Accuracy of a new apex locator: an in vitro study

A Comparative Ex Vivo Study on Apex Locator Precision in Mature Teeth and Immature Teeth With Divergent Canals

AIM

This study investigates the accuracy of an apex locator in mature and immature teeth with divergent root canals ex vivo.

MATERIALS AND METHODS

Fifty extracted premolar teeth were utilized for the study, with 25 mature teeth (Nolla stage 9 or 10) and 25 immature teeth (Nolla stages ≤ 8). The discrepancies between the actual length (AL) and the electronic length (EL), measured using a Bingo 1020 apex locator, were compared and analyzed. Statistical analysis included Pearson's correlation analysis, a T-test for independent samples, and multiple linear regression. Statistical significance was set at p < 0.05.

RESULTS

The difference between AL and EL in immature teeth was significantly higher than in mature premolar teeth. Nonetheless, patient gender or jaw type (upper/lower) did not affect the accuracy of electronic apex locator (EAL) measurements.

CONCLUSION

EAL readings are less accurate in immature teeth than in mature teeth. Supplementary measures, such as radiographic length determination and wet-dry paper point tests, are required to confirm the working length for improved treatment outcomes and patient compliance.

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

Aim

An accurate working length (WL) estimation is fundamental to a successful endodontic therapy. The objective of this comparative in vitro research was to investigate the performance of iPex II and the Root ZX Mini electronic apex locators (EALs) in measuring root canal WL with different irrigant solutions and their relation to the electrical conductivity of irrigation solutions.

Materials and Methods

Seventy sound permanent lower premolar teeth, each with a single root and developed apices, were used. Under an X15 stereomicroscope, the real working length was determined with the aid of a #10 file. After that, teeth were placed into an alginate model, and the iPex II and Root ZX Mini were used for the detection of electronic working length with various irrigants. Seventy teeth were randomly distributed into seven groups, 10 per each group (group I: dry canal; group II: distilled water; group III: ozonated water; group IV: 5% sodium hypochlorite (NaOCl); group V: 2% chlorhexidine, group VI: 17% ethylenediaminetetraacetic acid (EDTA) solution, and group VII: 17% EDTA gel). The difference in WL was calculated by deducting real working length from its electronic working length. The study also evaluates the electrical conductivity of the seven endodontic irrigant solutions. The two-way analysis of variance (ANOVA) test was used for statistical analysis.

Results

Statistically, neither both types of EALs (P = 0.088) nor various irrigating solutions with varying electrical conductivities (P = 0.099) significantly affect the accuracy of EL estimation.

Conclusions

There were no significant differences between the accuracy of the Root ZX Mini and the iPex II. The accuracy of both apex locators is unaffected in the presence of various irrigation solutions with varying electrical conductivities in this research.

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.

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.

Accuracy of electronic apex locators using heat-treated Ni-Ti file

This study investigated the accuracy of two electronic apex locators (DentaPort and Bingo) using heat-treated nickel-titanium files. The true root canal length of 30 single-rooted teeth was determined using K files. Next, the electronically measured length was determined using two nickel-titanium files (ProGlider and HyFlex EDM Glide Path File) with two electronic apex locators at the 'APEX' marks. The accuracy of the electronic apex locator was evaluated by comparing the true root canal length and electronically measured length for each measurement. There was no significant difference between the measurements with two nickel-titanium files, and all differences between true root canal length and electronically measured length were within ±0.5 mm regardless of the type of nickel-titanium files or electronic apex locators. Based on the results, the heat treatment of the nickel-titanium files showed no adverse effects on the working length determination using electronic apex locators.

Comparison of Accuracy of Dentaport ZX, Rootor and E-Pex Pro Electronic Apex Locators in Two Simulated Clinical Conditions: An In Vitro Study

Background:

Materials and Methodology:

Results:

Conclusion:

The effect of different confluence confirmation strategies on the obturation of Vertucci type II canal: micro-CT analysis

Objectives

The present study aims to compare the obturation quality of 2 confluence confirmation techniques in artificial maxillary first premolars showing Vertucci type II root canal configuration.

