In vivo comparison of working length determination with two electronic apex locators

In Vivo and In Vitro Accuracy and Precision Evaluations of Mini Electronic Apex Locators

This study was aimed to evaluate in vivo and in vitro accuracy and precision of Root ZXMini, Raypex6 and PropexPixi electronic apex locators (EALs) in both dry and wet conditions (5.25% NaOCl, sterile saline, 2% chlorhexidine, 17% EDTA). Fifty vital maxillary and mandibular incisors were included in in vivo, and 50 maxillary central incisors were used in the in vitro study. Measurements were classified as successful if stable electronic working lengths (EWLs) were within ±0.5 mm of actual working length (AWL). Statistics were performed using paired sample t-test, Kruskal-Wallis test and Chi-Square (p < 0.05). No significant differences in precision, accuracy and success rates were found among EALs (p > 0.05). Root ZXMini and Raypex6 could directly detect a 0.5 mm coronal zone than major apical foramen (MAF) in both settings. After a 0.5 mm reduction as recommended by the manufacturer, Propex Pixi in vivo EWLs could be between AWL and MAF; in vitro EWLs could be within 0.5 mm coronal than AWL.

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.

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.

In vivo Study to Evaluate the Effect of Instrument Size on the Accuracy of Three Different Apex Locators when Various Irrigation Solutions are used in Vital and Non-Vital Teeth

Introduction

Root canal success requires working length (WL) optimization. The current study examined how different apex locators on vital and non-vital teeth responded to instrument size.

Materials and Methods

Three hundred patients (180 men and 120 women) receiving root canal therapy at the department of Conservative Dentistry and Endodontics were evaluated. Therefore, we determined that 200 of the patients' teeth (100 vital and 100 non-vital teeth from the upper and lower jaws' first molars) qualified for inclusion in our study. The pulp chamber was accessed using a sterile round bur. The coronal region of the root canal was preflared with successive Gates Glidden drills (Mani Inc. Japan) and irrigated with any one of the solutions 3% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), or 17% ethylenediaminetetraacetic acid (EDTA) solution after checking canal patency with a size #10 K file, where (#-number). Later, the working length was established using Ingle's technique and a radiovisiograph (RVG) 0.5 mm short of the radiographic apex. Two endodontists approved this RVG.

Results

Overall, the #15 K file and apex locators did not differ from Ingle's method. While the #8 K file differs significantly from all apex locators, the #10 K file showed a significant difference with all apex locators except Root ZX with 2% CHX (P = 0.06). Irrigation didn't influence apex locators' accuracy.

Conclusion

Even in the presence of irrigating solutions, electronic apex locator (EAL) can be utilized to calculate the working length with accuracy. The apex locators #15 k files, #10 k files, and #8 k files showed the most promising results.

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.

Clinical accuracy and precision of 3 multi-frequency electronic apex locators assessed through micro-CT imaging

INTRODUCTION

This study aimed to compare the in vivo accuracy and precision of 3 electronic apex locators (EALs) in determining the position of the major foramen using micro-computed tomographic (micro-CT) technology.

METHODS

After access preparation of 23 necrotic or vital teeth from 5 patients, canals were negotiated and hand files were used to determine the position of the foramen with 3 EALs: Propex Pixi, Woodpex III and Root ZX II. After fixing the silicon stop to the file, teeth were extracted and scanned in a micro-CT device with and without the instrument inserted into the canal. Datasets were co-registered, and the accuracy and precision of the EALs were determined at a tolerance level of ± 0.5 mm by measuring the distance from the tip of the instruments to a tangential line crossing the margins of the foramen. Statistical comparisons were performed using Friedman with post hoc Related Samples Sign and Spearman tests (α = 5%).

RESULTS

A significant difference was detected comparing the accuracy of Root ZX II (100%), Woodpex III (86.96%) and Propex Pixi (52.17%) (P < .05). There was a lack of significance in the relationship between the pulp status and the accuracy of tested EALs (P > .05). Propex Pixi was significantly less precise than Root ZX II (P < .05), while no difference was found between Woodpex III to either Root ZX II or Propex Pixi (P > .05).

