Working Length Of Root Canals Research Articles

Evaluation of the Accuracy in Four Electronic Apex Locators toward determination of working length of root canal: an in-vitro study

Evaluation of the Accuracy in Four Electronic Apex Locators toward determination of working length of root canal: an in-vitro study

Influence of the method for determining working length on the obturation level of primary molars.

Efficient working length determination is essential for a successful endodontic treatment. The purpose of the present study was to evaluate whether the method for determining the working length of root canals (radiographic or electronic) influences the obturation level of primary molars. Thus, a controlled, triple-blind, randomized clinical trial was conducted. Sixty-four children aged 6 to 9 years with an indication for primary molar pulpectomy were included. Participants were divided into two groups according to the method used to determine the working length of the root canals: (G1) radiographic and (G2) using an electronic apex locator. The study had 3 operators: #1 performed the clinical procedures, except the electronic measurement; #2 performed radiographic measurement and final evaluation of obturation level; and #3 performed eligibility criteria and electronic measurement. Adequacy of obturation level was evaluated based on the final conventional radiography and it was recorded as acceptable or unacceptable (short or overfilled). Data were analyzed with repeated measures logistic regression. There was no difference between the obturation level of primary molars measured by radiographic and electronic methods (p > 0.05). The other investigated variables (age, tooth type, dental arch position, last instrumentation file, and canal location) also did not influence the obturation level (p > 0.05). In conclusion, both measurement methods resulted in similar adequacy of obturation level in primary molars after pulpectomy.

Accuracy of Working Length Measured by Apex Locator and Digital Radiography

OBJECTIVE: The objective of this study was to compare the measurements of electronic and radiographic method of working lengths calculation with actual working length of root canals. Precise working length determination is the most important part for successful root canal procedure. The most commonly used methods to determine the working length in root canal treatment are radiography and electronic apex locator. METHODOLOGY: A cross sectional study was done over a period of 06 months in the Department of Operative Dentistry, Fatima Memorial Hospital, Lahore. Sixty patients who were recommended extraction of their premolar teeth with sixty canals were selected by convenience sampling. The Root ZX* apex locator was used to determine electronic working length exactly identifying the apical constriction. Reference points were identified and radiographic working length were determined 1mm short of radiographic apex. The teeth were extracted along with file cemented before extraction inside root canal. The actual length of the root canal was then calculated using the same files and reference point with 3.5X magnification. Pearson chi square test was applied to compare the apex locator and digital radiographic measurement with actual working length. RESULTS: The Root ZX® apex locator was 95% accurate to identify the apical constriction as compared 70% accuracy given by radiographs within 0.5 mm of the apex. CONCLUSION: Electronic apex locator was more accurate as compared to digital radiography in working length determination. KEYWORDS: Working length (WL), Electronic apex locators (EAL), Radiographic working length(RWL), Apical constriction (AC) HOW TO CITE: Khan GI, Khan MT, Ehsan S, Fayyaz A, Malik HA, Hussain S. Accuracy of working length measured by apex locator and digital radiography. J Pak Dent Assoc 2021;30(1):24-28.

Comparison Between Accuracy of Two Different Electronic Apex Locators in Determining Working Length of Root Canals: An In Vitro Study

Background: Accurate determination of the working length of root canals is an important factor for the success of endodontic therapy. Aim: Two different apex locators namely Propex Pixi (Dentsply) and Canal Pro (Coltene) are used to determine the working length of root canals and their results are compared to determine their accuracy. Material and Methods: Twenty extracted permanent single-rooted teeth are used for the study. To determine the working length of root canals of each tooth, two different types of electronic apex locators, Propex Pixi (Dentsply) and CanalPro (Coltene) are used and their results are compared. Result: There was a significant difference in accuracy between the two apex locators in determining the working length of root canals (p-value <0.05). Canal Pro was more accurate than Propex Pixi.

