An in vivo evaluation of Root ZX electronic apex locator

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

Background

Accurate determination of the working length (WL) is crucial for successful endodontic treatment. Various methods, including radiography and electronic apex locators (EALs), are employed for WL measurement, each with its advantages and limitations.

Aim

This study aimed to compare the accuracy of WL determination using conventional radiography and the Root ZX Mini EAL against an ex vivo gold standard method.

Materials and Methods

Fifty single-rooted teeth scheduled for extraction were included. WLs were determined using radiography (Grossman's method) and the Root ZX Mini EAL. An ex vivo method served as the gold standard with WL carried out on extracted teeth under a stereomicroscope. Statistical analysis included Paired samples t-test, Chi-square test, and Bland-Altman plots.

Results

The mean WL values were comparable among methods, with slight variations in precision. The Root ZX Mini EAL demonstrated significantly lower mean absolute error compared to radiography (P < 0.001). Accuracy within ± 0.5 mm and ± 1 mm tolerance ranges favored the EAL over radiography (P = 0.04 and P = 0.004, respectively).

Conclusion

The Root ZX Mini EAL exhibited superior accuracy and lower error rates in WL determination compared to radiography. Integrating EALs alongside radiographic techniques is recommended to optimize WL precision in clinical practice.

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

Aim

To compare the effectiveness of Apex Locators and Endomotor with built-in Apex Locators for determining the working length in root canal treatment.

Methods

A total of 120 patients were randomly assigned to three groups: Group 1 (Root ZX Mini Apex Locator), Group 2 (Minipex Apex Locator), and Group 3 (Endopilot Endomotor with built-in Apex Locator). Working length was determined using respective devices, followed by canal preparation and radiographic confirmation with a master cone.

Results

There was no statistically significant difference in working length determination between Apex Locators and Endomotor with built-in Apex Locators. Acceptable working length was achieved in 105 out of 120 cases.

Conclusion

The Root ZX Mini, Minipex, and Endopilot demonstrated comparable efficacy in determining working length during root canal treatment. These devices offer reliable alternatives to traditional radiographic methods, providing clinicians with accurate measurements and contributing to successful treatment outcomes.

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

INTRODUCTION

This bibliometric review analyzed the research trends and main characteristics of articles related to Electronic Apex Locators (EALs).

METHODS

The search was conducted in November 2023 on the Web of Science Core Collection. Narrative and systematic reviews, observational and intervention studies, laboratory, and clinical studies were included. Two researchers selected the articles and extracted the number of citations, year of publication, journal, study design, theme, country, continent, institutions, author, and keywords. Collaborative networks were generated using the VOSviewer software. The relationship between data were determined by Spearman's correlation.

RESULTS

The search resulted in 374 articles, of which 294 were included. Most cited article had 175 citations. The most prevalent journal was the Journal of Endodontics (n = 84). The predominant study design was the laboratory-based (n = 223). The predominant theme was the EALs accuracy (n = 175). Piasecki L was the author with the highest number of articles (n = 11). Only 8.16% of the studies were conducted in deciduous teeth. The country with the most studies was Brazil (n = 46). Asia (n = 107) was the continent with the highest number of publications. There was a weak positive correlation between the number of citations and impact factor (rho = .294), and a strong negative correlation between citations and year of publication (rho = -.710).

CONCLUSIONS

The majority of articles were laboratory-based studies conducted on permanent teeth, focusing on the accuracy of EALs. Future studies should prioritize research on deciduous teeth, systematic reviews, and, notably, clinical trials.

Comparative evaluation of the accuracy of six different apex locators in working length determination of molars using intraoral periapical radiographs: An in vivo study

Context

One of the crucial steps in endodontic treatment is determining the working length (WL). There are various methods for performing this procedure, one of which is an electronic apex locator (EAL) measurement.

Aims

The aim of this study was to determine the accuracy of six EALs, i.e.. Root ZX, Root ZX Mini, Propex PiXi, Innvopex-1, Woodpex III, and Raypex 6 for WL estimation in the mandibular first molars.

Material and Method

The study included 180 root canals with symptomatic irreversible pulpitis, divided into six groups using different apex locators. WL determination was compared with intraoral periapical radiographs. Results were categorized as accurate, short, or long. The data were statistically analyzed.