CONCLUSIONS

EALs presented similar precision, but Woodpex III and Root ZX II showed better accuracy to determine the position of the apical foramen than Propex Pixi.

Accuracy of Three Types of Apex Locators versus Digital Periapical Radiography for Working Length Determination in Maxillary Premolars: An In Vitro Study

This study aimed to compare the accuracy of three types of apex locators versus digital radiography for working length (WL) determination. This experimental study was conducted on 58 extracted maxillary premolars. The teeth were decoronated, the access cavity was prepared, and WL was determined using a #15 K-file to serve as reference. The WL was then measured by Woodpex V, Woodpex III, and Root ZX apex locators in the presence of 0.9% saline, and also on a photostimulable phosphor plate (PSP) digital radiograph taken by the parallel technique. The values were compared with the actual WL using the paired t-test (alpha = 0.05). Digital radiography, Root ZX, Woodpex V, and Woodpex III determined the WL within ±0.5 mm from the actual value in 84.48%, 100%, 89.66%, and 87.93% of the cases, respectively. Woodpex V (p = 0.039), Woodpex III (p = 0.001), and Root ZX (p = 0.001) significantly over-estimated the WL. The WL measured on digital radiographs was not significantly different from the actual WL (p = 0.213). The position of the apical foramen (central/lateral) had no significant effect on the accuracy of WL determination by different techniques (p >0.05). Within the limitations of this in vitro study, all the tested modalities showed acceptable accuracy for WL determination in maxillary premolars.

Micro-CT study of the in vivo accuracy of a wireless electronic apex locator

INTRODUCTION

This study aimed to compare the in vivo accuracy of Wirele-X and RootZX II electronic apex locators (EALs) in determining the position of the major foramen using micro-CT as analytical tool.

METHODS

Eleven vital teeth from 5 patients planned for extraction were used. After conventional access cavity preparation, root canals were flared and negotiated up to the apical third with sizes 08 and 10 K-files followed by irrigation with 2.5% NaOCl. K-type files were used to determine the working length of the selected canals using Root ZX II and Wirele-X apex locators until their numeric displays read '0.0'. After fixing the silicon stop to the file, teeth were extracted and imaged in a micro-CT device using a double-scan protocol. Image stacks, with and without the file in the root canal, were then co-registered and the measurement error calculated as the absolute difference between the tip of the file and the major foramen. Positive and negative values were recorded when the file tip was detected beyond or short the major foramen, respectively. Accuracy was determined on stable measurements within ± 0.5 mm when the file tip did not extend beyond the major foramen. The Chi-square test was applied to compare the ability of the EALs to detect the position of the major foramen, while T test for dependent variables was used to verify differences in the two measurements obtained in each tooth. Significance level was set at 5%.

RESULTS

Within a tolerance level of ± 0.5 mm, no significant differences were observed between the tested EALs regarding the absolute distance values (p=0.82) or in their ability to detect the position of the major foramen (Χ²=0.2588; p=0.6109). The accuracy of the Root ZX II and the Wirele-X apex locators within ± 0.5 mm were 81.8% and 90.9%, respectively.

CONCLUSIONS

Root ZX II and Wirele-X performed similarly regarding the in vivo detection of the major foramen. Using strict criteria, the accuracy of the Root ZX II and the Wirele-X apex locators were 81.8% and 90.9%, respectively.

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.

Is canal overinstrumentation able to produce apical root dentinal microcracks in extracted teeth?

AIM

To assess the impact of mechanical overinstrumentation of root canals in extracted teeth on the development of dentinal microcracks in the apical portion of the root by means of micro-computed tomographic (micro-CT) analysis. Root canal preparation short of the canal terminus and at the apical foramen (AF) were used as controls.

