Root Canal Length Determination Research Articles

Comparison between electronic and radiographic method for the determination of root canal length in primary teeth

There are few researches in literature that mention the use of the apex locator in deciduous teeth and working length is obtained through radiographies. Objective: The purpose of this research was to compare the radiographic and the electronic method to obtain the working length in deciduous molars. Material andmethods: Twelve molar teeth were used. The specimens in the visual method had their root length measured through the passive insertion of a 10 K-file with a silicone stop within root canal until its tip was seen at the apical foramen. The working length was measured through radiographs or using the apex locator Root ZX II. The mean between the examiners was submitted to the variance analysis (ANOVA). Results: Statistically significant differences were found between the visual method and the radiographic method (p < 0.001). There was no significant difference between the working length measurements in visual method and those obtained with the apex locator (p = 0.1319). Conclusion: The apex locator is indicated as a clinical implementation for endodontic treatment in primary teeth.

An in vitro comparison of root canal length determination by DentaPort ZX and iPex apex locators.

Aim:The aim of the present study is to evaluate and to compare the accuracy of two electronic apex locators (EALs): DentaPort ZX and iPex, at a position 0.5 mm short of the apical foramen.Materials and Methods:Thirty single-rooted, mandibular premolar teeth were selected. Standard access cavities were prepared and the actual length (AL) was calculated. The samples were then embedded in alginate and the electronic measurements were determined and recorded.Results:The results obtained showed that in determining the root canal length with a tolerance level of ±0.5 mm, i.e., AL ± 0.5 mm, DentaPort ZX was accurate in 93.3% of the samples and iPex was accurate in 90% of the samples at a position 0.5 mm short of the apical foramen.Conclusion:A strong correlation was seen between the two electronic methods and AL and also in between the two EALs, showing the possibility of their use to measure the root canal length. No statistically significant difference was found between both the apex locators.

Accuracy of apex locator for root canal length determination of deciduous molars compared to conventional radiograph

Background: To assess whether apex locators are accurate in determining the root canal length in resorbing roots of deciduous tooth compared to the conventional radiographic method. Materials and Methods: Samples for the study included 30 primary maxillary and mandibular molar root canals in children of age group 5 to 12 years. Root canal lengths were determined with Conventional radiographs, Apex locator and direct measurements using stereomicroscope. Results: When the measurements from radiograph and apex locator were compared with direct measurements, they were non-significant with P value of 0.342 and 0.266 respectively and F value of 0.396 and 0.303, respectively. Conclusions: Apex locator and conventional radiograph both are proven to be accurate in working length determination in primary molars. Apex locators can thus be used in resorbing root canals of deciduous molars obtaining good results with no radiation hazard and processing difficulties. Clinical Relevance to Interdisciplinary Dentistry Working length determination is one of the crucial steps for the final outcome of the endodontic procedure Apex locators work well in fully formed roots, but is it the same in cases of resorbing roots especially as seen in deciduous teeth The answer to the same question may be relevant in roots with external root resorption or in an immature root

Endodontic Working Length Measurement with Preexisting Cone-Beam Computed Tomography Scanning: A Prospective, Controlled Clinical Study

IntroductionThe determination of root canal length is a significant outcome predictor for endodontic treatments. The aim of this prospective, controlled clinical study was to analyze endodontic working length measurements in preexisting cone-beam computed tomography (CBCT) scans and to compare them with clinical root canal length determination by using an electronic apex locator (EAL). MethodsAll included patients had received a CBCT scan independent of the present study and needed root canal treatment of at least 1 anterior tooth visible in the field of view. Clinically, the root canal length was measured with an EAL by an endodontist. This measurement was compared with the root canal length as measured on vestibulo-oral and mesiodistal CBCT sections by an examiner not involved in the endodontic treatment. The CBCT measurements were repeated once for analysis of intrarater reliability. ResultsForty anterior teeth in 30 patients (13 women and 17 men; average age, 44 years; range, 18–80 years) were included in this investigation. The Pearson correlation coefficient (r) comparing the root canal length measurements by using CBCT and EAL was 0.97. In addition, high intrarater reliability for the CBCT measurements was found (r = 0.99). ConclusionsThis prospective, controlled clinical study showed that limited CBCT scans can be used for endodontic working length measurements. Future studies are needed to evaluate whether preexisting CBCT scans could replace initial periapical radiographs and working length periapical radiographs.