Materials and Methods

Thirty artificial maxillary premolars having Vertucci type II root canal configuration were made. They were divided into 3 groups according to the confluence confirmation technique as follows. Gutta-percha indentation (GPI) group (confluence confirmation using a gutta-percha cone and a K file); electronic apex locator (EAL) group (confluence confirmation using K files and EAL); and no confluence detection (NCD) group. In the GPI group and the EAL group, shaping and obturation were performed with the modified working length (WL). In the NCD group, shaping was performed without WL adjustment and obturation was carried out with an adjusted master cone. Micro-computed tomography was used before preparation and after obturation to calculate the percentage of gutta-percha occupied volume (%GPv) and the volume increase in the apical 4 mm. Data were analyzed using 1-way analysis of variance and post hoc Tukey's test.

Results

Statistically significant difference was not found in terms of the %GPv from the apex to apical 4 mm. However, the NCD group showed a statistically significant volume increase compared with the EAL group (p < 0.05).

Conclusions

In terms of gutta-percha occupied volume, no significant difference was observed among the 3 groups. Confluence confirmation using an EAL in teeth with Vertucci type II configuration showed less volume increase during canal shaping compared with no confluence confirmation.

A Comparative Evaluation of Efficacy of Electronic Apex Locator, Digital Radiography, and Conventional Radiographic Method for Root Canal Working Length Determination in Primary Teeth: An In Vitro Study

Aim

Pulpectomy in the primary tooth has unique challenges due to morphological variations in root pattern and physiological root resorption. The electronic apex locator (EAL) is one of the recent methods to determine the estimation of working length without much radiation exposure to the patient as well as the operator. The present study was undertaken for evaluating and comparing the efficacy of EAL, conventional radiography, digital radiography, and actual visual method for the estimation of in the root canal working length (RCL) in extracted primary teeth.

Materials and methods

Ninety extracted, single-rooted primary teeth were selected. Working length estimation was done with an EAL, conventional, and digital radiographic method, and compared it with an actual visual method.

Results

Accuracy of EAL was observed to be 99.7% followed by digital radiograph (98.1%) and conventional radiograph (96.1%). Both EAL and digital radiographic methods showed a high correlation as compared to conventional. The comparative efficacy of an EAL with a visual method was found to be statistically non-significant (p > 0.005).

Conclusion

Root canal working length determined through the electronic method was found to be an accurate and effective tool in single-rooted primary teeth and can be indicated for clinical implementation in endodontic treatment of primary teeth.

How to cite this article

Sahni A, Kapoor R, Gandhi K, et al. A Comparative Evaluation of Efficacy of Electronic Apex Locator, Digital Radiography, and Conventional Radiographic Method for Root Canal Working Length Determination in Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(5):523–528.

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.

Comparative Evaluation of Accuracy of Ipex, Root Zx Mini, and Epex Pro Apex Locators in Teeth with Artificially Created Root Perforations in Presence of Various Intracanal Irrigants

Objective:

The study aimed to compare and evaluate the accuracy of iPex, Root ZX mini, and Epex Pro Electronic apex locators (EALs) in diagnosing root perforations in both dry and in different wet conditions: 5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), and 17% Ethylenediaminetetraacetic acid (EDTA).

Methods:

Thirty extracted, human single rooted mandibular premolars were artificially perforated with a diameter of 1.5 mm in middle third of root. Actual canal lengths (ALs) in millimetre (mm) were evaluated for all teeth up to perforation location, and alginate mould were used to embed the teeth. After this, the electronic measurements were calculated by all EALs up to perforation site using a 20 K-file in both dry and wet canal conditions. Up to the perforation sites, the ALs were subtracted from the electronic length. Statistical analyses were done using One-way ANOVA with post hoc tukey’s test for pairwise comparison and the level of significance was set at 0.05.

Results:

All three EAL’s detected canal perforations which were clinically acceptable. There was significant difference for dry and wet conditions. Most accurate measurement were seen in dry canals for all three EALs. Root ZX mini in dry condition showed most accurate reading and there was a significant difference when compared with other groups. No significance difference was observed in iPex and Epex Pro Apex locator, and between NaOCl and CHX, CHX and EDTA.

Conclusion:

Perforations were determined within a clinical acceptable range of 0.03–0.05 mm by all three EALs. Root ZX mini in dry canals gave most accurate measurement. The presence of irrigating solution influenced the accuracy of all the apex locators.