METHODOLOGY

Twenty 2-rooted maxillary premolars with two canals were selected, scanned in a micro-CT device and the root canals prepared sequentially using Reciproc M-Wire R25 instruments to working lengths: 1 mm short of the AF (AF - 1 mm), at the AF (AF), and overinstrumentation (AF + 1 mm). A micro-CT scan of each specimen was performed after each time point. After reconstruction and co-registration procedures, the images were screened from the cementoenamel junction to the apex (n = 55 352) to identify the presence of dentinal microcracks in the apical third of the root.

RESULTS

After the analyses of 55 352 slices, dentinal microcracks were visualized in 12.45% of the images (6892 slices), with 5.73% (3174 slices) in the cervical, 3.57% (1976 slices) in the middle and 3.15% (1740 slices) in the apical third. All dentinal microcracks observed at all time points (AF - 1 mm, AF and AF + 1 mm) were already present in the corresponding images before canal instrumentation. Therefore, no new microcracks were detected, regardless of the working length used for canal instrumentation.

CONCLUSION

Reciprocating root canal preparation either short, at or beyond the AF (overinstrumentation) did not create dentinal microcracks in the roots of extracted 2-rooted maxillary premolars.

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.

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.

In Vivo Evaluation of 3 Electronic Apex Locators: Root ZX Mini, Apex ID, and Propex Pixi

INTRODUCTION

The aim of this in vivo study was to compare the accuracy of 3 electronic apex locators (EALs) (Root ZX mini [J Morita Corp, Tokyo, Japan], Apex ID [SybronEndo, Glendora, CA], and Propex Pixi [Dentsply Maillefer, Ballaigues, Switzerland]) to determine the working length.

METHODS

Thirty single-rooted human teeth that were scheduled for extraction were selected for the study. Electronic measurements were performed with the 3 EALs. After the teeth had been extracted, a #10 K-file was used to determine the actual working length, which was established at 0.5 mm short of the major foramen. The data were statistically analyzed with analysis of variance (α = 0.05).

RESULTS

No significant differences were found among the experimental groups (P > .05). The mean distance from the actual working length to the file tip was 0.163 ± 0.032 mm when Root ZX mini was used, 0.343 ± 0.032 mm for Propex Pixi , and 0.012 ± 0.008 mm for Apex ID.

CONCLUSIONS

Under the in vivo conditions of this study, no statistically significant differences were observed among the 3 EALs.

Analysis of Electronic Apex Locators in Human Teeth Diagnosed With Apical Periodontitis

Electronic apex locators (EAL) have been used to establish the working length (WL) in root canal treatment. In teeth diagnosed with apical periodontitis, resorption of tooth apical structures can lead to difficulties to obtain an appropriate WL. The aim was to compare the capacity of three EAL's (Root ZX II, Raypex 6 and Endo-Eze Quill) to locate the tip of the K-file between 0 to -0.5 mm from the apical foramen (AF) on teeth diagnosed with asymptomatic apical periodontitis (AAP). Electronic working length was performed on 60 roots with AAP. A K-file #15 was inserted in the root canal until the apical foramen (AF) was located, and followed was re-adjusted to -0.5 mm through observation in EAL display. The K-file was fixed to the tooth with composite and teeth were extracted. The 4 apical millimeters were worn out until the K-file could be seen and were prepared and measured its distance to AF in a scanning electron microscope. Appropriate WL was when the tip of the K-file was located between 0 to -0.5 mm from AF. Results: Root ZX II showed significant difference (p<0.01) with the other two EALs. Root ZX II presented the better performance than Raypex 6 or Endo-Eze Quill in teeth with AAP.

Comparison of three different apex locators in determining the working length of mandibular first molar teeth with irreversible pulpitis compared with an intraoral periapical radiograph: A block randomized, controlled, clinical trial

AIM

The aim of the present study was to assess the clinical accuracy APEX and 0.5 marks of three different apex locators - iPex II, Root ZX, and Apex ID - before and after canal preparation in the mandibular first molar.

METHODS

Sixty patients between the ages of 13-60 years participated in the study. After access gaining and canal preparation stages files were inserted with the apex locator clip attached until the electronic apex locators (EALs) shows readings of APEX and 0.5 marks and same is confirmed with periapical radiographs. Eighteen apex locator readings were recorded from each tooth, and 1080 readings were obtained from the 60 patients.

