Canal Length Determination Research Articles

Coronal preflaring’s influence on the accuracy of root canal length determination by electronic apex locators

Coronal preflaring’s influence on the accuracy of root canal length determination by electronic apex locators

The usefulness of ultrasonography as a dynamic measurement system for visualizing root canal working length: an in vivo study

ObjectiveAlthough apex locators are generally effective tools for determining root canal working length, they may produce inaccurate results in some cases. The present study aimed to evaluate the efficacy of ultrasonography as an alternative method for measuring root canal length.Materials and methodsForty-seven anterior teeth with apical lesions were selected for the study. Initially, an electronic apex locator was used to measure the working length. Subsequently, ultrasonography was employed to visualize the root apex and determine the working length. During ultrasound imaging, a K-file No. 15 was inserted into the root canal until its tip was visible on the ultrasound monitor. Measurements obtained from both methods were compared using an independent sample t-test. Correlations were assessed with the Pearson correlation coefficient, and agreement was determined using the Bland‒Altman plot.ResultsThe mean working canal length was 19.9 mm for the apex locator and 20.6 mm for the ultrasonography-guided method. No significant differences were observed between the data obtained using the apex locator method and the data obtained using the ultrasonography guidance method. Furthermore, a high level of agreement was identified between the two techniques.ConclusionUltrasonography can be used to visualize the apex effectively and determine canal length, especially when canal length determination is uncertain for various reasons.

An Ex-Vivo Study Comparing the Accuracy of the E-Connect S+ and Morita Tri Auto ZX2+ Endodontic Handpieces in Root Canal Length Determination

IntroductionThis ex vivo study evaluated the accuracy of the Electronic Apex Locator (EAL) and Automatic Apical Stop (AAS) functions of the E-Connect S+ and Morita Tri Auto ZX2+ cordless apex locators in determining patency length. MethodsSixty-four human teeth with a single root were randomly allocated into E-connect or Morita groups (n = 32). The canals were accessed and preflared, after which a size 15 K-file was inserted into the canal to the major foramen and recorded as the actual length (AL). Matched measurements were taken using the AAS and EAL functions and visually confirmed with confocal microscopy. The variance between canal length (mm), the persons correlation (ρ) between function and AL, and the accuracy (%) of the canal length relative to the AL (Δmm) between devices and functions were assessed. ResultsRegardless of device or function, all measurements were within 1±Δmm and correlated strongly (ρ > 0.97) with the AL. When considering a more stringent clinically acceptable range of 0.5±Δmm from the AL, all devices and functions demonstrated similar accuracy levels (84%–94%). However, at lower tolerance ranges, the E-connect device with the EAL function exhibited the highest accuracy. On average, all devices and functions stopped short of the AL (mean Δmm>0). ConclusionThe E-Connect S+ and Morita Tri Auto ZX2+ apex locators provided reliable accuracy in determining the position of the major foramen. These findings demonstrate a high level of reproducibility in canal length measurements using both cordless endodontic handpieces, regardless of whether the EAL or AAS functions were employed.

Evaluation of The Accuracy of Two Apex Locators For Determining The Working Length of Endodontically Retreated Curved Mesial Roots of Maxillary Molar Teeth : An Ex Vivo Study

Objective: To evaluate the accuracy of PROPEX PİXİ (Dentsply Sirona, Ballaigues, Switzerland) and Apex ID (Sybron Endo, Orange, CA, USA) in determining the working lengths of curved mesial roots of upper molars during the retreatment procedure. Method: Twenty curved mesial roots of upper molar teeth were selected. Canals were shaped with ProTaper Next instruments (Dentsply Sirona) up to X3. The canal lengths were determined with a microscope (Carl Zeiss GmbH, Oberkochen, Germany) at 2,5X magnification (DM) and then also detected electronically (EM1P and EM1A) with PROPEX PİXİ (Dentsply Sirona) and Apex ID (Sybron Endo) in an alginate model. Specimens were then obturated using a size X3 master gutta-percha cone and an epoxy resin-based root canal sealer. Seven days later, the coronal part of the filling was removed with a Gates Glidden drill size 3 and for the middle part Protaper Universal Retreatment File D2 used. Working lengths electronically were detected again by two different apex locaters (EM2P and EM2A). Data were analysed by using the Wilcoxon Signed Rank and Mann Whitney u test. The analyses were carried out with MedCalc Statistical Software. Results: No significant difference was found between direct measurements (DM) and electronic measurements before and during retreatment for PROPEX PİXİ (P=0.135) and Apex ID (P=0.232). Also there was no significant difference between two apex locaters before (P=0.108) and during retreatment (P=0.242) Conclusion: PROPEX PİXİ and Apex ID were considered accurate for the root canal length determination during retreatment procedure. Keywords: Apex locator, curved molar, retreatment, working lenght

Effects of CBCT acquisition protocol and additional superimposed computerized optical impressions on the accuracy of root canal length measurements: an ex vivo study.

