analyzed by using x2 test, and significance was set at P< 0.05. Results: The Raypex 6 was accurate 71.4% of the time to ±0.5mm and 93.3% of the time to ±1mm in determining the ALAC. While similar ALAC-EAC differences were observed in EDTA, NaOCl, and saline groups (p= 0.230), the highest differences were seen in the HEBP group (p= 1.000). The precision of Raypex 6 in determining the working length measurement depends on the type of irrigation. All solutions allowed reliable detection of AC. However, HEBF significantly increased the risk of overpreparation. Conclusions: Raypex 6 can be recommended for clinical use and its accuracy is not affected by the type of irrigant when locating MF.

The accuracy of two electronic apex locators on effect of preflaring and file size: An in vitro study

Aim:

This study was conducted to evaluate the effect of preflaring and file size on the accuracy of the Root ZX and E-PEX Pro electronic apex locators (EALs).

Materials and Methods:

The actual working length was set 1 mm short of the apical foramen in the forty extracted mandibular premolars. The teeth were embedded in an alginate mold, and two examiners performed the electronic measurements using #10, #15, and #20 K-files. The files were inserted into the root canals until the “0.0” or “APEX” signals were observed on the light-emitting diode or display screens for the E-PEX Pro and Root ZX, respectively, retracting to the 1.0 mark. The measurements were repeated after the preflaring using the S1 and SX Pro-Taper instruments. The mean differences between the actual length and electronic length values were analyzed by the Wilcoxon signed-ranked test with a significance level of P < 0.05. The factors evaluated were “Accuracy of EALs,” “size of file,” and “presence of preflaring.

Results:

No significant differences were observed in the accuracy of both EALs when compared with the actual lengths. On the size of the file, significant difference noticed with #20 K-file. The preflaring procedure significantly (P < 0.05) increased the accuracy of the measurements for the Root ZX and Epex Pro.

Conclusions:

The tested EALs showed acceptable accuracy, whereas the preflaring procedure revealed a more significant effect than the used file size.

Apexoconnection: A Novel Technique to Determine Working Length

Purpose

The aim of this study was to evaluate and compare the accuracy of working length (WL) determination when using the conventional electronic WL (EWL) technique versus using the novel Apexoconnection technique involving EWL with a connector (EWLc).

Materials and Methods

Sixty extracted posterior teeth with a total of 118 root canals were selected for the study. The real WL (RWL) of each canal was verified using a dental microscope under 25.6x magnification. Root canal lengths were measured with an apex locator using the attachment device directly attached to the hand file in the root canal and then adding another hand file as a connector between the attachment device and the file in the root canal. The distance from the file’s stopper to its tip was measured using a digital caliper. Statistical analysis was carried out to analyze the data between experimental groups.

Results

The results of the statistical test showed that the differences in the WL determined by either technique and the proper length as determined under the microscope were not statistically significant. The results of the statistical test comparing the groups were also not statistically significant.

Conclusion

In this in vitro study, both the novel and conventional techniques were equally accurate for determining WL when compared with the RWL.

Influence of embedding media on the accuracy of working length determination by means of apex locator: an ex vivo study

The aim of this research was to determine ex vivo the influence on accuracy of five different embedding media, for investigative and educational purposes, and one electronic apex locator. 110 human extracted mature roots of permanent single-rooted human teeth were used. The roots were embedded in alginate, stick sponge, 2% agar–agar and 6% and 12% gelatin. The actual working length to the physiological foramen was determined under a stereo-microscope (16 ×) and the electronic working lengths with the Elements Diagnostic Unit and a K-file ISO 10. The accuracy ranges of the accumulated measurements, when allowing a ± 0.5 mm tolerance, went from 98.2% (6% and 12% gelatin), 93.7% (alginate), 92.8% (2% agar–agar) to 91.7% (sponge). The exact measurements at the physiological foramen ranged from 80.0% (6% gelatin), 76.5% (2% agar–agar), 71.8% (12% gelatin), 68.2% (alginate) to 64.5% (sponge). Although relatively seldom (n = 24), measurements with deviations of more than ± 0.5 mm were also observed; thus, the accuracy of the working length determination results per se can be considered as clinically acceptable. The results of this research allow a recommendation of the investigated embedding media for electronic working length determination models for educational and research purposes in endodontics.

Comparison of Accuracy of Apex Locator with Tactile and Conventional Radiographic Method for Working Length Determination in Primary and Permanent Teeth

Background

Correct working length determination is one of the main factors leading to success in root canal treatment. The digital tactile sense technique and conventional radiography (CR) are common techniques for working length determination but both techniques have some limitations. A newer method of working length estimation involves use of the apex locator. The current study was carried out to compare the accuracy of the apex locator with a tactile and conventional radiographic method for working length determination in primary and permanent teeth.

Materials and methods

The study was conducted on 60 children selected randomly from the outpatient department of the Department of Pediatric and Preventive Dentistry. The patients were divided into two groups: primary and permanent. An informed consent was obtained. After radiographic confirmation of the presence of more than two-third root length access, opening was done in all the teeth. The pulp was extirpated completely from the chamber and canals. Canals were dried completely using paper points. Working length was determined by all the three methods, i.e., digital tactile method, apex locator, and conventional intraoral periapical radiographic method in both primary and permanent teeth.