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.

Radiographic versus electronic root canal working length determination

The aim of this ex vivo study was to compare the accuracy of radiographic and electronic root canal length determination methods, compared with actual root canal length obtained with stereomicroscope. Thirty extracted single-rooted permanent teeth were used for this study. After access preparation, actual length (AL) of the root canal were determined for each tooth by inserting a #15 file until the tip of the file was visible at the apical foramen under a stereomicroscope. The radiographic working length determination was determined with a digital radiographic system and for the electronic measurement all teeth were embedded in an alginate model to test apex locator in-vitro. Data was analyzed using the descriptive statistic and intraclass correlation coefficient. No significant difference was found between the radiographic and electronic root canal working length determination (P>0.05). The percentage of electronic measurements within ± 0.5 mm to the apical constriction was 93.34% and 90% for radiographic methods within ± 0.5 mm of all cases compared with AL. The present ex vivo study showed that electronic root canal working length determination is not superior to radiographic methods. Both methods provided a good performance in determining the root canal working length.

Electronic working length determination in primary teeth by Propex and Digital Signal Processing

The purpose of this study was to evaluate the accuracy of electronic apex locators Digital Signal Processing (DSP) and ProPex, for root canal length determination in primary teeth. Fifteen primary molars (a total of 34 root canals) were divided into two groups: Group I - without physiological resorption (n = 16); and Group II - with physiological resorption (n = 18). The length of each canal was measured by introducing a file until its tip was visible and then it was retracted 1 mm. For electronic measurement, the devices were set to 1 mm short of the apical resorption. The data were analysed statistically using the intraclass correlation coefficient (ICC). Results showed that the ICC was high for both electronic apex locators in all situations - with (ICC: DSP = 0.82 and Propex = 0.89) or without resorption (ICC: DSP = 0.92 and Propex = 0.90). Both apex locators were extremely accurate in determining the working length in primary teeth, both with or without physiological resorption.

An ex vivo comparison of root canal length determination by three electronic apex locators at positions short of the apical foramen

The aim of this study was to evaluate the precision of working length determination of 3 electronic apex locators (EALs): Root ZX, RomiApex D-30, and Ipex at 0.0 mm, at the apical foramen (AF), and at 1.0 mm short of the AF. Thirty-eight mandibular premolars had their real lengths previously determined. Electronic measurements were determined at 1.0 mm, followed by measurements at 0.0 mm, performed in triplicate. Precision of devices at 1.0 mm and 0.0 mm were: 94.7% and 97.4%, respectively (Root ZX); 78.9% and 97.4% (RomiApex D-30); and 76.3% and 97.4% (Ipex). Although no statistical differences were observed between the EALs at 0.0, at 1.0 mm Root ZX performed significantly better than the others. The EALs had acceptable precision when measuring the working length at the AF. However, when used at levels short of the AF, only Root ZX did not suffer a significant negative effect on precision.

Ex vivo performance of five methods for root canal length determination in primary anterior teeth

To evaluate in a laboratory setting the performance of five methods for the determination of root canal length in primary anterior teeth. Twenty extracted primary incisors, with at least two-thirds of the root, were used. After access cavity preparation, the teeth were embedded in alginate mixed with 0.9% sodium chloride solution. One operator determined root canal length using tactile sense (T), conventional radiography (RAD), tactile sense and conventional radiography (T + RAD), digital radiography (RDIG) and Root ZX electronic apex locator (EAL) methods. Next, the actual length (AL) was visually determined using a K-file from the coronal reference to the apical foramen or apical resorption level. The measurements obtained through each method were compared to the AL using the intraclass correlation coefficient (ICC) with the limits of agreement calculated with Bland and Altman analysis. The measurements were classified as acceptable (+/-1 mm from the AL) or not (>1 mm shorter or longer), and the McNemar test was employed for method comparison. Differences, limits of agreement and ICCs for each method were respectively EAL = -0.29; -1.02 to 0.44; 0.990; T + RAD = 0.17; -2.18 to 2.51; 0.929; RAD = 0.50; -3.41 to 4.41; 0.818; RDIG = 0.95; -3.76 to 5.65; 0.700; and T = -0.48; -5.59 to 4.64; 0.499. The most accurate and acceptable method was the EAL, followed by the T + RAD. : The EAL method performed best for root canal length determination in primary teeth.