Results

ROOT ZX had an accuracy of 96.7%, Root ZX Mini had an accuracy of 93.3%, PiXi had an accuracy of 90.0%, Innvopex-1 had an accuracy of 90.0%, Woodpex III had an accuracy of 86.7%, and Raypex 6 had an accuracy of 83.4%, respectively. There was a statistically nonsignificant difference between groups (P < 0.05).

Conclusion

Newly developed apex locators, such as the Innvopex-1, have shown accuracy comparable to well-established EALs like the Root ZX. This highlights the importance of conducting more extensive, large-scale research to confirm and validate their effectiveness.

Variations in the morphology of apical constriction affecting electronic readings: An in vitro investigation using 3D-printed tooth models

We investigated the interference of apical constriction position and diameter on the accuracy of electronic apex locators using 3D-printed tooth models. Single-rooted tooth models with the same length, canal taper and major foramen, but variation in apical constriction position or size, were designed and 3D-printed. A mounting model was custom-made for precise measurement of both marks (0.5 and APEX/0.0) of two electronic apex locators. The electronic measurements of both devices were correlated significantly to the major foramen rather than apical constriction. The mean measurements of the group with 0.45 mm in apical constriction width were significantly shorter than those of the other groups for both marks of the two devices (p < 0.05). The variations in apical constriction position and width negatively affected the precision of the 0.5 mark of the tested devices. The 0.0 or APEX mark was consistently located the major foramen.

Working length variation during multiple-visit endodontic treatment: An observational study

This study investigated variation in working length during multiple-visit endodontic treatment. Patients (N = 106) with pulpitis or pulp necrosis, with or without apical periodontitis, were included. During the first appointment, glide path was performed with ProGlider and shaping with ProTaper Next. Working length was detected four times. Working length was then re-recorded prior to filling during the second appointment and a 0.5 mm threshold was selected as the minimum clinically meaningful variation. A logistic regression model was used to evaluate the impact of tooth anatomy, preoperative pulp status, apical periodontitis and lesions of endodontic origin on working length variation. Working length varied between first and second appointments in 34% of patients. The presence of apical periodontitis was the only variable significantly associated with variation in working length (p = 0.011). These data suggest that working length should be re-checked prior to root canal filling to prevent procedural errors.

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.

Improved mineralization of dental enamel by electrokinetic delivery of F- and Ca2+ ions

This in vitro study evaluated the effects of the infiltration of F^- and Ca²⁺ ions into human enamel by electrokinetic flow (EKF) on the enamel microhardness and F^- content. Sound human enamel ground sections of unerupted third molars were infiltrated with de-ionized water by EKF and with F^- ion by EKF respectively. All samples were submitted to two successive transverse acid-etch biopsies (etching times of 30 s and 20 min) to quantify F^- ion infiltrated deep into enamel. Remarkably, sound enamel showed a large increase in microhardness (MH) after infiltration of NaF (p < 0.00001) and CaCl₂ (p = 0.013) by EKF. Additionally, NaF-EKF increased the remineralization in the lesion body of artificial enamel caries lesions compared to controls (p < 0.01). With the enamel biopsy technique, at both etching times, more F^- ions were found in the EKF-treated group than the control group (p << 0.05), and more fluoride was extracted from deeper biopsies in the NaF-EKF group. In conclusion, our results show that EKF treatment is superior in transporting Ca²⁺ and F^- ions into sound enamel when compared to molecular diffusion, enhancing both the mineralization of sound enamel and the remineralization of artificial enamel caries.

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.

Reliability and accuracy of dental MRI for measuring root canal length of incisors and canines: a clinical pilot study

To evaluate whether high-resolution, non-contrast-enhanced dental MRI (dMRI) can reliably and accurately measure the canal length of incisors and canines compared with cone-beam computed tomography (CBCT). Three-Tesla dMRI was performed in 31 participants (mean age: 50.1 ± 14.2 years) with CBCT data. In total, 67 teeth were included (28 from the upper jaw and 39 from the lower jaw; 25 central incisors, 22 lateral incisors, and 20 canines). CBCT and dMRI datasets were reconstructed to visualize the root canal pathway in a single slice in the vestibulo-oral (V-O) and mesio-distal (M-D) direction. Root canal length was measured twice by two radiologists using dMRI and CBCT. Data were statistically analyzed by calculating intraclass correlation coefficients (ICCs) and performing Bland–Altman analysis. The reliability of dMRI measurements was excellent and comparable to that of CBCT measurements (intra-rater I/intra-rater II/inter-rater was 0.990/0.965/0.951 for dMRI vs. 0.990/0.994/0.992 for CBCT in the M-D direction and 0.991/0.956/0.967 for dMRI vs. 0.998/0.994/0.996 for CBCT in the V-O direction). According to Bland–Altman analysis, the mean (95% confidence interval) underestimation of root canal lengths was 0.67 mm (− 1.22 to 2.57) for dMRI and 0.87 mm (− 0.29 to 2.04) for CBCT in the M-D direction/V-O direction. In 92.5% of cases, dMRI measurements of canal length had an accuracy within 0–2 mm. Visualization and measurement of canal length in vivo using dMRI is feasible. The reliability of dMRI measurements was high and comparable to that of CBCT measurements. However, the spatial and temporal resolution of dMRI is lower than that of CBCT, which means dMRI measurements are less accurate than CBCT measurements. This means dMRI is currently unsuitable for measuring canal length in clinical practice.