Results

The data were coded and entered into the Microsoft Excel spreadsheet. The analysis was done using the SPSS version 20 (IBM SPSS Statistics Inc., Chicago, Illinois, USA) Windows software program. The variables were assessed for normality using the one-way ANOVA test. Within the limitations of this study, working lengths obtained by the tactile method, the apex locator, and the radiographic method were comparable. There was no statistically significant difference among the three methods except in mesiolingual and distobuccal canals of permanent teeth.

Conclusion

The apex locator can serve as a useful guide to determine the working length in permanent as well as primary teeth.

How to cite this article

Rathore K, Tandon S, Sharma M, et al. Comparison of Accuracy of Apex Locator with Tactile and Conventional Radiographic Method for Working Length Determination in Primary and Permanent Teeth. Int J Clin Pediatr Dent 2020;13(3):235-239.

Evaluation of the accuracy of different apex locators in determining the working length during root canal retreatment

Background. This study aimed to assess the accuracy of three electronic apex locators (EALs) (Dentaport ZX [J Morita, Tokyo, Japan], Propex Pixi [Dentsply Maillefer, Ballaigues, Switzerland], and iPex II [NSK, Tokyo, Japan]) during root canal retreatment. Methods. The root canal lengths of 90 extracted single-rooted human teeth were determined under a dental operating microscope at ×10 magnification. The actual working length (AWL) was 0.5 mm less than the root length. Electronic measurements were performed with the three EALs. The root canals were instrumented and filled to the actual working length using the lateral compaction technique. After seven days, the teeth were retreated until the retreatment file was applied to the root canal at the working length determined by EALs, and then, the three EALs were used for determining the retreatment working length. Data were analyzed using chi-squared and Kruskal-Wallis tests. Results. In the retreatment, the accuracy of EALs was reported at %83.3 for Dentaport ZX, %83.4 forPropex Pixi, and %80 for iPex II within a tolerance of 0.5± mm of the AWL. Conclusion. Under the limitations of this study, Dentaport ZX, Propex Pixi, and iPex II can be a useful adjunct during retreatment. Clinicians should be aware that residual materials in the root canal during retreatment can affect the accuracy of EALs.

The influence of two forms of chlorhexidine on the accuracy of contemporary electronic apex locators

Background

Accurate determination of working length (WL) is crucial for the success of endodontic therapy. The aim of this study was to determine the influence of 2% chlorhexidine digluconate solution, 2% chlorhexidine digluconate gel and 2% hypochlorite solution on the accuracy of two devices: the Raypex 5 and the ApexDal.

Methods

Twenty-nine single-rooted human teeth were used in this study. The crowns were cut horizontally and embedded in an alginate mass. In each tooth, six endodontic measurements were made using two electronic apex locators (EALs): a Raypex 5 and an ApexDal. For each EAL, measurements were taken with the following products: 2% chlorhexidine solution (CHX-S group), 2% chlorhexidine gel (CHX-G group) and 2% NaOCl (NaOCl group). After performing an endodontic measurement, the endodontic instruments were stabilized with flow resin composite. Afterwards, the roots were removed from the alginate mass, and the apical one-third of each root was cut lengthways to recover the canal system. Last, the distance between the file tip and the apical foramen was measured under a microscope at 60 x magnification.

Results

Statistically significant differences were found between CHX-S and NaOCl and CHX-G and NaOCl, but no significant differences were detected between CHX-S and CHX-G during the testing of both devices. No statistically significant differences were observed between the Raypex 5 and ApexDal for all intracanal media tested.

Conclusion

The EALs Raypex 5 and ApexDal had higher accuracy in the anatomical foramen of the root containing chlorhexidine in the gel or in the solution form than in the canal containing sodium hypochlorite.

Comparison of Accuracy in Determining the Root Canal Working Length by Using Two Generations of Apex Locators - An In Vitro Study

AIM

The present in-vitro study aims to compare the accuracy of root canal working length determination between the third generation and fourth generation electronic apex locators.

MATERIAL AND METHODS

Fifty extracted single-rooted single canal teeth were selected for the study, and a definite coronal plane was prepared. Actual working length (AL) was measured using a stereomicroscope under 8X magnification. Electronic working length measurements were recorded using Root ZX (EL1) and Elements Diagnostic Unit (EL2) apex locators. One-way ANOVA test was carried out to analyse the data among the experimental groups.

RESULTS

The results of the one-way ANOVA test showed that difference in the working length determined by either apex locators (EL1 and EL2) and actual length determined under a stereomicroscope (AL) was statistically not significant. The independent 't' test comparing between groups EL1 and AL; and EL2 and AL showed that working length determined by either of the apex locators (EL1 and EL2) and actual length determined under a stereomicroscope (AL) was statistically not significant.

CONCLUSION

In this in vitro study, the Root ZX and Elements Diagnostic Unit apex locators are equally accurate for determination of working length when compared to actual working length.

In vitro Evaluation of the Accuracy of the Root Zx in the Presence of Naocl 2.5% and Chlorhexidine 0.2

Background

Establishing the working length at the apical constriction is considered ideal for root canal therapy. Because of the limitations of radiography and complicacy of the apex of the root, electronic measurement of canal length has become valuable for endodontic treatment. This study was designed to evaluation of the accuracy of the Root zx electronic apex locator in the presence of NaOCl 2.5% and chlorhexidine 0.2%.