RESULTS

Differences among readings from apex locators and radiographic readings were assessed using paired t test. Only in two patients (1 male and 1 female) were the APEX mark readings different from the radiograph estimation. When the 0.5 mark readings of three different EALs were compared with each other, we could observe that the readings from Root ZX differed significantly (P < 0.05).

CONCLUSIONS

In the present study, we observed the negligible differences in readings between the EAL at the APEX mark readings, coinciding with the radiographic observation. Clinically, we recommend the apical foramen be located with the apex locators' APEX mark readings prior to identifying the apical constriction position.

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.

Accuracy of Software-Based Three-Dimensional Root Canal Length Measurements Using Cone-Beam Computed Tomography

Objective

This study aims to evaluate the accuracy of three-dimensional root canal length measurements performed by dentists with different experience levels using a special software based on cone beam com-puted tomography (CBCT).

Methods

A CBCT scan of an artificial resin maxillary molar was used to train dentists (n=65) in using the software (3D Endo, DentsplySirona, Ballaigues, Switzerland) as part of a continuing education course. At the beginning, each participant completed a questionnaire on endodontic and CBCT experiences. After com-prehensive instructions, each participant performed an entire three-dimensional treatment plan by tracing the root canal anatomy between the apical foramen and the center of the canal orifice and simulating a straight-line access. The final root canal length was indicated after the virtual rubber stop of a simulated instrument was adapted to the adjoining cusp. To evaluate the individual accuracy in terms of trueness and precision, differences between the three-dimensional planning and the actual root canal length (ARCL) were calculated, and statistically analyzed.

Results

Mean absolute differences between the measurements with the 3D Endo™ software (n=260) and the ARCL were 0.30±0.22 mm. All measurements were within a limit of ±1 mm. The accuracy of root canal length measurements was significantly influenced by the type of root canal (p<0.0001). The smallest devia-tions were observed for the palatal root canal (0.18±0.13 mm), followed by the mesiobuccal (0.26±0.22 mm), the distobuccal (0.32±0.17 mm), and the second mesiobuccal root canal (0.46±0.24 mm).

Conclusion

Within the limitations of this study, the 3D Endo software enables reproducible and accurate root canal length measurements as part of a three-dimensional endodontic treatment plan. However, mea-surements should always be clinically verified, as root canal morphology has a statistically significant influence.

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.

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.

A comparative clinical evaluation of accuracy of six apex locators with intraoral periapical radiograph in multirooted teeth: An in vivo study

AIM

The purpose of this clinical study was to compare and clinically, to evaluate the accuracy of six apex locators with intra oral periapical (IOPA) radiograph in multirooted teeth.

MATERIALS AND METHODS

A total of 90 multirooted teeth (maxillary and mandibular molars) with irreversible, infected or necrotic pulp tissue and completely formed roots were included in this study and were divided randomly into six groups (Root ZX II, Raypex 6, I-Root, Romiapex A-15, Sybron Endo Mini and Root ZX mini). The working length was determined using six different apex locators, and the accuracy of the apex locators was compared with IOPA radiographs, to be categorized as accurate, short, and long or beyond.

RESULTS

A total of 270 canals were evaluated, of which 233 (86.3%) canals exhibited acceptable working length, 28 (10.4%) canals exhibited short working length, and only 9 (3.3%) canals exhibited working length beyond the apex. There were a statistically significant results in all the groups (P < 0.05) and the comparison between the groups was statistically insignificant.

CONCLUSION

The repeatability with that of apex locators is of great advantage, but the information gained from the radiographs cannot be obtained by any other means. Therefore, it is recommended that radiograph and apex locators are the best combinations in accurately determining the working length and the successful endodontics.

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.

Comparison of third generation versus fourth generation electronic apex locators in detecting apical constriction: An in vivo study

AIM

The aim of this in vivo study was to compare the accuracy of Root ZX and Raypex 5 in detecting minor diameter in human permanent single-rooted teeth.