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.

Comparison of Radiovisiography, an Apex Locator and an Integrated Endomotor-inbuilt Apex Locator in Primary Teeth Endometrics

Aim and objective

To compare the accuracy of radiovisiography (RVG), Root ZX mini Apex locator, and Endo radar's inbuilt Apex Locator during working length determination determination in primary teeth with the actual/direct canal length.

Materials and methods

58 primary teeth indicated for extraction in children of age group 4-12 years were selected. RVG, Root ZX mini Apex Locator, and Endo radar's Apex Locator were used to determine the working length intraorally. Following extraction of the teeth, the actual working length was determined with magnifying loupes (2.5×) using a K-file and an endodontic ruler. The data was tabulated and statistically analyzed.

Results

84 canals (58 teeth) were evaluated and Root ZX mini Electronic Apex Locator (EAL) showed no statistically significant difference with the actual measurement (p = 0.18) whereas Endo radar and RVG showed statistically significant difference. Endo radar underestimated, while RVG overestimated the working length. The most accurate method for working length measurements of the root canals in primary teeth was Root ZX mini EAL, followed by Endo radar and the least accurate was RVG.

Conclusion

The Root ZX mini Apex Locator showed the most promising results and had an excellent degree of agreement with actual working length, followed by Endo radar and RVG.

How to cite this article

Khan SA, Khanna R, Navit S, et al. Comparison of Radiovisiography, an Apex Locator and an Integrated Endomotor-inbuilt Apex Locator in Primary Teeth Endometrics. Int J Clin Pediatr Dent. 2022;15(S-1):S18-S21.

Effect of Sodium Hypochlorite Concentration on Electronic Apex Locator Reliability

This ex vivo study aimed to measure the performance of an electronic apex locator (EAL) in the presence of sodium hypochlorite irrigants with different concentrations. Two EALs (Root ZX Mini and Locapex 6) were used to locate the apical foramen in 10 extracted single-rooted teeth in the presence of 0.5%, 2.5% and 5% sodium hypochlorite. Visual working lengths were also determined using #10 K-file under a microscope before the electronic measurements were made. The performance of both EALs was compared for the electronic working lengths determined under the different concentrations of sodium hypochlorite. A multiple-way ANOVA and PLSD Fisher’s test with an α risk fixed at 5% were conducted. There were no statistical differences in the working lengths determined by both EALs between the three groups with different concentrations of sodium hypochlorite and their visual control measurements. When a ± 0.5 mm margin was applied, the Root ZX Mini and the Locapex 6 presented 88% and 83% accuracy, respectively. Sodium hypochlorite concentration in irrigants does not affect the accuracy and reliability of either the Root ZX Mini or the Locapex 6. Electronic apex locators are reliable with any concentration of sodium hypochlorite irrigants.

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.

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.

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.

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.

The Accuracy of a New Cone-beam Computed Tomographic Software in the Preoperative Working Length Determination Ex Vivo

INTRODUCTION

This study investigates the accuracy of 3D Endo software (Dentsply Sirona, Salzburg, Austria) to determine the working length when using preoperative cone-beam computed tomographic (CBCT) scans of extracted teeth, compared with conventional CBCT software and an electronic apex locator (EAL).

METHODS

CBCT scans of 30 premolars were obtained. Using OnDemand3D software (Cybermed, Seoul, Korea), the measurement obtained from the coronal reference to the apical foramen (AF) was recorded as the conventional CBCT length. Then, using 3D Endo software (Dentsply Sirona), the suggested length (3D-SL) and the operator-adjusted length (3D-OL) were obtained. Teeth were accessed, and the actual length was measured. Finally, the teeth were embedded in alginate to obtain the electronic length (EL) using the EAL Root ZX (J Morita, Tokyo, Japan). The means of the absolute values and the percentages of distribution of the tested measurement methods were compared to the actual length.