Material and Methods

Thirty extracted human premolars with complete root formation were enrolled. The actual length (AL) was assessed visually (under stereo microscope) and teeth mounted in the saline model. The electronic length (EL) measurements were recorded in the presence of NaOCl 2.5% and chlorhexidine 0.2% and the differences between the EL and AL were compared.

Results

By accepting the error of 0.5 and 1 mm, the accuracy of Root zx was 76.7% and 96.7% in the presence of chlorhexidine 0.2% and 90% and 100% in the presence of NaOCl 2.5%, respectively. No statistical differences was found between the measured groups (P=0.223).

Conclusions

Our results confirmed that Root zx can accurately determine the apical constriction in presence of both NaOCl 2.5% and chlorhexidine 0.2%.

Key words:Chlorhexidine, Sodium Hypochlorite, Root ZX.

Influence of the Maxillary Sinus on the Accuracy of the Root ZX Apex Locator: An Ex Vivo Study

This study evaluated the accuracy of the Root ZX (J. Morita, Tokyo, Japan) electronic apex locator in determining the working length when palatal maxillary molar roots are in a relationship with the sinus. Seventeen human maxillary molars with vital pulp were scheduled for an extraction and implant placement as part of a periodontal treatment plan. The access cavity was prepared, and a #10 K file (Dentsply Maillefer, Ballaigues, Switzerland) was inserted into the palatal root using the Root ZX apex locator in order to determine the electronic working length (EWL); then, the teeth were extracted. To determine the real working length (RWL), a #10 K file was introduced into the root canal until its tip touched a glass plate. EWL and RWL were compared. Images reconstructed with CBCT (cone beam computerized tomography) revealed that eight palatal roots were related to the maxillary sinus, whereas nine were not. The results showed a significant difference between the EWL and the RWL of the palatal roots related to the sinus (p < 0.001). No significant difference was observed in measurements of roots not in contact with the sinus (p > 0.05). Within the study limitations, the reliability of Root ZX was influenced by the relationship of the roots with the maxillary sinus.

An in vivo comparison of accuracy of two electronic apex locators in determining working length using stainless steel and nickel titanium files

Purpose

A key factor affecting the success of endodontic treatment is correct determination of root canal working length (WL). The purpose of this in vivo study was to compare the accuracy of Propex II and iPex II electronic apex locator (EAL) in determining the WL under clinical conditions, to that of radiographic working length (RWL) using stainless steel (SS) and nickel–titanium (NiTi) hand files.

Patients and methods

Thirty-seven patients, with 60 anterior teeth (60 canals) scheduled for endodontic treatment participated in this study after ethical approval. Electronic working length (EWL) was determined by the Propex II and iPex II according to manufacturer’s instructions using SS Hand K-files and NiTi Hand files. RWL was determined after EWL determination. The results obtained with each EAL with SS and NiTi files were compared with RWL. Data was analyzed statistically at a significance level of p < 0.05. Interclass correlation coefficient was calculated.

Results

Statistical analysis revealed no significant difference between the EALs, indicating similar accuracies between them with respect to accuracy in determining the WL (p > 0.05). No significant difference was found between the EWL and RWL and between SS and NiTi files for WL determination (p > 0.05) as well. The result also displayed a high intraclass correlation coefficient between the RWL and EWL measurement methods.

Conclusion

Under the in vivo clinical conditions of this study, both Propex II and iPex II were similar to the RWL determination technique showing high correlation to RWL. Both are clinically acceptable EAL for WL determination and both SS hand K-file and NiTi file can be used interchangeably without compromising the WL during treatment.

Accuracy and consistency of electronic root canal length determination with electrically isolating rubber stoppers

The aim of this study was to investigate the influence of an isolating silicone stopper on the measuring accuracy and display consistency of three electrometric apex locators. The length of the canal to the major foramen was determined electrometrically using an ISO size 10 file in 20 extracted teeth each with natural crowns (Group I), amalgam fillings (Group II) or base-metal crowns (Group III), The measurements were performed with isolating or conventional silicone stoppers using three different apex locators with a four-level scale consistency rating. The use of isolating stoppers resulted in a more consistent display than with conventional stoppers, independent of the presence or type of coronal restoration (P = 0.017). Across all coronal restorations, the position of the major foramen could be determined to within ± 0.5 mm without significant differences (P = 0.79) using conventional and isolating stoppers. The use of modified isolating stoppers provides a significant increase in display consistency.

A comparative evaluation of accuracy of three electronic apex locators using histological section as gold standard: An ex vivo study

Introduction:

The aim of the present study was to comparatively evaluate the accuracy of iRoot, iPex II, and Propex pixi apex locator using histological sections as the gold standard.

Materials and Methods:

Thirty patients indicated for extraction of single-rooted permanent teeth with single canal system were selected. Working lengths (WLs) of teeth were determined using iRoot, iPex II, and Propex pixi. Teeth were then extracted, and the files were reintroduced to the anatomic apex to measure anatomic canal length (ACL) and fixed at the ACL using flowable composite. The apical 4 mm of the roots were longitudinally shaved away to visualize the canal under a stereomicroscope at ×24 magnification. Digital photographs were evaluated to measure the distance between the major diameter and minor diameter. Thus, the WL, that is, the minor diameter length (MDL) was ascertained.