Comparative analysis of the electronic and radiographic determination of root canal length of primary molars– an ex vivo study

Aim: ´To evaluate comparatively the radiographic and electronic root canal length determination in primary molars. Methods: 128 canals from 66 primary molars were selected. The root of each tooth was cut open on the occlusal face, and the real tooth length (RTL) was measured and the gold standard working length (WL) was determined by subtracting 1 mm from this measurement. The teeth were then placed in a plastic receptacle holding alginate and saline for the electronic determination of the root length using a Root ZX apex locator. The radiographic determination of the WL was obtained by subtracting 1 mm from the measurement highest cusp to the root apex appearing in the radiography. The data were analyzed statistically by the Chi-square test at a 5% significance level. Results: There was statistically significant difference (p<0.05) between each tested method and the gold standard. The Root ZX apex locator and the radiographic method presented satisfactory results in 75.78% and 54.68% of the cases, respectively. Conclusions: The Root ZX apex locator is a reliable method to determine the WL of primary teeth, since it showed greater accuracy than the radiographic method.

Accuracy of root canal length determination with the impedance ratio method

To provide insight into the principles of operation of electronic apex locators, determine optimal measuring parameters of the impedance ratio method, and to evaluate its accuracy. Electrical impedance was measured ex vivo on 14 extracted human teeth using a QuadTech 1920 precision impedance analyzer. A file electrode was inserted into the root canal; the second electrode was placed in the saline solution surrounding the tooth. Measurements were performed in a frequency range from 20 Hz to 1 MHz, and repeated with different distances of the file tip from the major apical foramen. The measured impedances were analysed as a function of distance of the file tip to the major apical foramen. Parameters (e.g. measurement frequencies, impedance ratio value) that would result in optimal working length determination were evaluated. The optimal determination of the major apical foramen position was obtained at frequencies of 5 kHz and 0.5 kHz, 10 kHz and 0.5 kHz, and 5 kHz and 1 kHz, for the impedance ratios 0.73 (95% CI: -0.33 to 1.74 mm), 0.66 (95% CI: -0.34 to 1.81 mm) and 0.79 (95% CI: -0.33 to 1.58 mm) respectively. The limit of +/-0.5 mm was attained in 86% of all measurements. Standard deviations decreased as the average measured distance approached and extended beyond the major apical foramen. With the obtained optimal measuring parameters, the impedance ratio method determined position of the major foramen within +/-0.5 mm. Accuracy varied depending on the set of frequencies used for evaluation as well as on the selected impedance ratio.

Ex vivo evaluation of the accuracy of two electronic apex locators during root canal length determination in primary teeth

To evaluate ex vivo the accuracy of two electronic apex locators during root canal length determination in primary incisor and molar teeth with different stages of physiological root resorption. One calibrated examiner determined the root canal length in 17 primary incisors and 16 primary molars (total of 57 root canals) with different stages of root resorption based on the actual canal length and using two electronic apex locators. Root canal length was measured both visually, with the placement of a K-file 1 mm short of the apical foramen or the apical resorption bevel, and electronically using two electronic apex locators (Root ZX II--J. Morita Corp. and Mini Apex Locator--SybronEndo) according to the manufacturers' instructions. Data were analysed statistically using the intraclass correlation (ICC) test. Comparison of the actual root canal length and the electronic root canal length measurements revealed high correlation (ICC = 0.99), regardless of the tooth type (single-rooted and multi-rooted teeth) or the presence/absence of physiological root resorption. Root ZX II and Mini Apex Locator proved useful and accurate for apex foramen location during root canal length measurement in primary incisors and molars.