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.

The Precision of Propex Pixi with Different Instruments and Coronal Preflaring Procedures

Objective

This study aimed to evaluate the influence of the instrument regarding the apical fit and type of the alloy and coronal preflaring procedures in the accuracy of Propex Pixi.

Methods

A total of 40 extracted human single-rooted permanent teeth with apical diameters of 200 µm were selected. A #10 K-file was inserted in the root canal until its end could be observed by a dental microscope to obtain the actual working length (WL). Electronic measurements were performed using Propex Pixi to the root apex ("0.0"). Different file alloys (stainless steel [SS] and nickel titanium [NiTi]) and sizes (#10, #15, and #20) were used before and after coronal flaring. Statistical analysis was performed by a factorial analysis of variance (P≤0.05).

Results

Results showed that the measurements of electronic length (EL) were closer to the actual working length (WL) after coronal flaring (P<0.05). A significant intraclass correlation was observed between EL and WL. In addition, results showed no significant differences between files with different sizes or alloys.

Conclusion

Under the conditions of this study, Propex Pixi demonstrated adequate precision. Its accuracy was enhanced by coronal preflaring procedures regardless of the instrument type used (SS or NiTi) and the apical fit.

A comparative evaluation of two working length determination methods

The purpose of this study was to explore the level of agreement between the radiographic and the electronic apex locator (EAL) working length assessment methods, amongst teeth with different diagnoses. Working length measurements along with pulpal and periapical diagnoses data were collected from the Patient Registry Database of our Institution. The null hypothesis of this study was that pulp status does not affect the level of agreement between the two methods. The degree of agreement was assessed using the Bland-Altman method, followed by a Kruskal-Wallis test (a = 5%) that would allow the null hypothesis to be accepted. The EAL measurements agree in general with those provided by a 1.5 mm file placed coronal to the radiographic apex amid teeth with different pulpal diagnoses. Within the limitations of this study, we suggest that this setting (i.e. the distance) may be applied to all cases of endodontically treated teeth, despite the differences in pulpal diagnosis.

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.

The Influence of Various Irrigants on the Accuracy of 2 Electronic Apex Locators in Locating Simulated Root Perforations

INTRODUCTION

The aim of this study was to assess the accuracy of the Dentaport ZX (Morita Co, Kyoto, Japan) and the Rootor (Meta Biomed, Cheongwon-gun, Korea) electronic apex locators (EALs) in detecting root perforations in dry conditions and in the presence of the following irrigation solutions: 2.5% sodium hypochlorite (NaOCl), 0.9% saline solution (NaCl), and 17% EDTA.

METHODS

Twenty extracted, single-rooted human teeth were perforated artificially in the middle section. The actual canal lengths (ALs) up to the perforation site were determined, and then the teeth were embedded in an alginate mold. The electronic measurements of the perforations were obtained using a size 20 K-file by each EAL in various conditions. For each tooth, the AL was subtracted from the electronic length of the perforation. Statistical analyses were performed using the Friedman and Wilcoxon signed rank tests at a significance level of P < .05.

RESULTS

The most accurate measurements for both EALs were obtained in dry conditions. Among the irrigation solutions in the Dentaport ZX group, EDTA gave the most accurate results, and NaOCl gave the least accurate ones. However, measurements with NaCl were closer to the AL than those obtained with EDTA for the Rootor group. Significant differences were noted among the EALs when the measurements were taken with NaOCl, NaCl, and EDTA (P < .05).

CONCLUSIONS

The Dentaport ZX was more accurate compared with the Rootor in the presence of different irrigants. The content of the root canal affected the accuracy of both EALs. The most accurate measurements were obtained in dry canals.

An ex vivo comparison of working length determination by three electronic root canal length measurement devices integrated into endodontic rotary motors

AIM

The objective of this study was to compare the accuracy of working length (WL) determination by X-Smart Dual, ENDOAce, and Gold Reciproc motor, in manual mode and mechanical preparation set to auto apical reverse (AAR) mode.

MATERIALS AND METHODS

Forty-five anterior teeth were included in the study. The canal length was determined by introducing #10 file into the canal until it emerged at the apical foramen. The incisal edges were adjusted to obtain 18 mm standard length. The teeth were embedded in Plexiglas tubes, filled with alginate, and measured in manual and AAR modes.