MATERIALS AND METHODS

Thirty-one patients with completely formed single-rooted permanent teeth indicated for extraction were selected for the study. Crown was flattened for stable reference point and access cavity prepared. Working length was determined with both apex locators. A 15 K file adjusted to that reading was placed in the root canal and stabilized with cement. The tooth was then extracted atraumatically. Following extraction apical 4 mm of root was shaved. The position of the minor diameter in relation to the anatomic apex was recorded for each tooth under stereomicroscope at ×10. The efficiency of two electronic apex locators to determine the minor diameter was statistically analyzed using paired sample t-test.

RESULTS

The minor diameter was located within the limits of ±0.5 mm in 96.6% of the samples with the Root ZX and 93.2% of the samples with Raypex 5. The paired sample t-test showed no significant difference.

CONCLUSION

On analyzing the results of our study it can be concluded that Raypex 5 was as effective as Root ZX in determining the minor diameter.

Comparative evaluation of accuracy of 2 electronic Apex locators with conventional radiography: an ex vivo study

INTRODUCTION

The aim of this ex vivo study was to evaluate the accuracy of the Raypex 5 (VDW, Munich, Germany) and Apex NRG XFR (Medic NRG Ltd, Tel Aviv, Israel) electronic apex locators (EALs) in determining the working length when compared with radiographs.

METHODS

Twenty-five human single-rooted teeth were selected, and the access cavity was prepared. The working length (WL) was determined radiographically and electronically by using 2 EALs. The files were fixed at the WL, and the teeth were extracted. The apical 4 mm of each canal was trimmed to expose the file tip, and the samples were observed under a stereomicroscope. The distance from the file tip to the point 0.5 mm coronal to the anatomic apex was measured. The data were analyzed by using 1-way analysis of variance and the Tukey Honestly Significant Difference test.

RESULTS

There was no significant difference between the Raypex 5 and the Apex NRG XFR devices with respect to their accuracy in determining the final WL. When compared with radiography, both the EALs had no significant difference. When comparing EALs and radiographic measurements with control measurements, accuracy results were found to be 20%, 36%, and 52% for the Raypex 5, Apex NRG XFR, and radiography, respectively. Overestimations of WL determination by the Raypex 5, Apex NRG XFR, and radiography were 4%, 0%, and 40%, respectively. Underestimations of WL determination by the Raypex 5, Apex NRG XFR, and radiography were 76%, 64%, and 8%, respectively.

CONCLUSIONS

Both the EALs had the same accuracy in determining the WL when compared with radiography.

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.

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.

An in vivo study of working length determination with a new apex locator

The success of an endodontic treatment relies on a correct working length determination. The canal terminus must be detected accurately and a precise control of the working length during the endodontic treatment must be maintained. The aim of this study was to investigate the working length determination in vivo with the Quill Apex Locator® for apical limit established at 1 mm short from the apical foramen (AF). Patients scheduled to dental extraction due to orthodontic or periodontal reasons were selected for this study, resulting in a sample of 24 root canals. Written informed consent was obtained from each patient before the treatment. After the administration of local anesthesia each tooth had its pulp cavity accessed. Next, the reading corresponding to the AF showed on the device's display was recorded and the file was removed. With the use of a digital caliper, 1 mm was subtracted from that first measurement. The file with the new measurement was introduced into to the root canal again then fixed with light curing flow composite and the tooth was extracted. Next, one of the apical third walls was worn out to visualize the instrument's point and the AF. The distance from the file tip to the AF was measured by scanning electron microscopy. The average of the measurements was 1.089±0.437 mm. The Bicaudal t-test showed no significant difference (p=0.338) between the experimental values and the hypothetical value tested at 1 mm. The present investigation confirmed that the Quill Apex Locator® was able to determine the working length with good reliability for the endodontic treatment, established at 1 mm short from the AF.

