Root Canal Length Measurement Research Articles

A smart rotary technique versus conventional pulpectomy for primary teeth: A randomized controlled clinical study.

BackgroundTechniques with adequate accuracy of working length determination along with shorter duration of treatment in pulpectomy procedure seems to be essential in pediatric dentistry. The aim of the present study was to evaluate the accuracy of root canal length measurement with Root ZX II apex locator and rotary system in pulpectomy of primary teeth.Material and MethodsIn this randomized control clinical trial complete pulpectomy was performed on 80 mandibular primary molars in 80, 4-6-year-old children. The study population was randomly divided into case and control groups. In control group conventional pulpectomy was performed and in the case group working length was determined by electronic apex locator Root ZXII and instrumented with Mtwo rotary files. Statistical evaluation was performed using Mann-Whitney and Chi-Square tests (P<0.05).ResultsThere were no significant differences between electronic apex locator Root ZXII and conventional method in accuracy of root canal length determination. However significantly less time was needed for instrumenting with rotary files (P=0.000).ConclusionsConsidering the comparable results in accuracy of root canal length determination and the considerably shorter instrumentation time in Root ZXII apex locator and rotary system, it may be suggested for pulpectomy in primary molar teeth. Key words:Rotary technique, conventional technique, pulpectomy, primary teeth.

Influence of the instrument used for cervical preflaring on the precision of 2 Eletronic Apex Locators

ABSTRACT Objective: This study was aimed at evaluating the influence of cervical preflaring using LA-Axxes No. 1 bur (SybronEndo, Glendora, USA) or S1 and SX ProTaper files (Dentsply Maillefer, Ballaigues, Switzerland) on the accuracy of the Electronic Apex Locators (EALs): Root ZX mini (J. Morita Corporation, Tokyo, Japan), and Joypex 5 (Denjoy, Changsha, China). Methods: Thirty mandibular incisors were accessed, and the root canal length (RCL) was determined with a K-file #15, with the aid of a stereo microscope. Afterwards, the specimens were divided into 2 groups (n = 15) referring to the cervical preflaring with LA-Axxess or ProTaper files. The teeth were embedded in alginate and the RCL was determined by the EALs before and after preflaring. Data were classified into: accurate, if the difference in RCL measurement were ≤0.05 mm; and inaccurate, if the difference were &gt;0.5 mm or beyond the RCL. Results: McNemar's test (α&lt;0.05) was used to detect differences in the accuracy of the EALs before and after each preflaring with different instruments, and to detect difference in accuracy among devices. No differences were found concerning the accuracy of the EALs (P &gt; 0.05) after the cervical preflaring, regardless of the used instrument. Conclusion: The preflaring procedure increased the number of accurate measurements for both EALs, with statistical difference for Joypex 5 when the preflaring was performed with LA-Axxess. However, after the cervical preflaring, the EALs showed similar accuracy, regardless of the used instrument.

The Use of Micro–Computed Tomography to Determine the Accuracy of 2 Electronic Apex Locators and Anatomic Variations Affecting Their Precision

IntroductionThe aim of this study was to compare the accuracy of 2 electronic apex locators (EALs), Apex ID (SybronEndo, Glendora, CA) and Root ZX (J. Morita, Tokyo, Japan), by means of micro–computed tomographic (micro-CT) imaging and to determine anatomic variations that may affect their accuracy. MethodsThe root canal length (RCL) and working length (WL) of 33 single-rooted premolars were measured using a visual method, 3-dimensional micro-CT reconstructions, and 2 different EALs. Two different measurements were recorded for each EAL: at the “APEX/0.0” mark and at the “0.5” mark. The WL was determined using 2 different methods: method 1: at the “0.5 mark” of the apex locator and method 2: subtracting 0.5 mm from the “APEX/0.0” mark. The precision of measurements was compared with those recorded by micro-CT imaging. Apical foramen (AF) position and diameter, apical constriction (AC) diameter, distance between the AC and the AF, and the presence/absence of accessory canals were recorded from the micro-CT scans, and their correlation to the accuracy of EALs was determined. ResultsThere was no statistically significant difference in the RCL measurements by any of the different methods. There was a statistically significant difference in the WL recorded by micro-CT imaging compared with those by the visual method and at the “APEX/0.0 mark” − 0.5 mm (P = .031). There was no difference in the measurements acquired by any of the EALs. The “APEX/0.0 mark” − 0.5 mm was less accurate than the “0.5” mark. However, the results were not statistically significant (P > .05). The position of the AF and the AC–AF distance affected the accuracy of the RCL (P = .003) and the “0.5” mark (P = .013). ConclusionsRoot ZX and Apex ID are equally precise in determining the RCL and WL. The “0.5” mark can be used to determine the WL with high precision. Some anatomic variations may influence the accuracy of EALs.