Results:

Measurements of mean WLs within ±0.5 mm of minor diameter were 90% acceptable for iRoot, 86.66% for iPex II, and 80% for Propex pixi when compared with mean MDL as obtained from the histological sections.

Conclusions:

All apex locators have been shown to produce acceptable level of accuracy which clearly indicates their reliability in determining the WL.

A comparative assessment of the accuracies of Raypex 5, Raypex 6, iPex and iPex II electronic apex locators: An in vitro study

PURPOSE

The aims of this study were to examine the accuracy of iPex II and to compare it with those of Raypex 5, Raypex 6 and iPex electronic apex locators (EALs).

MATERIALS AND METHODS

Thirty fresh human mandibular premolar teeth were used in this study. Crown segments were cut and root canals were coronally flared. A #10 K-file was inserted until its tip can be seen within apical foramen to determine actual working length (AWL). Teeth were embedded in alginate and each multi-frequency EALs were randomly tested to determine the electronic working length (EWL). Differences between AWLs and EWLs were statistically compared.

RESULTS

No significant differences were found between four EALs. EWL measurements by Raypex 5 were accurate in 64.29%, Raypex 6 in 53.58%, iPex in 64.29% and iPex II in 50% of the specimens, within the range of ±0.5 mm from the AWL.

CONCLUSION

Within the limitations of this in vitro experiment, our findings indicate that the accuracy of working length measurements calculated with iPex II was similar to those of other multi-frequency EALs used in this study.

Comparison of four electronic root canal length measurement devices

OBJECTIVE

The objective of this study is to evaluate the performance of four electronic root canal length measurement devices (ERCLMDs) [Root ZX, Raypex 6, ProPex II, and VDW Gold with ERCLMD] in wet and dry root canals with different major foramen diameters, in association with three file positions within the final 1 mm of canals.

MATERIALS AND METHODS

Fifty roots were divided into five groups that were instrumented apically to the terminus diameter using K-files 15, 20, 30, 40, and 60. ERCLMD measurements were made when the file tip was at major foramen, 0.5 mm and 1.0 mm short of the foramen, when the apex touched to the surface of saline or was immersed 3 mm into saline, and when the canal was dry or was irrigated with saline. The differences between the electronic lengths and the actual lengths were calculated. The data were analyzed using the three-, two-, and one-way ANOVA and the LSD test (p < .05).

RESULTS

Overall, the four ERCLMDs demonstrated 12.8% unstable and beyond the foramen measurements (11.3%). About 85% of the beyond the foramen measurements had foramen diameters 0.40 and 0.60. ERCLMD comparisons related to the file positions in the foramen diameters showed significant differences between ERCLMDs in each foramen diameter (p < .05).

CONCLUSIONS

All ERCLMDs provided highly accurate measurements within the final 1 mm of the foramen. Wet or dry canals and apex conditions did not adversely affect the accuracy of the ERCLMDs' readings. ProPex II located the file positions in the teeth with different foramen diameters more accurately than the other ERCLMDs.

In vivo assessment of accuracy of Propex II, Root ZX II, and radiographic measurements for location of the major foramen

Objectives

The aim of this in vivo study was to assess the accuracy of 2 third-generation electronic apex locators (EALs), Propex II (Dentsply Maillefer) and Root ZX II (J. Morita), and radiographic technique for locating the major foramen (MF).

Materials and Methods

Thirty-two premolars with single canals that required extraction were included. Following anesthesia, access, and initial canal preparation with size 10 and 15 K-flex files and SX and S1 rotary ProTaper files, the canals were irrigated with 2.5% sodium hypochlorite. The length of the root canal was verified 3 times for each tooth using the 2 apex locators and once using the radiographic technique. Teeth were extracted and the actual WL was determined using size 15 K-files under a × 25 magnification. The Biostat 4.0 program (AnalystSoft Inc.) was used for comparing the direct measurements with those obtained using radiographic technique and the apex locators. Pearson's correlation analysis and analysis of variance (ANOVA) were used for statistical analyses.

Results

The measurements obtained using the visual method exhibited the strongest correlation with Root ZX II (r = 0.94), followed by Propex II (r = 0.90) and Ingle's technique (r = 0.81; p < 0.001). Descriptive statistics using ANOVA (Tukey's post hoc test) revealed significant differences between the radiographic measurements and both EALs measurements (p < 0.05).

Conclusions

Both EALs presented similar accuracy that was higher than that of the radiographic measurements obtained with Ingle's technique. Our results suggest that the use of these EALs for MF location is more accurate than the use of radiographic measurements.

Evaluation of Conventional Radiography and an Electronic Apex Locator in Determining the Working Length in C-shaped Canals

Introduction:

The purpose of this in vitro study was to compare the accuracy of working length determination using the apex locator versus conventional radiography in C-shaped canals.

Methods and Materials:

After confirming the actual C-shaped anatomy using cone-beam computed tomography (CBCT), 22 extracted C-shaped mandibular second molars were selected and decoronated at the cemento-enamel junction. The actual working length of these canals were determined by inserting a #15 K-file until the tip could be seen through the apical foramen and the working length was established by subtracting 0.5 mm from this length. The working length was also determined using conventional analog radiography and electronic apex locator (EAL) that were both compared with the actual working length. The data was statistically analyzed using paired t-test and marginal homogeneity test.