Root canal working length determination using Cone-Beam Computed Tomography

Introduction Cone-Beam Computed Tomography (CBCT) represents unique supporting diagnostic tool in all areas of dentistry as well as endodontics. One of the uses in endodontics is determining working length of the root canals-odontometry. The aim of this paper was to test the efficacy of CBCT application in determining working length of root canals. Methods Forty-three extracted human teeth were placed in three wax models shaped as a horseshoe. Preoperatively, CBCT model scanning (voxel size: 0.2 mm) was performed. Access cavities were prepared and working length determined by introducing expanders #08 into the root canal until the apical foramen. The length was measured using a micrometer odontometer. The CBCT working length was simply measured by following the line between the apical foramen and the selected reference point. Two experienced operators performed all measurements, independently. The t-test was used to compare the obtained values. Results CBCT measurements showed small deviation from manual measurements. The mean value of the absolute difference between CBCT measurements and manual measurements was 0.39 mm (0.25-0.74 mm). The results of the t test (t = 0.311; p = 0.757) showed that there was no statistically significant difference between the odontometry performed by the endodontic instrument and odontometry performed using CBCT. Conclusion the CBCT measurement is reliable method for determining working length of root canals. In 94.29% of examined teeth, discrepancies less than 1 mm were found, which was not of clinical significance.

Comparison of root canal length measurement methods in primary teeth

Objectives: The purpose of this study was to evaluate the accuracy of conventional radiography, intraoral digital radiovisiography and electronic apex locator in determining the working length of root canals in primary teeth (in-vivo) and to compare the results with scanning electron microscopy measurements (ex-vivo). Materials and Methods: This study was conducted on 50 primary molar teeth. Standard endodontic access cavity preparations were prepared and the actual length was calculated by calibrated investigators. Working lengths were determined by using conventional radiography, RVG and apex locator in a total of 116 root canals. After the extraction of the teeth, each canal length was determined by using SEM. Data were analysed statistically by using Oneway Anova, Tukey HDS, Student t test and Bonferroni tests. Results: The mean root length measurements with conventional radiography were significantly higher than apex locator, RVG and SEM. The accuracy of apex locator and RVG were higher than conventional radiography in determining the working length in primary teeth. Conclusions: The electronic apex locators provide an acceptable level of accuracy in determining root canal length in primary teeth. Clinical Relevance: The purpose of this study was to evaluate the accuracy of conventional radiography, intraoral digital radiovisiography and electronic apex locator in determining the working length of root canals in primary teeth and,to compare the results with scanning electron microscopy measurements.

Influence of Irrigant Solutions and Apex Locators in Working Length Determination

The objective of this study is to evaluate the accuracy of three apex locators using four irrigant solutions to determine the working length of root canals. Material and methods: thirty unirradicular teeth were used. Teeth were randomly divided into three groups, in order to establish the working length, using different apex locators: Raypex 6, Endo EZE and RootOR.

Comparison of working length determination using apex locator and manual method - ex vivo study

Background: Electronic apex locators can be a useful adjunct with a high level of accuracy for determining the real root canal length in clinical practice. Aim: The objective of this ex vivo study was to evaluate the accuracy of electronic apex locator for real working length determination in comparison with a manual method. Materials and Methods: Forty single-rooted teeth were used in this study. After coronal access, manual measurement of the real working length of each root canal was performed by placing a size 10 K-file, using as reference the exceeding of the file in the apical foramen. The file was retracted by 1 mm, and its extension was measured to determine the real working length. The electronic measurement of the working length was performed in the same teeth using the Joypex 5 electronic apex locator. Results: Data were submitted to statistical analysis (Wilcoxon-Mann-Whitney test, P > 0.05) and no significant difference was found between the electronic and manual methods (P > 0.05). Conclusions: It may be concluded that the electronic apex locator is a reliable and accurate method for determining the working length of root canals, optimizing the odontometric procedure in clinical practice.

Evaluation of the Joypex 5 and Root ZX II: an in vivo and ex vivo study

To evaluate in vivo and ex vivo the accuracy of the multifrequency electronic root canal length measurement device (ERCLMD) Joypex 5 and compare it with the Root ZX II. The ex vivo methodology for evaluation of the accuracy of ERCLMDs was also validated by comparison with in vivo results. Twenty single-rooted human teeth that were scheduled for extraction were selected. Working length measurements were performed in vivo with the Joypex 5 and Root ZX II. After the teeth were extracted, each canal was measured with the ERCLMDs ex vivo. Then, a size 15 K-file was used to determine the reference working length (RWL), which was established 0.5 mm from the major foramen by direct observation. The measurements of working length obtained with the different methods and ERCLMDs were compared by analysis of variance and Tukey's test at P < .05. Statistical correlations were also performed. No significant difference was observed between in vivo and ex vivo measurements or the different types of ERCLMDs. The Bland-Altman plot confirmed the agreement of different methods and ERCLMDs to measure canal length. The R(2) coefficient obtained in both situations, comparing the ERCLMDs, was close to 1, denoting a strong agreement between measurements obtained with the Joypex 5 and Root ZX II and between in vivo and ex vivo methodologies. The Joypex 5 and Root ZX II had similar accuracy in determining working length of root canals. The ex vivo methodology for evaluation of the accuracy of ERCLMDs was validated when compared with the in vivo results.