Effect of root canal preparation on electronic measurement of root canal length

Effect of root canal preparation on electronic measurement of root canal length

A comparative study of the conventional and digital intraoral radiography methods for root canal length measurement

Objective: Measurement of root canal length is one of the most important stages of endodentic treatment, and any error at this stage can lead to the failure. This study aimed to compare conventional and digital intraoral radiography in measurement of root canal length. Material and Methods: In this study, 35 single-canal maxillary teeth were collected. Access cavities were prepared. An endodontic number 10#K- file was introduced into the canal, until the tip was visible at the apical foramen and the actual canal length (gold standard) was determined. After acquisition conventional radiographs using E-Ektaspeed and F-Insight film (Eastman-Kodak Co. Rochester, NY, USA) and digital radiographs using Photostimulable Phosphor Plates(PSP) (Soredex, Helsinki, Finland) and Charge Coupled Devices (CCD)(RVG, Trophy,NY,USA). they were examined separately with a two-week interval by two oral and maxillofacial radiologists. The data were analyzed with ANOVA and Tukey’s tests using SPSS-19 software (SPSS Inc., Chicago, IL, USA). Result: No statistically significant difference was observed between different radiographies, and different observers (P &gt; 0.05). Nevertheless, in comparison with the gold standard, in all cases, the F-speed conventional radiography and the digital CCD radiography showed the highest and the lowest accuracy, respectively. Also, the PSP and the E-speed conventional radiography were in the second and third order of accuracy, respectively. Conclusion: The use of digital radiography does not improve the accuracy of the root canal length measurement,but the digital technique has advantages,such as the reduced patient exposure ,eliminating the time consuming processing stages, and producing fast images.

Clinical evaluation of apex locator and radiography in primary teeth

The aim of this in vivo study was to evaluate the accuracy and reliability of electronic apex locater and radiographic determination of root canal length in primary teeth. A total of 32 human primary molar teeth (96 roots) were selected. After endodontic access preparation, root canals were irrigated with physiological saline solution. The access cavities were dried with cotton pellets and, the roots were dried with paper points before performing the electronic measurement. The root canal length measurements were first taken with an apex locater (EndoMaster), and then, a size ♯ 15 K-file was inserted into the root canal, and radiography was taken to determine the working length measurements. The measurement data were recorded and compared by one-way anova and Kruskal-Wallis tests. P < 0.05 was accepted for the significance. The mean values for radiography were 13.23 ± 1.92 mm and for EndoMaster were 13.08 ± 1.77 mm. The accuracy of EndoMaster was 80.2% in correct measurements ±1 mm (P < 0.001). The electronic apex locators could be useful in determining working length and thereby decreasing the need for radiographs and exposure to ionizing radiation in pediatric dental patients.

Accuracy of electronic apex locators in primary teeth: a meta-analysis.

To conduct a meta-analysis on the accuracy of electronic apex locators (EALs) in determining working length in human primary teeth. An electronic literature search was conducted using a combination of the terms 'primary teeth', 'root canal length' and 'electronic apex locators'. Additional eligible articles were identified using a manual search. The full texts of identified articles were screened according to inclusion criteria. Overall, 19 studies met the inclusion criteria and were subjected to further data extraction. Meta-analysis of studies that reported mean lengths and difference in mean lengths between EAL and actual root canal length (ARCL) revealed a significant difference (P=0.015) between the two readings whilst those studies that evaluated intraclass correlation (ICC) suggested a high correlation (P<0.0001) between the EAL and ARCL readings. A subgroup analysis revealed that the presence of root resorption did not affect the accuracy of EALs (P=0.567). Electronic apex locators offer an acceptable level of accuracy in the measurement of root canal length in primary teeth.