Results:

There was no significant differences between the working length obtained with apex locator and that achieved through conventional radiography in terms of measuring the mesiolingual and distal canals (P>0.05); while, significant differences were observed in measurements of the mesiobuccal canals (P=0.036). Within ±0.5 mm of tolerance margin there was no significant difference between EAL and conventional radiography.

Conclusion:

The apex locator was more accurate in determination of the working length of C-shaped canals compared with the conventional radiography.

Influence of instrument size and varying electrical resistance of root canal instruments on accuracy of three electronic root canal length measurement devices

AIM

To evaluate the influence of instrument size and the effect of the electrical resistance of endodontic instruments on the accuracy of three electronic root canal length measurement devices (ERCLMDs).

METHODOLOGY

Thirty single-rooted extracted human teeth were divided into three groups (n = 10) on the basis of the ERCLMD used: Root ZX II (J. Morita, Kyoto, Japan); ProPex (Dentsply Maillefer, Ballaigues, Switzerland); and iPex II (NSK, Tochigi, Japan). The electronic working length measurements (EWL) were made with K-files in the sequence sizes 08, 10, 15, 20, 25 and 30. The actual working length (AWL) was calculated by fixing a size 30 K-file in the canal and exposing the apical 5 mm of the root. The minor foramen was identified under an optical microscope, and its distance from the file tip was calculated. The accuracy of the ERCLMDs was evaluated in terms of percentages of accurate measurements (0.0 mm tolerance) and measurements with tolerance limits of ±0.5 mm and ±1.0 mm. The findings were analysed with the McNemar test, Pearson's chi-square tests and two-way analysis of variance. The multiple comparison procedures were carried out using Holm-Sidak method. The maximum electrical resistance tolerated by ERCLMDs was evaluated by connecting commercially available resistors between the file clip and the root canal instrument. The resistance was gradually increased until it started to affect the ERCLMD readings.

RESULTS

The ERCLMDs were able to actually locate the minor foramen in 7% of samples. File size did not affect the accuracy of ERCLMDs (P > 0.05). Overall, the ERCLMDs gave 65% readings within a tolerance limit of ±0.5 mm and 90% within a tolerance of ±1.0 mm. The electrical resistance of endodontic files was less than the maximum electrical resistance tolerated by ERCLMDs (0.6-1 Ω vs. 2500-4000 Ω).

CONCLUSIONS

The size of the root canal instrument did not affect the accuracy of ERCLMDs in this laboratory study.

An in vitro evaluation of the accuracy of four electronic apex locators using stainless-steel and nickel-titanium hand files

Objectives

The purpose of this in vitro study was to evaluate the accuracy of working length (WL) determination of four electronic apex locators (EALs), namely, Root ZX (RZX), Elements diagnostic unit and apex locator (ELE), SybronEndo Mini Apex locator (MINI) and Propex pixi (PIXI) using Stainless steel (SS) and nickel-titanium (NiTi) hand files. The null hypothesis was that there was no difference between canal length determination by SS and NiTi files of 4 EALs.

Materials and Methods

Sixty extracted, single rooted human teeth were decoronated and the canal orifice flared. The actual length (AL) was assessed visually, and the teeth were embedded in an alginate model. The electronic length (EL) measurements were recorded with all four EALs using SS and NiTi files at '0.5' reading on display. The differences between the AL and EL were compared.

Results

The results obtained with each EAL with SS and NiTi files were compared with AL. A paired sample t test showed that there was a statistical significant difference between EAL readings with SS and NiTi files for RZX and MINI (p < 0.05). The accuracy of RZX, ELE, MINI and PIXI within ± 0.5 mm of AL with SS/NiTi files were 93.3%/70%, 90%/91.7%, 95%/68.3%, and 83.3%/83.3%, respectively.

Conclusions

The results of this study indicate that Root ZX was statistically more accurate with NiTi files compared to SS files, while MINI was statistically more accurate with SS files compared to NiTi files. ELE and PIXI were not affected by the alloy type of the file used to determine WL.

In Vitro Comparison of Raypex 6 and Endopilot Using a Novel, Computer-Aided Measurement System, for Determining the Working Length

Introduction

Experimental evaluation of endometric devices usually relies on visual, subjective detection of the apical constriction to determine the accuracy of measurements. The aim of the present study was to analyze the accuracy of measurements of Raypex 6 and EndoPilot using a novel, objective image-analysis system.

Methods

Onehundred and twenty teeth were randomized and allocated to three groups: After coronal flaring, either Raypex 6 or EndoPilot were used to determine the endodontic working length during instrumentation using manual files (RPM and EPM group respectively). In addition, EndoPilot was used for continuous, automatic measurement during rotating instrumentation (EPA group). If the working length had been reached according to endometric results, the files were fixed in place. Tooth and file were then embedded and prepared for analysis. Subsequently, the distance between the tip of the file and the apical constriction (D_AC) or the apical foramen (D_AF) was calculated using trigonometric analysis and the position of the file relative to AC and AF was analyzed.

Results

Both inter- and intra-examiner-reliability of the trigonometric analysis were nearly perfect (ICC = 0.999, p<0.001). D_AC was not significantly different between groups (p>0.05, t-test). D_AF was significantly decreased when EPA had been used compared to EPM (p<0.05, Exact-test). EPA resulted in files being positioned beyond AF significantly more often than the other two methods (p<0.01).