Shaping of the Root Canal Using Er:YAG Laser Irradiation

The purpose of the present study was to investigate the degree of Er:YAG laser irradiation at the apical area in vitro. Since the laser was developed, advancement of laser treatment has been seen in various fields. However, few reports exist on shaping of the root canal using Er:YAG laser irradiation. Six single-rooted human teeth were used. The working length of root canals was set at 6.5 mm, and they were enlarged to apical file size #25. An Er:YAG laser and cone-shaped irradiation tips (R135T and R200T) were used. Laser irradiation conditions were 30 m J, 20 pps, and water flow of 5 mL/min. Samples were irradiated three times for 10 sec each using each tip. To evaluate the cutting degree of horizontal area of the root canal, the laser-irradiated surfaces were observed using microfocus X-ray computed tomographic photography before and after every irradiation. The samples were observed under a scanning electron microscope. Measurement of pixels in an area was performed by image-editing software (Adobe Photoshop 7.0). Statistical analysis was performed using StatView (version 5.0). One-way ANOVA and the Tukey-Kramer tests were used; p<0.05 indicated statistical significance. When root canals were irradiated with R200T for 10 sec (p<0.05), a large amount of evaporation (0.12 ± 1.07 mm(2)) was acquired in their cut area compared with the other irradiation conditions. In scanning electron microscopic observation, there was no smear layer and the dentinal tubules were open. When the distance between the tip and root dentin was adjacent, the shaping of root dentin by Er:YAG laser irradiation was definitely observed.

An in vivo comparative evaluation to determine the accuracy of working length between radiographic and electronic apex locators

An in vivo comparative evaluation to determine the accuracy of working length between radiographic and electronic apex locators. The study was aimed at evaluating the accuracy of electronic apex locator, to determine the working length of root canal, and to compare it with the radiographic method of working length determination. A total of 20 teeth selected for the study had to go for extraction because of periodontal or orthodontic reasons. Access cavity was prepared and the clinical estimated working length (CEWL) was determined with 10-25 no. K-file. A radiograph was then taken for determining the radiographic estimated working length (REWL). For electronic measurement of root canal, a 10 no. K-file was advanced toward the apex until it reached a 0.5 mm short of apex as shown by the apex locator. After fixing the file with a light cured composite, the tooth was extracted, the tooth surface was then longitudinally grounded using straight fissure diamond bur until the root canal and the tip of the file were visible. The distance of file from the minor constriction was measured with help of stereomicroscope. The chi-square test was used for statistical analysis for this study. The chi-square test where χ² = 21.034 with P = 0.000 indicated that a significant difference exists among the groups. The electronic method showed highest number of cases with the working length at the minor constrictor. The electronic method for determining the working length of root canal was found to be more accurate than the radiographic method.

Evaluación in vitro de la exactitud del localizador apical miniapex (sybronendo)

The purpose of this study was to determine the accuracys grade of the mini apex locator in the location of the CDC when this it indicates the measure of 0.0mm, confirmed with the SEM. 84 root canals were taken from permanent extracted lower first molars for periodontics of prostodontics reasons this were separated of the distal roots, cut them to level of the enamel-cementum joint, with a carbide disk to low speed, to later on the COE was made using gates glideen burs # 2y 3, irrigating each one of them with NaOCl to 5.25% and later they were introduced sybronendo K flex files #0.8, 10, or 15 depending of the root canal diameter. The Asakos method was used for determine the work's length, followed step was to fit the files inside of the root canal with fluid resin, subsequently to proceeded to cut the filess handle with a and to observe the position of the D0 of the file with respect to the CDC with the SEM with a magnification of 400X. The results show that in the 85.7 %( 52 roots canals) of the samples the D0 of the file was between 0.0 -0.5mm of the CDC and the 14.3 %( 12 root canals) was for under of the CDC. Test showed no significant differences between measurements demonstrated like that the accuracy of Mini Apex locator in determining the working length of root canals during endodontic treatment.