Determination of H-file sizes being more suitable for measuring of working length in immature teeth using an EAL

Successful root canal treatments of immature permanent teeth require data on the exact working length (W.L.) for the preparation of root canal in the clinic. The author and colleagues have previously reported that root canal length of an immature tooth can be measured using an electronic apex locator (EAL; Apit 11®, Osada Electric Co., Ltd., Tokyo, Japan) in in vitro experiments. This study aimed to find the sizes of H-files that are more suitable for root canal length measurements of immature teeth using Apit 11®. Extracted human immature permanent teeth were prepared to have accesses to their pulp cavities, and the root canal length of each tooth was measured physically and electronically using H-files, rular and Apit 11® in the in vitro experimental system. Six types of file diameters that are generally utilised in the clinic were used to take measurements in order to observe the relationship between the position of the file tip and the meter-indicated area. The results suggest that, of the H-files of sizes No. 10 to No. 70, No. 15 is probably the most reliable to locate the apical foramen when it is used with Apit 11®.

Cone-beam Computed Tomographic Scans in Comparison with Periapical Radiographs for Root Canal Length Measurement: An In Situ Study

IntroductionThe primary aim of this study was to compare the precision of root canal length determination on cone-beam computed tomographic (CBCT) scans and periapical radiographs (PAs) with the actual root canal length. The secondary aim was to examine the influence of tooth type on root canal length measurements as assessed on CBCT scans and PAs. MethodsIn total, 40 root canals of 33 teeth (molars, premolars, canines, and incisors) out of 5 dentate maxillas of human cadavers were included. Root canal length measurement was performed by a consensus panel (2 examiners) on CBCT scans (3D Accuitomo 170; J Morita, Kyoto, Japan) and digital PAs. After straight-line access opening, a #15 file was fixated in every root canal at the length measured on CBCT scans. All teeth were extracted, and the root canal containing the file was uncovered. Measurements made on images taken with a digital camera (AxioCam; Carl Zeiss, Sliedrecht, The Netherlands) linked to a stereozoom microscope (Stemi SV6, Carl Zeiss) were used as the actual root canal length. ResultsWhen all roots were examined together, it was not clear which method is better for all types of teeth. For root canals of anterior teeth, there was no significant difference between the 2 methods. For root canals of posterior teeth, CBCT images gave results significantly closer to the actual root canal length in comparison with PAs (t value = −1.96; critical value is 1.74 with a significance level of 0.05). ConclusionsRoot canal length measurements of posterior maxillary teeth were more accurate when assessed by CBCT images than PAs.

Comparison of Two Electronic Root Canal Length Measurement Devices: The Differences between Ratio Two Impedance Frequencies and Multi Frequencies

Accuracy electronic root canal length measurement devices were important for root canal treatment. Aim: To evaluate and compare accuracy of the two electronic root canal length measurement devices; two frequencies impedance ratio and multi frequencies. Methods: Forty anterior teeth were sectioned on their cervical area. All samples were measured root canal length by radiographic. On the second phase, all the samples were measured by two frequencies impedance ratio and multi frequencies electronic devices. In the final phase, the teeth were split vertically and actual lengths were measured. All measurement by radiographic and electronic method was subtracted with actual length. Statistical analysis was performed using Chi-square and the Kolmogorov-Smirnov test. Results: Accuracy of the two frequencies impedance ratio 50% and multi frequencies 47.5%. No statistical significance between two frequencies impedance ratio and multi frequencies. Conclusions: There is no difference between ratio two impedance frequencies and multi frequencies.