Conclusions

All methods allowed reliable detection of AC. However, EPA significantly increased the risk of overpreparation. Objective, digital assessment based on image analysis was suitable to compare the accuracy of different endometric devices.

Influence of root canal curvature on the accuracy of an electronic apex locator: An in vitro study

OBJECTIVE

This study investigated whether the canal curvature has an influence on the accuracy of Electronic Apex Locator.

MATERIALS AND METHODS

Sixty mandibular posterior teeth were decoronated. A number (No.) 10 file was inserted into the mesiobuccal canal and radiographs were taken to determine the degree of curvature by Schneider's method. Samples were divided into three groups of mild (<20°), moderate (20-36°) and severe curvature (>36°). After enlarging the orifice, the actual canal length was determined by introducing a file until the tip emerged through the major foramen when observed under 20X magnification. The teeth were embedded in an alginate model and the Root ZX was used to determine the electronic length. The data was analyzed by Kruskal-Wallis test followed by Mann-Whitney test.

RESULTS

The difference in measurement of Actual and Electronic working length was statistically significant between group 1 and 2 (P < 0.05) as well as between group 1 and group 3 (P < 0.05) with group 1 showing the lowest difference.

CONCLUSION

Considering ± 0.5 mm as tolerance limit for accuracy, the device was 95% accurate for the mild curvature group and 80% accurate for moderate and severe groups.

Calcium hydroxide dressing residues after different removal techniques affect the accuracy of Root-ZX apex locator

OBJECTIVES

This study compared the ability of several techniques to remove calcium hydroxide (CH) from the root canal and determined the influence of CH residues on the accuracy of the electronic apex locator.

MATERIALS AND METHODS

Root canals of 90 human maxillary lateral incisors with confirmed true working length (TWL) were prepared and filled with CH. The teeth were randomly assigned to one of the experimental groups according to the CH removal technique (n = 14): 0.9% saline; 0.9% saline + master apical file (MAF); 17% ethylenediamine tetraacetic acid (EDTA); 17% EDTA + MAF; 5.25% sodium hypochlorite (NaOCl); 5.25% NaOCl + MAF. Six teeth were used as negative control. After CH removal, the electronic working length was measured using Root-ZX (Morita Corp.) and compared with TWL to evaluate Root-ZX accuracy. All specimens were sectioned longitudinally, and the area of remaining CH (CH) and total canal area were measured using imaging software.

RESULTS

The EDTA + MAF and NaOCl + MAF groups showed better CH removal than other groups (p < 0.05). Root-ZX reliability to prevent overestimated working length to be > 85% within a tolerance of ± 1.0 mm (p < 0.05). There was strong negative correlation between amount of CH residues and EAL accuracy (r = -0.800 for ± 0.5 mm; r = -0.940 for ± 1.0 mm).

CONCLUSIONS

The mechanical instrumentation improves the CH removal of irrigation solutions although none of the techniques removed the dressing completely. Residues of CH medication in root canals affected the accuracy of Root-ZX adversely.

Accuracy of three electronic apex locators in determining the apical foramen in multi-rooted teeth: Randomised clinical and laboratory study

This study aimed to compare the accuracy of three electronic apex locators (EALs), Raypex 5, Apex NRG and ProPex II, in locating the apical foramen (AF) in vivo. Thirty multi-rooted teeth were included in the study. Distances from the file tip to the radiographic apex from the buccal (R1) and mesial (R2) aspect were measured after extraction. The distance from the file tip to the AF (L) was measured microscopically. Raypex 5, Apex NRG and ProPex II were accurate to within ± 0.5 mm in 84.6%, 78.6% and 66.7% of cases, respectively. R1, R2 and L measurements between the EALs were not statistically different (P > 0.05). R1 and L correlated positively (r(2) = 0.817; P < 0.001). There were no significant differences in all measurements between vital and non-vital root canals (P > 0.05). There was no statistically significant difference between the EALs. There was a positive correlation between electronic and radiographic measurements when locating the AF.

Working Length Determination of Root Canal of Young Permanent Tooth: An In vitro Study

BACKGROUND

Determination of correct working length is one of the keys to success in endodontic therapy.

AIM

The aim of this study was to evaluate the diagnostic efficacy of various methods to determine working length of root canal.

MATERIALS AND METHODS

Tactile method was assessed using digital radiography and compared with electronic method using apex locator. A total sample of 30 single rooted young permanent teeth the (mandibular first premolars) with matured apices were selected for the study. Access cavity preparation was carried out. Working length was measured by tactile method using digital radiography and electronic method using apex locator with no 15 K file. Actual working length was established by grinding of cementum and dentine from the root apex and was observed under stereomicroscope. Data was collected and statistical analysis was carried out with the help of SPSS-15.

RESULTS

The results of this study showed that there was a significant difference between tactile method assessed by digital radiography and electronic method using apex locator.

CONCLUSION

Apex locator was found to be more reliable and accurate when compared with the actual length.