Accuracy of two different apex locators in primary teeth with and without root resorption

The objective of this study was to assess the accuracy of two frequency apex locators, Root ZX (Morita, Kyoto, Japan) and Endex (Osada, Tokyo, Japan) in primary teeth with and without root resorption in vitro. For this study, 90 sound extracted primary teeth (60 molars and 30 incisors; 93 roots with visible resorption and 51 roots without) were selected. A total of 144 root canals were included. After access preparation, root canal lengths were measured visually. The teeth were embedded in an alginate model developed specifically for testing apex locators. Electronic length was determined with two different frequency apex locators, Root ZX (Morita, Kyoto, Japan) and Endex (Osada, Tokyo, Japan). Statistical evaluation was performed using Mann-Whitney U and Wilcoxon W tests (p < 0.05). Results revealed that both apex locator devices did not show similar values to visual length measurements with statistically significant differences in primary teeth with root resorption (p < 0.05). For the teeth without root resorption, Endex showed similar values to visual length measurements with no statistically significant differences (p > 0.05), but Root ZX values were different than visual length and the differences were statistically significant (p < 0.05). There were no significant differences between the two apex locators considering the presence of root resorption. The two frequency apex locators can be recommended for use in root canal therapy for primary teeth with and without root resorption, only if electrical determination of root canal length is supported with other diagnostic measures.

Introducing Radio-Opaque Radio-Lucent Graduated Root Canal Length Indicating Cones (GRCLIC) in Endodontics

Radio Opaque-Radiolucent Graduated Root-Canal Length Indicating Cone (GRCLIC) is a new innovative device being introduced for the first time in endodontics literature. GRCLIC can present more accurate measurement of the root canal length in conventional radiographs in endodontic and root canal treatment. Like many other dental and medical specialties, endodontics has evolved and changed over the years. The changes that have occurred in the past 10 years, however, have been of great magnitude and profundity. The microscope, ultrasonic units with specially configured tips, superbly accurate microchip computerized apex locators, flexible nickel-titanium files in rotary engines, and greater emphasis on microscopic endodontic surgery have totally changed the way endodontics and endodontic surgery are practiced. Every part of endodontic treatment is controlled by a measurement of the instrument's penetration depth into the canal, while the length is typically determined in millimeters. In this research, GRCLIC was used to enhance the more accurate root canal length determination. GRCLIC was made simply using a thin plastic or optic fiber graduated millimeter-wise with a heavy metal salt. The idea behind the GRCLIC technique was to present a new methodology which is actually a pre-exposure insertion of a simple graduated flexible ruler into the tooth canal instead of classic measurement methods. The main proved advantage of GRCLIC is decreasing mal-measurements which usually lead to treatment failures. GRCLIC enhances the success of endodontics treatment practices.

Influence of pulp vitality on length determination by using the elements diagnostic unit and apex locator

The aim of this study was to compare the influence of the pulp condition (vital or necrotic) on the determination of the root canal length by using a fourth generation electronic apex locator (EAL). The Elements Diagnostic Unit and Apex Locator was used to measure 143 teeth, totaling 294 canals with different conditions (236 necrotic and 58 vital pulp), for root length. After assessing the root canal and ascertaining the tooth length by using the EAL, the position of the file was confirmed by radiograph. The distance between the file tip and the root end was measured radiographically and was compared with the electronic measurement. Under clinical conditions within an acceptable range lower than 0.5 mm, the concordance between the 2 measurements was 96.6%. This new EAL showed no significant difference (P < or = .05) on accuracy of root canal length determination between vital cases (94.8%) and necrotic cases (97%). This device proved to be reliable regardless of the pulpal vitality.