RESULTS

Within and between the groups, there was no significant difference in WL measurements, both in manual and AAR modes. In the X-Smart Dual group, all manual measurements were within root canal limits, while 13 % of AAR mode measurements were recorded when the file tip passed the apical foramen. In the ENDOAce group, 13 and 7 % of the measurements, in manual and AAR modes respectively, were recorded when the file tip passed the foramen. In the Gold Reciproc motor group, 27 and 33 % of the measurements, in manual and AAR modes respectively, were recorded when the file tip passed the foramen.

CONCLUSION

With the limitation of this ex vivo study, the tested devices presented no significant differences in length measurements and were within the clinical accepted margin of error.

CLINICAL RELEVANCE

Mechanical preparation must be confined to the root canal system. The adverse results of overinstrumentation emphasize the need to reconsider the ±0.50 mm margin of error that is clinically acceptable for WL measurements.

The effect of residual calcium hydroxide on the accuracy of a contemporary electronic apex locator

OBJECTIVE

The aim of this study was to evaluate the effect of residual calcium hydroxide [Ca(OH)2] on the accuracy of an electronic apex locator (EAL).

MATERIALS AND METHODS

Working lengths (WLs) of 56 extracted maxillary incisors were determined initially by two different methods. The first method used the 'APEX' reading of the EAL as a reference point, 0.5 mm was subtracted and recorded as WL0. The second method used the '0.5' reading and the score was recorded as WL0.5 without subtraction. The roots were prepared to WL0 and divided randomly into three experimental groups (n = 16) (1 mm in group A, 2 mm in group B and 4 mm in group C) and a control (n = 8). Specimens in all experimental groups were filled with Ca(OH)2 paste. Following its removal, WLs were re-determined with the same methods.

RESULTS

In group C, pre/post WLs were significantly different (p < 0.05). No significant difference was observed between the other experimental groups and the control group.

CONCLUSION

Accuracy of EAL decreased proportionally with the amount of paste remaining at the ±0.5-mm tolerance level. Ca(OH)2 paste remnants may cause incorrect EAL readings.

Root canal treatment and special needs patients

AIM

To identify current trends of root canal treatment for patients with special needs.

METHODOLOGY

A postal questionnaire was sent to General Dentists in Victoria, Australia and Endodontists and Special Needs Dentists across Australia to determine the extent of root canal treatment performed on special needs patients.

RESULTS

Over a four-month period, 1120 questionnaires were distributed with an overall response rate of 63.9% (n = 716). Response rates were 63.2% (n = 655), 68.5% (n = 50) and 100.0% (n = 11) amongst General Dentists, Endodontists and Special Needs Dentists, respectively. Endodontists (95.7%) and Special Needs Dentists (100.0%) performed significantly more root canal treatment on adult patients with special needs compared with 51.2% of General Dentists, (P < 0.001 and P = 0.001 respectively; Fisher's exact test). The most common reasons for not undertaking root canal treatment included limited cooperation, poor oral hygiene and uncontrolled movement. Amongst General Dentists, 75.7% opted for extraction in preference to root canal treatment. Significantly, more specialist practitioners performed root canal treatment utilizing conscious sedation (P < 0.001) and general anaesthesia (P = 0.003). Most specialist practitioners (69.1%) had undertaken single-visit root canal treatment on special needs patients compared with only 29.7% of General Dentists (P < 0.001).

CONCLUSIONS

Root canal treatment in special needs patients was more likely to be carried out by specialist dental practitioners who were more likely to utilize a pharmacological approach for behaviour guidance and to perform single-visit root canal treatment compared with General Dentists. A multidisciplinary approach for special needs patients who require root canal treatment provides an opportunity for these patients to retain their dentition.

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.

Efficiency of 2 electronic apex locators on working length determination: A clinical study

AIMS

The aim of this clinical study was to evaluate the clinical accuracy of two electronic apex locators (EALs).

MATERIALS AND METHODS

A total of 120 patients with 283 roots were randomized into three groups including, traditional radiographic method, EAL (Root ZX mini), and apex locating endodontic motor (VDW Gold) for working length (WL) determination. Root canals were instrumented to a size ProTaper F3 nickel titanium file. The obturation quality of matched tapered master cone (ProTaper F3) was determined for the accuracy of WL.