Evaluation of Dentaport ZX and Raypex 6 electronic apex locators: an in vivo study

INTRODUCTION

Raypex 6 is an electronic apex locator (EAL) that has not yet been tested in vivo. The purpose of this in vivo study was to compare the accuracy of two EALs: the Dentaport ZX and the Raypex 6.

METHODS

The study involved 36 straight single-rooted teeth. A 10-K file was advanced until the EAL detected the major foramen. The file was fixed in a replaceable pattern of light-cured composite. The apical part of each canal was trimmed to expose the file tip. The distances from the file tips to the major foramen were measured.

RESULTS

Wilcoxon's signed Rank test found no significant differences between the Dentaport ZX and Raypex 6 in terms of their abilities to detect the major foramen (P = .52) The Dentaport ZX was accurate 82.35% of the time to ± 0.5 mm and 97.05% of the time to ± 1 mm, whereas the Raypex 6 was accurate 88.22% of the time to ± 0.5 mm and 100% of the time to ± 1 mm.

CONCLUSIONS

No statistically significant differences were observed between the performance of the Dentaport ZX and Raypex 6 EALs under the in vivo clinical conditions used in this study.

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.

Evaluation of alginate as a substitute for root-surrounding tissues in electronic root canal measurements

Alginate as a substitute for root-surrounding tissue was investigated. The electronic working lengths of root canals under clinical conditions were compared with an in vitro simulation of the same teeth extracted and embedded in alginate. The working lengths in 26 teeth were determined on two occasions using an electronic apex locator, before extraction and after extraction with the same teeth embedded in an alginate mass. The apical 4 mm of the root canals were exposed following the measurements, and the distances between the apical constrictions and the tips of files repositioned in the canals were measured and recorded. The mean distance between the file tip and the constriction was +0.33 mm (±0.38) in vivo and +0.32 mm (±0.30) in vitro. The Wilcoxon signed-rank test indicated that these means were not significantly different. The apical constriction was assessed to be within the limits of 0.5 mm in 80.7% of in vivo cases and in 76.9% of extracted teeth. Statistical analysis demonstrated that there was no significant difference between the results recorded in vivo and in vitro regarding apical constriction localisation. Based on the results of this study, the alginate mass is a useful tool in evaluating the performance of electronic apex locators.

Accuracy of five electronic foramen locators with different operating systems: an ex vivo study

OBJECTIVE

The aim of this study was to evaluate, ex vivo, the precision of five electronic root canal length measurement devices (ERCLMDs) with different operating systems: the Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApex A-15, and the possible influence of the positioning of the instrument tips short of the apical foramen.

MATERIAL AND METHODS

Forty-two mandibular bicuspids had their real canal lengths (RL) previously determined. Electronic measurements were performed 1.0 mm short of the apical foramen (-1.0), followed by measurements at the apical foramen (0.0). The data resulting from the comparison of the ERCLMD measurements and the RL were evaluated by the Wilcoxon and Friedman tests at a significance level of 5%.

RESULTS

Considering the measurements performed at 0.0 and -1.0, the precision rates for the ERCLMDs were: 73.5% and 47.1% (Root ZX), 73.5% and 55.9% (Mini Apex Locator), 67.6% and 41.1% (Propex II), 61.7% and 44.1% (iPex), and 79.4% and 44.1% (RomiApex A-15), respectively, considering ±0.5 mm of tolerance. Regarding the mean discrepancies, no differences were observed at 0.0; however, in the measurements at -1.0, the iPex, a multi-frequency ERCLMD, had significantly more discrepant readings short of the apical foramen than the other devices, except for the Propex II, which had intermediate results. When the ERCLMDs measurements at -1.0 were compared with those at 0.0, the Propex II, iPex and RomiApex A-15 presented significantly higher discrepancies in their readings.

CONCLUSIONS

Under the conditions of the present study, all the ERCLMDs provided acceptable measurements at the 0.0 position. However, at the -1.0 position, the ERCLMDs had a lower precision, with statistically significant differences for the Propex II, iPex, and RomiApex A-15.