Influence of Apical Periodontitis on the Accuracy of 3 Electronic Root Canal Length Measurement Devices: An In Vivo Study

IntroductionThe aim of this in vivo study was to evaluate the influence of apical periodontitis (AP) on the accuracy of Dentaport ZX (J Morita, Kyoto, Japan), Raypex 5 (VDW, Munich, Germany), and i-Root (S-Denti, Seoul, Korea) electronic root canal length measurement devices (ERCLMDs). MethodsThirty-two single-rooted teeth scheduled for extraction, consisting of 16 teeth with AP and 16 teeth with normal periapex (NP), were selected. The access cavity was prepared, and the coronal portion of the canal was flared. The electronic working length (EWL) was determined by each ERCLMD according to each manufacturer's instructions. Each tooth was extracted, and the actual working length (AWL) was determined by inserting a size 15 K-file until the tip could be seen at a position tangential to the major foramen and then 0.5 mm was subtracted from the measurement. The distance from the file tip (EWL) to the point 0.5 mm coronal to the major foramen (AWL) was calculated. Data were analyzed using the nonparametric Fisher exact test and the chi-square test. Statistical significance was set at P < .05. ResultsThe accuracies of Dentaport ZX, Raypex 5, and i-Root within ±0.5 mm in the AP group were 93.8%, 81.3%, and 75.0%; they were 93.3%, 86.7%, and 73.3% in the NP group, respectively. There were no significant differences between the accuracy of each device in the 2 groups (P > .05). Considering the 2 groups of AP and NP, there were no statistically significant differences in the accuracy of the ERCLMDs (P > .05). ConclusionsThe presence of AP did not influence the accuracy of ERCLMDs.

The Validity of Cone-beam Computed Tomography in Measuring Root Canal Length Using a Gold Standard

IntroductionThe distance between a coronal reference point and the major apical foramen is important for working length determination. The aim of this in vitro study was to determine the accuracy of root canal length measurements performed with cone-beam computed tomographic (CBCT) scans using a gold standard. MethodsA total of 162 teeth (198 root canals) in 16 dry human dentulous mandibles were scanned using a 3DX-Accuitomo CBCT scanner (Morita 3DX; J Morita Mfg Corp, Kyoto, Japan). The root canal length was measured with CBCT data. All teeth were extracted atraumatically and endodontically accessed; the root canal length was measured blindly using a #10 K-file (Dentsply Maillefer, Ballaigues, Switzerland) and served as the gold standard. ResultsThe mean absolute difference of the CBCT-based root canal length from the gold standard was 0.46 mm (95% confidence interval, 0.41–0.50 mm). Only in 9 of 198 (4.5%) roots did the difference between the CBCT-based root canal length and the gold standard exceed 1 mm. ConclusionsCBCT-based root canal length measurements are accurate and reliable when compared with a gold standard.

The use of cone beam computed tomography to predetermine root canal lengths in molar teeth: a comparison between two-dimensional and three-dimensional measurements

The aim of this study was to evaluate the accuracy of two-dimensional (2D) and three-dimensional (3D) root canal length measurements in molar teeth using cone beam computed tomography (CBCT). Root canal lengths of twenty molar teeth were measured with two different CBCT approaches. After adjusting the CBCT images, 2D measurements were performed within the sagittal plane between the apical foramen and the coronal reference (cusp). The 3D approach measured centrically in axial planes. A linear mixed model with random intercepts was fitted to compare differences between methods (2D and 3D). The correlation between CBCT measurements and the actual root canal length was evaluated using the Pearson correlation coefficient. Differences between 3D measurements and the actual root canal lengths were significantly smaller compared to the 2D approach (p < 0.001). Mean differences were 0.32 and 0.58 mm, respectively. A high correlation was found between the actual root canal length and 3D measurements (Pearson correlation coefficient = 0.97). Compared to the actual root canal length, 80 % of the 3D measurements were within the limits of ±0.5 mm. 3D measurements of root canals in molar teeth are more accurate than simple 2D measurements and show a high correlation to the actual lengths. In cases where a CBCT is already available, root canal lengths in molar teeth can be accurately predetermined using a standardized 3D approach.

Evaluation of an improved endodontic teaching model: do preclinical exercises have an influence on the technical quality of root canal treatments?