STATISTICAL ANALYSIS USED

Descriptive statistics were expressed as numbers and percentages. Pearson Chi-square test was used to determine for differences between groups. P < 0.05 was considered statistically significant for all tests.

RESULTS

There was no statistically significant difference between the three tested groups (P = 0.894).

CONCLUSIONS

The success of both apex locators was similar to the radiographic WL determination technique.

Accuracy of electronic apex locator in enlarged root canals with different root canal irrigants: an in vitro study

AIM

To evaluate the accuracy of Root ZX-II (J Morita Corp) apex locator in enlarged root canals with different root canal irrigants.

MATERIALS AND METHODS

48 freshly extracted single rooted mandibular premolar teeth were used. The apical enlargement was done up to #45 K-file as the master apical file (MAF). The teeth were randomly divided into 4 groups and mounted in an experimental apparatus. The following irrigants were used during electronic canal measurements: group 1: saline; group 2: 3% NaOCl; group 3: 2% chlorhexidine; group 4: 17% EDTA. The canal measurement was done with Root ZX-II apex locator using #10 and #45 K-file. Data were analyzed by two way ANOVA and Bonferroni multiple comparison test.

RESULTS

Statistical analysis showed that there was statistically significant difference between #10 and #45 K-file for group 1 (p < 0.01).

CONCLUSION

Root ZX-II was accurate in the presence of 3% NaOCl and 17% EDTA when measured with smaller and larger files. However, it was accurate in the presence of saline and 2% CHX when larger files were used.

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 solvents on the accuracy of the Mini Root ZX apex locator

AIM

To evaluate ex vivo, the effects of three solvents on the accuracy of a contemporary electronic root canal length measurement device (ERCLMD), the Mini Root ZX.

METHODOLOGY

The actual working length (AWL) of 56 extracted maxillary incisor teeth were measured with an ERCLMD. All root canals were prepared with the ProTaper system to AWL. Of them, 20 were filled with gutta-percha and a resin-based sealer (Group A), 20 with gutta-percha and a zinc oxide/eugenol-based sealer (Group B), and 16 roots were used as the control group (Group C). Removal of the root filling and repreparation processes were performed using the ProTaper system. Guttasolv and Resosolv were used as the solvents in Group A and Guttasolv and Endosolv E in Group B. After the removal of the root fillings had been achieved, the same ERCLMD was used to measure the working length (WL). Differences between AWL and WL measurements were analysed by paired t-test, and the accuracy of ERCLMD was assessed using chi-squared tests.

RESULTS

There were significant differences between AWL and WL measurements in subgroups A2 (Resosolv group) and B2 (Endosolv E group). In these subgroups, WL was shorter than AWL (P < 0.05). Also, the accuracy of the Resosolv group was significantly lower than the others (P < 0.05) at a ±0.5 mm margin of error.

CONCLUSIONS

Removing root fillings may require use of a solvent. In these cases, ERCLMDs may exhibit a lower accuracy, thus operators must exercise additional care when measuring the working length using ERCLMDs.

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.

Effects of Dissolving Solutions on the Accuracy of an Electronic Apex Locator-Integrated Endodontic Handpiece

The effects of three dissolving agents on the accuracy of an electronic apex locator- (EAL-) integrated endodontic handpiece during retreatment procedures were evaluated. The true lengths (TLs) of 56 extracted incisor teeth were determined visually. Twenty teeth were filled with gutta-percha and a resin-based sealer (group A), 20 with gutta-percha and a zinc oxide/eugenol-based sealer (group B), and 16 roots were used as the control group (group C). All roots were prepared to TL. Guttasolv, Resosolv, and Endosolv E were used as the dissolving solutions. Two evaluations of the handpiece were performed: the apical accuracy during the auto reverse function (ARL) and the apex locator function (EL) alone. The ARL function of the handpiece gave acceptable results. There were significant differences between the EL mode measurements and the TL (P < 0.05). In these comparisons, Tri Auto ZX EL mode measurements were significantly shorter than those of the TL.