In vivo evaluation of the iPex and Root ZX electronic apex locators using various irrigants

AIM

To evaluate in vivo the performance of the iPex and Root ZX electronic apex locators (EALs) in the presence of several irrigant solutions: 2.5% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX).

METHODOLOGY

Thirty-two single-rooted human teeth that were scheduled for extraction were selected. Teeth with metallic restorations, fractures, root resorption, pulp necrosis or open apices were not included The working length (WL) was determined electronically for the root canals with the iPex and Root ZX EALs in the presence of two different irrigant solutions, 2.5% NaOCl and 2% CHX. After the teeth had been extracted, a size 10 K-file was used to determine the reference working length (RWL), which was established at 0.5 mm short of the major foramen. In each case, the RWL was subtracted from the electronic measurements. Positive values indicated electronic measurements that exceeded the RWL (long measurements), whereas negative values indicated measurements that were short of the RWL. The values obtained with the different irrigants and EALs were compared using the paired t-test. Significance was set at P < 0.05.

RESULTS

The accuracy of the iPex nor Root ZX EAL was not affected by 2.5% NaOCl or 2% CHX (P > 0.05). However, significant differences were observed between the readings of the iPex and Root ZX, irrespective of whether 2.5% NaOCl or 2% CHX was used as the irrigant (P < 0.05). The iPex was less accurate than the Root ZX in determining the RWL.

CONCLUSIONS

The accuracy of neither the iPex nor Root ZX EAL was affected by the irrigant used. However, the iPex was less accurate than the Root ZX in determining the RWL both for 2.5% NaOCl and for 2% CHX.

Comparison of accuracy of two electronic apex locators in the presence of various irrigants: An in vitro study

AIM

This study was designed to compare the accuracy of Root ZX and SybronEndo Mini, electronic apex locators (EALs), in the presence of various irrigants.

MATERIALS AND METHODS

Sixty extracted, single-rooted human teeth were decoronated and the root canals coronally flared. The actual length (AL) was assessed visually and teeth mounted in the gelatin model. The electronic length (EL) measurements were recorded with both EALs in the presence of 0.9% saline; 1% sodium hypochlorite (NaOCl); 2% chlorhexidine digluconate (CHX), and 17% EDTA solution, at "0.5" reading on display. The differences between the EL and AL were compared.

RESULTS

The accuracy of EL measurement of Root ZX and Sybron Mini within±0.5 mm of AL was consistently high in the presence of NaOCl and found to be least with EDTA.

CONCLUSION

EL measurements were shorter with 1% NaOCl, whereas longer with 2% CHX for both the devices. Sybron Mini was more accurate with 1% NaOCl and 2% CHX than Root ZX.

Clinical evaluation of Root ZX II electronic apex locator in primary teeth

AIM

To evaluate the accuracy of Root ZX II electronic apex locator (EAL) for root canal working length determination in primary teeth.

METHODS

Forty primary maxillary incisor teeth were included in the study. Root ZX II EAL was used to determine the electronic working length (EL). The working length obtained with EAL was evaluated using digital radiography with the measuring file set to EL. The samples were categorised into three groups. Group 1 (acceptable): file tip 0-1mm short of the radiographic apex; Group 2 (short): file tip > 1mm short of the apex and Group 3 (long): file tip beyond the apex. Digital radiographic working length (RL) was derived by adjusting EL to the radiographic apex. The assigned calibrations were tabulated and statistically analysed.

RESULTS

Group 1 included 28 out of 40 teeth indicating a clinical accuracy of 70%. Group 2 contained 10 (25%) teeth whereas group 3 had only 2 (5%) teeth.

STATISTICS

Pearson correlation coefficient statistical analysis showed a high correlation (r = +0.82; p<0.001) among the groups.

CONCLUSION

Root ZX II EAL can be used as a reliable device for obtaining root canal length in primary maxillary incisor teeth.

In vivo accuracy of three electronic root canal length measurement devices: Dentaport ZX, Raypex 5 and ProPex II

AIM

To compare in vivo three different electronic root canal length measurement devices: Dentaport ZX, Raypex 5 and ProPex II.