RESULTS

No difference was found regarding the mean measurements (analysis of variance, P > .05). All the CBCT measurements presented a high reliability (Dahlberg's formula). The measurements within a ±0.5-mm range from the AF were 86.6% for the 3D-SL, 80% for the 3D-OL and EL, and 73.3% for the CBCT length. The EL presented significantly fewer underestimated measurements (P < .05). The 3D-OL and 3D-SL presented significantly fewer measurements beyond the AF (P < .05).

CONCLUSIONS

The preoperative working length determination using 3D Endo was reliable and similar to conventional CBCT software. However, the combined use of CBCT with an EAL is required to increase the accuracy in the location of the AF.

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.

Accuracy of Working Length Determination using NovApex and Root-ZX Apex Locators: An in vitro Study

INTRODUCTION

This ex vivo study evaluated the accuracy of the Root-ZX electronic apex locator (EAL) (J. Morita, Tokyo, Japan) and the NovApex (Forum Technologies, Rishon Lezion, Israel) in determining the working length (WL) during endodontic treatment.

MATERIALS AND METHODS

Forty extracted single-rooted human teeth were selected for this study. The actual WL was measured with visual technique by a size #15 k-file under magnification. Then, the canal lengths were measured electronically with both Root-ZX and NovApex apex locators within ±0.5 and ±1 mm. Mean percentage of data was analyzed between groups using paired t-test, with a statistically significant level of p < 0.05.

RESULTS

The accuracy of NovApex apex locator was 85% within ±0.5 mm and 92.5% within ±1 mm. The accuracy of Root-ZX apex locator was 70% within ±0.5 mm and 97.5% within ±1 mm. There was no significant difference between the accuracy of the two EALs.

CONCLUSION

Both the NovApex and Root-ZX EALs are useful for measuring the WL with high accuracy.

CLINICAL SIGNIFICANCE

Given the importance of accurate WL determination in the success of endodontic treatments, the accuracy of different apex locators should be evaluated.

Controversies in Endodontics

Diseases of the dental pulp often have an infectious origin, and treatments are aimed to control infections of the root canal system. Endodontic treatment principles originally evolved on the basis of trial and error, and only in recent decades have scientific methods been adopted to support clinical strategies. Yet, relevant research on the disease processes, their diagnoses, and efficient treatment are rare in the endodontic literature. Hence, the advancement of biologically based knowledge significant to clinical endodontics has been slow. Therefore, many differences of opinion still prevail in this field of dentistry. This review highlights and analyzes the background of some of the more heavily debated issues in recent years. Specifically, it deals with disagreements regarding the clinical management of pulpal exposures by caries in the adult dentition, definitions of success and failure of endodontic therapy, and causes of and measures to control infections of the root canal system. Clearly, a most apparent gap in the published endodontic literature is the lack of randomized clinical trials that address the more significant controversial matters relating to the management of pulpal wounds, medication, and the number of appointments required for the treatment of infected root canals. However, trials in endodontics require extremely long follow-up periods if valid conclusions are to be generated. Therefore, it is not to be expected that there will be rapid solutions to these issues in the foreseeable future.

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.

Working Length Determination Using Cone-Beam Computed Tomography, Periapical Radiography and Electronic Apex Locator in Teeth with Apical Periodontitis: A Clinical Study

Introduction:

The purpose of this clinical study was to compare the accuracy of working length (WL) determination using cone-beam computed tomography (CBCT), conventional periapical radiographies and electronic apex locator.

Methods and Materials:

This study was conducted during root canal treatment of 19 patients with a total of 30 single-rooted teeth diagnosed with apical periodontitis. After taking the initial parallel periapical radiographies, the initial file was advanced into the canal until the WL was detected by the apex locator. Subsequently, the WL was measured and WL radiographies were taken with the file set in the canal. Afterwards, CBCT images were acquired. These three measurements were tabulated and compared and the data were analyzed using the Friedman test. The level of significance was set at 0.05.

Results:

The mean values for WL determination by electronic apex locator, periapical radiograph and CBCT images were 22.25, 22.43 and 22.65, respectively which was not statistically significant (P>0.05).