In vivo accuracy of two electronic foramen locators based on different operation systems

The aim of this study was to compare in vivo the accuracy of two electronic foramen locators (EFLs) based on different operation systems - Root ZX and Propex II. Ten healthy adult patients needing premolar extractions due to orthodontic reasons participated in the study, providing a sample of 17 noncarious, non-restored, vital teeth (n= 24 canals). After coronal access preparation and cervical preflaring and prior to tooth extraction, the root canal length was measured alternating the two EFLs. All measurements were performed with K-files well fitted to the canal diameter at the level that each EFL indicated the apical foramen in their display (APEX or 0.0). The last K-file were fixed in place with cyanoacrylate, the tooth was extracted, and the apical 4 mm of each root were resected to measure the distance between the file tip and the apical foramen. The mean errors based on the absolute values of discrepancies were 0.30 ± 0.29 mm (Root ZX) and 0.32 ± 0.27 mm (Propex II). Analysis by the Wilcoxon test for paired samples showed no statistically significant differences between the electronic canal measurements performed with the EFLs (p=0.587). The apical foramen was accurately located in 75% (Root ZX) and 66.7% (Propex II) of the cases, considering a ±0.5 mm error margin, with no statistically significant difference by the chi-square test. Despite having different measurement mechanisms, both EFLs were capable of locating the apical foramen with high accuracy in vivo. Under the tested clinical conditions, Root ZX and Propex II displayed similar results.

Ex vivo accuracy of Root ZX II, Root ZX Mini and RomiApex A-15 apex locators in extracted vital pulp teeth

The objective of this study was to compare, ex vivo, the accuracy of three electronic apex locators (EALs), Root ZX II, Root ZX Mini and RomiApex A-15, in detecting the apical foramen (AF). Forty extracted single-Rooted human teeth with vital pulp were used in this study. After access preparation, the Root canal length of each tooth was measured by placing a #10 file until the tip was visible at the AF under a stereomicroscope. The teeth were subsequently embedded in an alginate model. In each Root canal, all three EALs were used to determine the working length, which was defined as the zero reading or equivalent. The distance between the file tip and AF was measured to an accuracy of 0.01 mm. Results were analyzed using analysis of variance and the Chi-squared test. Root ZX II, Root ZX Mini and RomiApex A-15 were accurate within 0.5 mm, 62.5, 56.2, 50% of the time. No significant differences were found between the three EALs (p > 0.05). Considering all EALs, the mean distance from the file tip to AF was 4.49 mm. The accuracy of the three EALs evaluated in this study was not statistically significantly different. The 'Apex' or '0.0' marks of the EALs do not indicate the AF itself, but just a position coronal 0.49 mm to the AF. Using a tolerance of ± 0.5 mm from the actual lengths, the ZX II yielded the most acceptable measurements.

Influence of apical periodontitis on the accuracy of 3 electronic root canal length measurement devices: an in vivo study

INTRODUCTION

The aim of this in vivo study was to evaluate the influence of apical periodontitis (AP) on the accuracy of Dentaport ZX (J Morita, Kyoto, Japan), Raypex 5 (VDW, Munich, Germany), and i-Root (S-Denti, Seoul, Korea) electronic root canal length measurement devices (ERCLMDs).

METHODS

Thirty-two single-rooted teeth scheduled for extraction, consisting of 16 teeth with AP and 16 teeth with normal periapex (NP), were selected. The access cavity was prepared, and the coronal portion of the canal was flared. The electronic working length (EWL) was determined by each ERCLMD according to each manufacturer's instructions. Each tooth was extracted, and the actual working length (AWL) was determined by inserting a size 15 K-file until the tip could be seen at a position tangential to the major foramen and then 0.5 mm was subtracted from the measurement. The distance from the file tip (EWL) to the point 0.5 mm coronal to the major foramen (AWL) was calculated. Data were analyzed using the nonparametric Fisher exact test and the chi-square test. Statistical significance was set at P < .05.

RESULTS

The accuracies of Dentaport ZX, Raypex 5, and i-Root within ± 0.5 mm in the AP group were 93.8%, 81.3%, and 75.0%; they were 93.3%, 86.7%, and 73.3% in the NP group, respectively. There were no significant differences between the accuracy of each device in the 2 groups (P > .05). Considering the 2 groups of AP and NP, there were no statistically significant differences in the accuracy of the ERCLMDs (P > .05).

CONCLUSIONS

The presence of AP did not influence the accuracy of ERCLMDs.

Effect of chloroform, orange solvent and eucalyptol on the accuracy of four electronic apex locators

The aim of this study was to evaluate the effect of three retreatment solutions on the accuracy of four electronic apex locators, the Root ZX mini, the Mini Apex Locator, the Root ZX and the Elements Diagnostic Unit and Apex Locator. Forty extracted single-rooted human teeth were used in this study. The four electronic apex locators were operated according to the manufacturer's instructions to locate the 'apical constriction' in the presence of chloroform, orange solvent or eucalyptol in the canal. The accuracy of each apex locator was not affected by the type of retreatment solution present in the root canal. In addition, the accuracy of the four apex locators was similar in the presence of each of the tested solutions.

Effect of working length measurement by electronic apex locator or digital radiography on postoperative pain: a randomized clinical trial

INTRODUCTION

The aim of this study was to evaluate the effect of working length determination methods, electronic apex locator and digital radiography, on postoperative pain.

METHODS

Two hundred twenty patients with asymptomatic single-rooted vital teeth were randomly assigned to 2 groups according to the method used for working length determination, the radiographic group and the electronic apex locator group. After working length determination, chemomechanical preparation was performed in a crown-down technique with ProTaper instruments. A master cone radiograph was taken. Canals were obturated with gutta-percha and sealer by using a lateral compaction technique. Postoperative pain was assessed after 4, 6, 12, 24, and 48 hours by using a 4-point pain intensity scale. In addition, patients were asked to record the number of days necessary to achieve complete pain resolution.