METHODOLOGY

Thirty single-rooted permanent teeth scheduled for extraction because of periodontal disease were selected from 10 adult patients (ranging from 45 to 67 years) and divided into three groups of 10 teeth. Before the extraction, an access cavity was prepared and the crown was adjusted to establish a stable reference point for all measurements. The working length in Group 1 was determined using the Dentaport ZX apex locator. A K-file with the largest diameter that could reach the last green bar on the screen was stabilized in the canal using a dual-curable flow resin composite. The same procedure was used for the Raypex 5 (the file reached the last yellow bar) and Propex II (0.0 orange bar) apex locators. The teeth were then extracted and cleared. The distance between the tip of the file and the major foramen was then calculated for each tooth using digital photography according to Axiovision AC software (Carl Zeiss). Positive values were assigned when the file tip passed beyond the major foramen, negative values when the tip was short of the foramen and zero value when the file tip and the foramen coincided. Statistical analysis was performed using the chi-squared test or Fisher's exact test (P ≤ 0.05).

RESULTS

  Dentaport ZX, Raypex 5 and ProPex ΙΙ produced, respectively, 6, 2 and 4 out of 10 correct measurements, 0, 6 and 5 long measurements and 4, 2, and 1 short measurements. The differences between the three electronic root canal length measurement devices were not significant (P = 0.507).

CONCLUSIONS

Under the in vivo conditions of this study, the three electronic root canal length measurement devices were not significantly different in terms of locating the major foramen.

Clinical reproducibility of three electronic apex locators

AIM

To compare the reproducibility of three electronic apex locators (EALs), Dentaport ZX, RomiApex A-15 and Raypex 5, under clinical conditions.

METHODOLOGY

Forty-eight root canals of incisors, canines and premolars with or without radiographically confirmed periapical lesions required root canal treatment in 42 patients. In each root canal, all three EALs were used to determine the working length (WL) that was defined as the zero reading and indicated by 'Apex', '0.0' or 'red square' markings on the EAL display. A new K-file of the same size was used for each measurement. The file length was fixed with a rubber stop and measured to an accuracy of 0.01 mm. Measurements were undertaken by two calibrated operators. Differences in zero readings between the three EALs in the same root canal were statistically analysed using paired t-tests with the Bonferroni correction, Bland-Altman plot and Linn's concordance correlation coefficients at α = 0.05.

RESULTS

Mean and standard deviation values measured by the three EALs showed no statistically significant differences. Identical readings by all three EALs were found in 10.4% of root canals. Forty-three per cent of readings differed by less than ± 0.5 mm and 31.3% exceeded a difference of ± 1 mm.

CONCLUSIONS

The clinical reproducibility of Dentaport ZX, RomiApex A-15 and Raypex 5 was confirmed with the majority of readings within the ± 1.0 mm range. However, the small number of identical zero readings suggests that EALs are not reliable as the sole means of WL determination under clinical conditions.

An ex vivo comparison of electronic apex locator teaching models

INTRODUCTION

This study aimed to develop a simple and inexpensive ex vivo model to teach students the use of electronic apex locators in a preclinical setting.

METHODS

Using 27 extracted human teeth, the Raypex 5 (VDW, Munich, Germany) and Dentaport ZX (J. Morita Co, Kyoto, Japan) were tested in three different media (ie, alginate, sugar-free gelatin, and 0.9% sodium chloride solution). Working lengths determined by these models were compared with those obtained by digital radiography and direct visualization using a linear mixed modeling statistical approach.

RESULTS

Raypex 5 exhibited a higher percentage of measurements accurate to ± 0.5 mm and ± 1.0 mm of the control across all three media in all tooth types. In multirooted teeth, alginate showed the highest accuracy.

CONCLUSIONS

The most accurate EAL/embedding medium combination was Raypex 5/alginate to both ± 0.5 mm and ± 1.0 mm of the control. The model tested in this study was accurate, easy to assemble, and cost-effective, making it suitable for teaching purposes.