Influence of Embedding Media on the Assessment of Electronic Apex Locators

Third-generation electronic apex locators for root canal length determination are very reliable and are not subject to interference from the contents of the canals. This study compared the effectiveness of different embedding media for in vitro assessment of electronic apex locators. The tooth lengths of 30 extracted human mandibular central incisors were measured by introducing a size 15 K-file fitted with a silicone stop into the canal until its tip appeared through the apical foramen; the distance between the tip and stop was measured. The teeth were placed in cylindrical polyethylene tubes filled with different embedding media (1% agar, gelatin, alginate, saline, and flower sponge soaked in saline), and electronic reading was performed with the Root ZX device. Data were statistically assessed by the analysis of variance (ANOVA) and Tukey tests at a significance level of 5%. Despite the lack of statistically significant difference among the media, the flower sponge was the only medium in which the file surpassed the apex in some measurements.

Accuracy of electronic apex locators in comparison to actual length—an in vivo study

The measurement precision of four electronic apex locators (Root ZX, Morita, Tokyo, Japan; Endy, Loser, Leverkusen, Germany; Justy II, Hager-Werken, Duisburg, Germany; Endox Lysis, Milan, Italy) was examined in the present in vivo study. The root canal length of 40 single-rooted and multi-rooted teeth was determined with the four devices prior to tooth extraction. To determine the actual root canal length, the apical third was longitudinally sectioned, the root canal instrument was positioned and the apex was examined using a microscope. The average measurement deviation (+/-SD) in relation to the apical constriction was 0.3 mm (+/-0.6) for the Root ZX, 0.7 mm (+/-1.0) for the Endy, 0.2 mm (+/-0.7) for the Justy II and 1.3 mm (+/-1.7) for the Endox. The limit of +/-0.5 mm from the apical constriction was attained by the Root ZX in 78%, by the Endy in 67%, by the Justy II in 80% and by Endox in 31% of all measurements. The latest generation of apex locaters provide the clinician with an accurate and useful adjunct for the determination of root canal length.

Root canal treatment performed by Flemish dentists. Part 1. Cleaning and shaping.

To gather information on root canal treatment carried out by dentists working in Flanders (Belgium). A questionnaire was handed to 312 dentists attending peer review sessions organized by the Flemish Universities. Basic information (age, gender, year of graduation, practice profile) and information on various issues relating to the cleaning and shaping of root canals was collected. A total of 310 questionnaires were returned. The majority (85.7%) of respondents categorized themselves as general practitioners; 25.7% mentioned a clinical interest or speciality in practice. Most practitioners (64.5%) did not use rubber dam routinely during root canal treatment and performed treatment over two visits irrespective of the number of root canals. The majority of respondents (82.4%) used sodium hypochlorite as an irrigant, but 10.6% did not know the concentration they used; EDTA was used by 61.6%. The vast majority exposed a radiograph with an instrument of known length in situ to gauge the working length; only 3.6% relied on tactile sense; electronic root canal length determination was seldom used. Amongst the root canal instruments, K-files were used solely or in combination with other instruments by 60.3% of the respondents, reamers were used solely or in combination with other instruments by 55.4%. The stepback technique was used by 31.2% of the participants, a combination of stepdown and stepback by 26.4%, a reaming technique by 26.1% and the step-down technique by 14.7%. The majority were familiar with mechanical root canal Instruments. Almost half of the practitioners believed their preparation technique could be improved: only 1.3% felt that their procedures were poor. The results of this study indicate that the theoretical knowledge of dentists working in Flanders is good. However, the use of rubber dam remained low, half believed their preparation technique could be improved.

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.

An evaluation of the Endometric Probe in root canal length estimation.

Summary. The purpose of this study was to evaluate the effectiveness of the Endometric Probe in the determination of root canal length in vitro. Using periapical radiographs, the lengths of root canals in 36 extracted teeth were assessed with the aid of a K‐file and an Endometric Probe. Both instruments were sealed, in turn, within each tooth some distance short of the true canal length. The distance between the tip of the instrument and a distance 1 mm short of the actual apex of the tooth was estimated from the radiographs. This distance was then added to the known length of the instrument in the canal to give an estimated canal length. Finally, the true length of each canal was determined by direct measurement using a reproducible method. The differences between the true and estimated canal lengths were then calculated and correlated with the type of instrument used. The results showed that, under the test conditions, the Endometric Probe was more reliable for root canal length estimation than the K‐file.