Conclusion:

Working length determination using CBCT images was precise when compared to radiographic method and electronic apex locator.

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.

Accuracy of an electronic apex locator in the retreatment of teeth obturated with plastic or cross-linked gutta-percha carrier-based materials: an ex vivo study

INTRODUCTION

This ex vivo study evaluated the accuracy of the Root ZX electronic apex locator (EAL) (J Morita Corp, Kyoto, Japan) in determining the working length during retreatment of canals sealed with 2 different carrier-based obturating materials (ProTaper Obturator [Dentsply Maillefer, Ballaigues, Switzerland] and GuttaCore [Dentsply Maillefer]) and also evaluated whether they influenced its accuracy differently.

METHODS

Fifty extracted single-rooted human teeth with sound apices were selected for the study. We measured canals with the direct visual technique using a #10 K-file and shaped them with ProTaper Universal instruments (Dentsply Maillefer) up to this predetermined length. After instrumentation, we determined the canal length again using the visual technique (direct length [DL]). This value was considered the "reference point." Specimens were then placed in a tooth holder (Pro-Train; Simit Dental, Mantova, Italy), and the canal length was electronically measured (electronic length 1 [EL1]). Specimens were then obturated with ProTaper Obturators (group 1, n = 25) and GuttaCore (group 2, n = 25). Seven days later, a new electronic length was determined (electronic length 2 [EL2]) during retreatment procedures in the presence of the obturating material. EL1 and EL2 values were compared with DL using the Bland and Altman method. The different influences of the tested materials on the accuracy of the EAL were calculated with repeated measures analysis of variance.

RESULTS

Both EL1 and EL2 values provided a statistically significant overestimation of the actual canal length (DL [P < .05]), with the EL2 values higher from DL. The 2 different materials did not influence the accuracy of the EAL differently (P = .486).

CONCLUSIONS

The measurements obtained with the EAL tested during orthograde retreatments can lead clinicians to overinstrumentation and consequent overfilling of the endodontic space.

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.

An anatomical investigation of the mandibular second molar using micro-computed tomography

PURPOSE

An understanding of root anatomy is an important foundation for providing successful endodontic treatment. The aim of this study was to use micro-computed tomography (micro-CT) to investigate the root anatomy of the mandibular second molar.

METHODS

Eighteen mandibular second molars were scanned using micro-CT. Images were reconstructed, and measurements and observations were recorded regarding pulpal floor anatomy, canal configuration, root wall thickness along the root, presence of calcifications in the pulp chamber and in canals, and apical anatomy.

RESULTS/CONCLUSIONS

The most frequently found mesial root canal configuration was Vertucci Type 7 (1-2-1-2), which was seen in 33.3% of samples. Distal canals were most frequently Vertucci Type 1 (one canal), with 61.1% of samples showing this configuration. 11.1% of samples had two canals, 44.4% of samples had three canals, 33.3% of samples had four canals, and 11.1% of samples had five canals at some point along the length of the roots. Average root wall thickness between the mesiobuccal canal and the furcation was 1.23 mm. Mesiolingual canal root wall thickness was on average 1.29 mm, and the distal root furcation wall thickness averaged 1.41 mm. 77.8% of samples had calcifications present in both the pulp chamber and within the canals.

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.

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.

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

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

Accuracy of the Dentaport ZX apex locator for working length determination when retreating molar root canals

The aim of this study was to evaluate the accuracy of the Dentaport ZX apex locator for working length determination during root canal retreatment of mandibular molars. Fifteen extracted mandibular first molars with separate mesial canals and apical foraminae and one distal canal were selected. The mesiobuccal and distal canals were investigated; the length with the file tip at the major diameter was defined as the tooth length (TL). The canals were prepared with ProTaper files to 1 mm short of this and filled with gutta-percha and AH Plus sealer. One week later, the root fillings were removed using ProTaper retreatment files. Tooth length was remeasured and recorded as the retreatment tooth length (RTL). Then electronic measurements were taken at the major (electronic apex locator (EAL) major) and minor (EAL minor) foraminae as suggested by the instrument display. These lengths were compared with RTL and measurements 0.5 and 1 mm short of this distance. For both canals, no significant difference was found between RTL and EAL major, and 0.5 mm short of RTL and EAL minor (P > 0.05). There were significant differences found between all other readings. The Dentaport ZX could not detect the minor foramen accurately but was able to indicate the major foramen in molars undergoing a root canal retreatment procedure.

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.

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.

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.