Determination of working length of root canal

Background: This study was undertaken to determine the working length of root canal by microprocessor controlled impedance quotient apex locator and conventional radiographic method. Methods: Patients whose teeth were to be extracted were selected for this study. A total of 100 teeth in the same or different patients were identified. Biomechanical preparation of the canal was done for smooth negotiation of the entire canal. The electrode of the Root ZXTM was attached to the selected file and the length adjusted till the beep of the Root ZXTM indicated the apical foramen. The electrode was removed but the file was stabilized with the help of soft gutta percha. An intraoral periapical (IOPA) radiograph was taken using basic guidelines. The tooth was then extracted under local anaesthesia along with the file in the tooth. A window was cut on one surface of the root apex approximately 4mm from the apex to expose the root canal. The file tip was identified. The distance of the file tip from the apex was measured under 3X magnification and the reading recorded. Similarly the distance from the file tip to the radiographic apex was measured on the radiograph under magnification and the reading recorded. All the readings were tabulated. The actual distances measured between the extracted tooth, the electronic apex locator and on the radiograph were compared using a paired “t” test to determine the accuracy of each method in relation to the minor diameter. Result: It was observed that the radiographic method had a significant variation from the electronic method when compared to the actual measurement on the extracted tooth. Conclusion: The electronic method is a more accurate method as compared to radiographic method for determination of working length of the root canal.

SIXTH GENERATION ADAPTIVE APEX LOCATOR

SUMMARY: A comparative analysis is made which is grounded on literary data concerning the advantages and disadvantages of apex locators of various generations that have been created following two different principles /19, 28/. The PURPOSE of this study is to create a method and a device that combine the established advantages of fourth and fifth generation instruments. While measuring the working length of the root canals of 30 extracted human teeth /dry and filled with animal blood and sodium hypochlorite/, experimental research work was carried out which has served as a basis for creating both a method and an adaptive apex locator that combine the advantages of the two previous generations of appliances. The prolonged direct and juxtaposing studies have made it possible to create a steady algorithm for adapting the method for measuring the working length of the root canal depending on the canal’s moisture characteristics. The method has been implemented in the apex locator of the so called sixth generation – the adaptive type. Measurement with the adaptive apex locator has made it possible to eliminate the necessity of drying or moistening of the canal, as well as to achieve high degree of measurement precision in the presence of blood, of additionally imported liquid /sodium hypochlorite/, or while manipulating dry canals. Clinical observations are yet to come that will help assess the device’s ability to determine the working length of root canals under various clinical conditions and situations.

Effect of Water Ratio in Alginate-mounted Endodontic Models on Electronically Determined Working Length of Root Canals

Background/Purpose. To evaluate whether the water content in alginate endodontic models affects the accuracy of the Root ZX apex locator in determining the working length of root canals. Methods. Twenty-nine extracted single-rooted teeth were embedded in alginate models and divided into two groups. Group A (15 teeth) was stored in a completely sealed box and placed in an incubator so that the humidity level would reach 100%. Group B (14 teeth) was stored in a box without a cover to simulate natural humidity. Models in both groups were stored in a 27℃ incubator for up to 120 hours. The percentage of water content in alginate was measured by weighing the invested models at different measuring time points. The distance from the incisor edge or cusp tip to the major foramen of the root apex indicated the actual tooth length (AL).The electronically determined length (EDL) was measured by a K file advanced into the root canal to just beyond the major foramen, and then withdrawn counter-clockwise until a flashing bar appeared at the ”APEX” of the Root ZX. The measurements were performed at different time intervals. The subtraction difference (SD) between AL and EDL was recorded for each tooth in each group. The SD values at five different measuring time points in each group were then compared by a Student's t-test. Results. No significant difference in SD was observed in either group when the water content of alginate remained within the range of 73% to 62.5%. An average constant subtraction difference of 0.30 mm was found in group B. Conclusion. The Root ZX apex locator provided accurate and stable working length measurements when the water content in the alginate invested models remained within the range of 73% to 62.5%.