RESULTS

Postoperative pain during the 4-hour to 48-hour interval studied was not significantly different (P > .05) between groups. The mean times for pain dissipation in the radiographic and electronic apex locator groups were 3.37 ± 2.79 and 3.88 ± 3.34 days, respectively. The difference between groups was not statistically significant (P > .05).

CONCLUSIONS

There is no difference in postoperative pain between working length measurement methods by using an electronic apex locator or digital radiography. The reduced exposure to radiation by using apex locator may be a factor that influences a dentist's decision to choose the electronic apex locator over radiography.

An in vitro stereomicroscopic comparative evaluation of a combination of apex locator and endodontic motor with an integrated endodontic motor

Objective:

To compare the efficacy of an integrated apex locator and an apex locator and endodontic motor assembly in maintaining the working length when operated under autoreverse mode.

Study Design:

Thirty distobuccal roots of intact maxillary first molars were taken and access cavities were prepared. The teeth were divided into Group I: Prepared with TCM Endo V and Group II: Prepared with ProPex and NSK assembly. The instrumentation was ended in ProTaper F3 file, which was cemented in the canal. The roots were sectioned, observed under a stereomicroscope and the distance from instrument tip to the apical foramen was measured.

Results:

Mean difference in the deviation of two groups was 0.075 mm, P = 0.34 (>0.05) which was statistically insignificant when assessed with unpaired t-test.

Conclusion:

The assembly of ProPex-NSK Endo-mate DT and the apex locating endomotor TCM Endo V Nouvag are clinically acceptable.

An in vivo evaluation of different methods of working length determination

OBJECTIVE

The purpose of this in vivo study was to compare the ability of digital tactile, digital radiographic and electronic methods to determine reliability in locating the apical constriction.

MATERIALS AND METHODS

Informed consent was obtained from patients scheduled for orthodontic extraction. The teeth were anesthetized, isolated and accessed. The canals were negotiated, pulp chamber and canals were irrigated and pulp was extirpated. The working length was then evaluated for each canal by digital tactile sensation, an electronic apex locator (The Root ZX) and digital radiography. The readings were then compared with post-extraction working length measurements.

RESULTS

The percentage accuracy indicated that EAL method (Root ZX) shows maximum accuracy, i.e. 99.85% and digital tactile and digital radiographic method (DDR) showed 98.20 and 97.90% accuracy respectively.

CLINICAL SIGNIFICANCE

Hence, it can be concluded that the EAL method (Root ZX) produced most reliable results for determining the accurate working length.

A comparative evaluation of electronic and radiographic determination of root canal length in primary teeth: An in vitro study

Aims:

The purpose of this in vitro study was to compare the root canal length determination by Electronic apex locator (EAL) (Raypex 5) and conventional radiography, and then compare them with the actual measurements obtained by direct visualization.

Settings and Design:

This study was conducted at the Department of Pedodontics and Preventive Dentistry, Government Dental College, Thiruvananthapuram, Kerala, India.

Subjects and Methods:

One hundred single rooted primary teeth extracted due to extensive caries, trauma, serial extraction or unwillingness of the parent to save the teeth were selected. The teeth were numbered and root canal length was determined using the visual, electronic and the radiographic methods. The actual, electronic and the radiographic measurements were recorded.

Statistical Analysis Used:

Data were analyzed using Intraclass correlation test and linear regression analysis.

Results:

The accuracy of EAL and radiographic methods were 92% and 72%, respectively within + 0.5 mm. Both the electronic and conventional radiographic methods showed a high correlation and agreement (ICC intraclass correlation coefficient = 0.99 and 0.98 respectively) with the actual measurements.

Conclusions:

EALs proved to be more accurate in determining the root canal length than the radiographic method.

Effect of pre-flaring and file size on the accuracy of two electronic apex locators

OBJECTIVE

This ex vivo study evaluated the effect of pre-flaring and file size on the accuracy of the Root ZX and Novapex electronic apex locators (EALs).

MATERIAL AND METHODS

The actual working length (WL) was set 1 mm short of the apical foramen in the palatal root canals of 24 extracted maxillary molars. The teeth were embedded in an alginate mold, and two examiners performed the electronic measurements using #10, #15, and #20 K-files. The files were inserted into the root canals until the "0.0" or "APEX" signals were observed on the LED or display screens for the Novapex and Root ZX, respectively, retracting to the 1.0 mark. The measurements were repeated after the preflaring using the S1 and SX Pro-Taper instruments. Two measurements were performed for each condition and the means were used. Intra-class correlation coefficients (ICCs) were calculated to verify the intra- and inter-examiner agreement. The mean differences between the WL and electronic length values were analyzed by the three-way ANOVA test (p<0.05).

RESULTS

ICCs were high (>0.8) and the results demonstrated a similar accuracy for both EALs (p>0.05). Statistically significant accurate measurements were verified in the pre-flared canals, except for the Novapex using a #20 K-file.

CONCLUSIONS

The tested EALs showed acceptable accuracy, whereas the pre-flaring procedure revealed a more significant effect than the used file size.