To investigate whether the preclinical application of an electronic root canal length measurement device (ERCLMD) leads to more accurate working length (WL) determinations in a preclinical endodontic course and if this exercise effects the technical quality of root canal procedures when treatments are performed on patients for the first time. Root canal treatments performed by two consecutive groups of third year students (group 1: n = 39, group 2: n = 44) were compared in the preclinical course and when root canal treatments were performed on patients in the following term. Two different teaching models were applied in the preclinical endodontic course. WL in group 1 was determined with radiographs only. The teaching model applied in group 2 allowed the application of an ERCLMD. When treatments were performed on patients, both groups used the same technique to determine WL. It was first determined using an ERCLMD and verified radiographically. Master cone and root filling lengths were evaluated using radiographs, and comparisons between both groups were made using Fischer's exact test. Root fillings performed by students of group 2 were more often classified as acceptable. This observation was made in the preclinical endodontic course and when treatments were performed on patients. The application of an ERCLMD in combination with radiographs is more accurate to determine WL than radiographs alone. Students practiced the use of ERCLMDs with the new model and benefited from this experience when performing their first root canal treatments on patients.

Effect of solvents on the accuracy of the Mini Root ZX apex locator

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. 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. 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 ±0.5mm margin of error. 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.

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

Objective:The aim of this study was to evaluate, ex vivo, the precision of five electronic root canal length measurement devices (ERCLMDs) with different operating systems: the Root ZX, Mini Apex Locator, Propex II, iPex, and RomiApex A-15, and the possible influence of the positioning of the instrument tips short of the apical foramen.Material and Methods:Forty-two mandibular bicuspids had their real canal lengths (RL) previously determined. Electronic measurements were performed 1.0 mm short of the apical foramen (-1.0), followed by measurements at the apical foramen (0.0). The data resulting from the comparison of the ERCLMD measurements and the RL were evaluated by the Wilcoxon and Friedman tests at a significance level of 5%.Results:Considering the measurements performed at 0.0 and -1.0, the precision rates for the ERCLMDs were: 73.5% and 47.1% (Root ZX), 73.5% and 55.9% (Mini Apex Locator), 67.6% and 41.1% (Propex II), 61.7% and 44.1% (iPex), and 79.4% and 44.1% (RomiApex A-15), respectively, considering ±0.5 mm of tolerance. Regarding the mean discrepancies, no differences were observed at 0.0; however, in the measurements at -1.0, the iPex, a multi-frequency ERCLMD, had significantly more discrepant readings short of the apical foramen than the other devices, except for the Propex II, which had intermediate results. When the ERCLMDs measurements at -1.0 were compared with those at 0.0, the Propex II, iPex and RomiApex A-15 presented significantly higher discrepancies in their readings.Conclusions:Under the conditions of the present study, all the ERCLMDs provided acceptable measurements at the 0.0 position. However, at the -1.0 position, the ERCLMDs had a lower precision, with statistically significant differences for the Propex II, iPex, and RomiApex A-15.

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.

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

<i>In Vivo</i>accuracy of three electronic root canal length measurement devices: Dentaport ZX, Raypex 5 and ProPex II

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.

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

To compare in vivo three different electronic root canal length measurement devices: Dentaport ZX, Raypex 5 and ProPex II. Thirty single-rooted permanent teeth scheduled for extraction because of periodontal disease were selected from 10 adult patients (ranging from 45 to 67 years) and divided into three groups of 10 teeth. Before the extraction, an access cavity was prepared and the crown was adjusted to establish a stable reference point for all measurements. The working length in Group 1 was determined using the Dentaport ZX apex locator. A K-file with the largest diameter that could reach the last green bar on the screen was stabilized in the canal using a dual-curable flow resin composite. The same procedure was used for the Raypex 5 (the file reached the last yellow bar) and Propex II (0.0 orange bar) apex locators. The teeth were then extracted and cleared. The distance between the tip of the file and the major foramen was then calculated for each tooth using digital photography according to Axiovision AC software (Carl Zeiss). Positive values were assigned when the file tip passed beyond the major foramen, negative values when the tip was short of the foramen and zero value when the file tip and the foramen coincided. Statistical analysis was performed using the chi-squared test or Fisher's exact test (P ≤ 0.05). Dentaport ZX, Raypex 5 and ProPex ΙΙ produced, respectively, 6, 2 and 4 out of 10 correct measurements, 0, 6 and 5 long measurements and 4, 2, and 1 short measurements. The differences between the three electronic root canal length measurement devices were not significant (P = 0.507). Under the in vivo conditions of this study, the three electronic root canal length measurement devices were not significantly different in terms of locating the major foramen.