Evaluation of working length determination methods: An in vivo / ex vivo study

This comparative study was done to determine the accuracy in measuring the working length of root canal using tactile method, electronic apex locator and radiographic method, in vivo and comparing the lengths so measured to the actual working length, ex vivo, after extraction. Thirty single-rooted teeth scheduled for extraction were selected for the study. After obtaining the consent from patients, a preoperative radiograph was taken and access opening was done. Working length was determined by tactile method, by using Ingle's radiographic method and by using a Foramatron-IV digital apex locator. The teeth were then extracted and the actual working length was determined by placing an endodontic file in the root canal 0.5 mm short of the apex. The results indicated that among the three methods, the electronic apex locator showed the highest accuracy and the highest reliability for working length determination.

Comparison of radiographic and electronic working lengths

The purpose of this study was to compare the ability of radiographic and electronic methods to determine reliably the location of the apical constriction. The working length of root canals in human cadaver teeth was determined by positioning an endodontic file at the apical termination point as indicated by an apex locator. These same teeth were radiographed at various angles with the file in place. The radiographs were evaluated by five examiners to determine a radiographic termination point for each canal. Teeth were extracted and examined histologically to determine the ideal termination point. The deviations of the two experimental termination points from the ideal termination point were compared. The mean of the absolute value of the deviations from the apical constriction for the apex locator was significantly less (p < 0.05) than that for the radiographic method. Thus, the method using the apex locator was slightly more reliable.

The use of E‐speed film for root canal length determination

This study compared the use of D-speed and E-speed dental X-ray film for assessing the working length of root canals. Root canal files of varying size (ISO 06, 08, 10 and 15) were placed in the root canals of a maxillary molar and a mandibular molar in a dried skull and mandible. Files were set at various lengths relative to the radiographic apex. The X-ray projections were kept constant. Exposure settings for the two film types that gave comparable radiographic density were selected. Films were developed manually under standardized conditions. A total of 48 films of each type were examined at various magnifications by four trained examiners for the estimation of distance between the file tip and radiographic apex. There were no differences between examiners in estimating working length. The effect of file size, root and magnification were also not significant. The differences between the film types were not significant (P > 0.05). It is concluded that clinicians should use E-speed film instead of D-speed film for root canal length measurement, because the exposure time was reduced by over 40% but the quality of the radiographic image was not significantly different.

Clinical investigation of measuring working lengths of root canals with an electronic device and with digital-tactile sense

The accuracy of an electronic device in locating the working length of root canals, without the use of radiographs, was compared with lengths determined by digital-tactile sense. Although the concept of the Sono-Explorer (an electronic device for measuring the length of root canals) is good, the predictability of accuracy of its intended purposes was less reliable than that with digital-tactile sense. Electronic instruments have been introduced for use in endodontics to measure the length of root canals and, hence, decrease the number of radiographs taken. This investigation was designed to evaluate the validity, predictability of accuracy, and value of such a device. The objectives were to determine the working length of root canals and to detect accessory or lateral canals electronically. Four investigators collectively tested 50 teeth with the electronic device and 50 teeth comparatively with digital-tactile sense. The results were verified with wire-grid radiology. Although the concept is good, the predictability of accuracy of its intended purposes was less reliable than that with digital-tactile sense. On the basis of the reported findings, the electronic device should not replace radiographic control in endodontic therapy as a measuring device. Further research and modifications are indicated. The accuracy of an electronic device in locating the working length of root canals, without the use of radiographs, was compared with lengths determined by digital-tactile sense. Although the concept of the Sono-Explorer (an electronic device for measuring the length of root canals) is good, the predictability of accuracy of its intended purposes was less reliable than that with digital-tactile sense. Electronic instruments have been introduced for use in endodontics to measure the length of root canals and, hence, decrease the number of radiographs taken. This investigation was designed to evaluate the validity, predictability of accuracy, and value of such a device. The objectives were to determine the working length of root canals and to detect accessory or lateral canals electronically. Four investigators collectively tested 50 teeth with the electronic device and 50 teeth comparatively with digital-tactile sense. The results were verified with wire-grid radiology. Although the concept is good, the predictability of accuracy of its intended purposes was less reliable than that with digital-tactile sense. On the basis of the reported findings, the electronic device should not replace radiographic control in endodontic therapy as a measuring device. Further research and modifications are indicated.