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

Context:

The establishment of appropriate working length is one of the most critical steps in endodontic therapy. Electronic apex locators have been introduced to determine the working length. The development of electronic apex locators has helped make the assessment of the working length more accurate and predictable, along with reduction in treatment time and radiation dose.

Objectives:

The aim of this study was to compare the efficacy of electronic apex locators after cleansing and shaping of the root canals and whether there was any alteration in accuracy when used in the presence of irrigants.

Materials and Methods:

Seventy extracted human permanent molars with mature apices were selected. Equal number of maxillary and mandibular permanent molars (35 each) were sectioned at the cemento-enamel junction. Access opening was done and only the mesiobuccal root canal was studied for the purpose of standardization. Electronic working length measurements were taken before and after preparation of the mesiobuccal canal with Root ZX and ProPex II using various irrigants.

Statistical Analysis Used:

The data were statistically analyzed using a paired t-test at 0.05 level of significance.

Results:

P-values for actual and final canal lengths for Root ZX employing NaoCl(0.001), CHX(0.006), LA(0.020) and for ProPex II was (0.001) respectively. When the data were compared, results were statistically significant (P < 0.05).

Conclusion:

Within the limitations of this study Root ZX can be considered to be an accurate electronic apex locator and CHX as irrigant matched more precisely with the actual canal length measurements.

Accuracy of Root ZX in teeth with simulated root perforation in the presence of gel or liquid type endodontic irrigant

Objectives

To evaluate the accuracy of the Root ZX in teeth with simulated root perforation in the presence of gel or liquid type endodontic irrigants, such as saline, 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine liquid, 2% chlorhexidine gel, and RC-Prep, and also to determine the electrical conductivities of these endodontic irrigants.

Materials and Methods

A root perforation was simulated on twenty freshly extracted teeth by means of a small perforation made on the proximal surface of the root at 4 mm from the anatomic apex. Root ZX was used to locate root perforation and measure the electronic working lengths. The results obtained were compared with the actual working length (AWL) and the actual location of perforations (AP), allowing tolerances of 0.5 or 1.0 mm. Measurements within these limits were considered as acceptable. Chi-square test or the Fisher's exact test was used to evaluate significance. Electrical conductivities of each irrigant were also measured with an electrical conductivity tester.

Results

The accuracies of the Root ZX in perforated teeth were significantly different between liquid types (saline, NaOCl) and gel types (chlorhexidine gel, RC-Prep). The accuracies of electronic working lengths in perforated teeth were higher in gel types than in liquid types. The accuracy in locating root perforation was higher in liquid types than gel types. 5.25% NaOCl had the highest electrical conductivity, whereas 2% chlorhexidine gel and RC-Prep gel had the lowest electrical conductivities among the five irrigants.

Conclusions

Different canal irrigants with different electrical conductivities may affect the accuracy of the Root ZX in perforated teeth.

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.

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.

In vivo comparison of the accuracy of two electronic apex locators

The aim of this study was to analyse in vivo the accuracy of two apex locators, Root ZX and Novapex, to determine the position of the apical constriction. Twenty-three human single-rooted teeth to be extracted for periodontal reasons constituted the experiment. Endodontic access was obtained and the apical constriction was determined by one of the apex locators after initial crown-down preparation. When the electronic marker indicated that the tip of the endodontic file was at the apical constriction, the teeth were filled with composite and then surgically removed. The presence of the endodontic file tip at the apical constriction was evaluated stereomicroscopically (30×) and confirming radiographs were exposed. The accuracy of Root ZX and Novapex was 91.7% and 81.8% respectively. Within the limits of this study, the evaluated apex locators have a similar clinical performance for the apical constriction location.

In vitro evaluation of the accuracy of two electronic apex locators

This study involves evaluating the accuracy of two electronic apex locators (EALs), Raypex and Neosono Co-pilot. Ten single-root human anterior teeth were used for the study. The crown was sectioned to gain access to the root canal. For each tooth, the reference (or control) length, corresponding to the actual length, was determined, after which all the teeth were measured independently. The results obtained with each EAL were in turn compared with the corresponding control length. The statistical analysis of the results showed that EAL reliability in detecting the apex varies from 80 to 85% for Neosono systems and 85 to 90% for the Raypex systems. Combined with a high observer concordance, these results suggest that electronic root canal measurement can be an objective and acceptably reproducible technique.