The purpose of this investigation was to evaluate the accuracy of root canal length determination in dependence of CBCT acquisition protocol and evaluating the influence of additional superimposed computerized optical impressions. CBCT scans with low-dose (LD) and high-definition (HD) protocols and computerized optical impressions of thirty extracted human molars were acquired. The Sicat Endo software (Sicat, Bonn, Germany) was used for CBCT root canal length (RCL) measurements with (LD+, HD+) and without (LD-, HD-) a superimposed optical impression. To evaluate the accuracy, absolute differences between test groups and the actual root canal length (ARCL) were calculated and statistically analyzed using the Wilcoxon-Rank-Sum-Test. Absolute differences between the ARCL and the tested measurement methods varied significantly (p<0.05). Both, higher resolution and additionally superimposed computerized optical impression improved measurement accuracy. Mean differences compared to the ARCL were 0.26 mm (HD+), 0.34 mm (HD-), 0.43 (LD+) and 0.66mm (LD-). 93.4% of all measurements in the HD+ group were within the limits of ±0.5 mm. Both resolution and superimposition of additional computerized optical impressions have a significant influence on root canal length measurements using CBCT.

Comparative analysis of root canal length determination using cone-beam computerized tomography and apex locator

Introduction. Determining the length of the root canal is one of the key factors that can affect the outcome of endodontic therapy. Incorrectly determined working length results in underfilled or overfilled canal. The aim of this work was to verify the effectiveness of cone-beam computerized tomography (CBCT) and apex locators in determining working length of the root canal. Material and method. Endodontic procedure was performed according to established endodontic protocol on 98 teeth. Teeth were divided into two groups: single-rooted and multi-rooted teeth. In both groups, working length was measured with an apex locator (Woodpex III) and CBCT (Planmeca Viso). In multi-rooted teeth, the canals were classified according to their morphological position into the groups Lingvomesial (LM), Buccomesial (BM), Bucodistal (BD), Palatal (P) and Distal (D) canals. Root canal length was determined by a dentist using apex locator at the University of Banja Luka while CBCT analysis was performed by a radiology engineer at the 3DENT radiology center in Banja Luka. Results. CBCT odontometry had small deviations from apex locator odontometry. The mean value of the absolute difference between CBCT measurement and apex locator measurement was the smallest in the group of linguomesial canals (0.284 mm), and the largest in the group of distal canals of the lower molars (1.939 mm). Based on the results of the Mann-Whitney U test, it was concluded that there was no statistically significant difference (p &gt; 0.05) in measured length of the root canal between the two methods in all groups of roots of multi-rooted teeth as well as in the group of single-rooted teeth. Conclusion. CBCT odontometry is as reliable as apex locator odontometry.

DETERMINING THE WORKING LENGTH OF A ROOT CANAL USING INTRAORAL RADIOGRAPHY SEGMENTATION

Apexlocators are devices that determine the working length of the root canal. Measurement with the help of alternating currents of different frequencies in combination with the method of the ratio allows to achieve high accuracy in determining the location of the physiological tip of the root (over 80%). However, such devices cannot accurately visualize where a doctor's tool is. Using image processing algorithms, you can segment tooth root structures with high precision. Therefore, the combination of electronic determination of the root canal length (using apexlocator) with X-ray segmentation is relevant.

The Effect of Long Service Life on the Accuracy of Dentaport ZX Electronic Apex Locator.

Electronic apex locators are among the most acceptable instruments for determining root canal length. The present study aimed to evaluate the effect of long service life on the accuracy of the Dentaport Root ZX (DP ZX) electronic apex locator (EAL). In this study, fifty single-rooted freshly extracted human teeth were used. After determining the root canal length with a K-file and a dental operative microscope, the canals were measured with four separate DP ZX apex locators (two with more than 6 years of life service while two others had less than 6 years of life service). Data were analyzed by repeated ANOVA measurement. No significant difference was found between the EALs with different years of life services (P=0.62). All EALs could determine root canal length with high accuracy of more than 94%. Based on the results of this in vitro study, the long service life had no significant impact on the accuracy of DP ZX EALs in terms of root canal length determination.

Accuracy of Four Electronic Apex Locators During Root Canal Length Determination

Accuracy of Four Electronic Apex Locators During Root Canal Length Determination

Comparing the accuracy of cone-beam computed tomography and electronic apex locator for root canal length determination in primary teeth

Comparing the accuracy of cone-beam computed tomography and electronic apex locator for root canal length determination in primary teeth

A Micro–computed Tomographic Evaluation of the Accuracy of 3 Electronic Apex Locators in Curved Canals of Mandibular Molars

IntroductionThis study evaluated the accuracy of 3 electronic apex locators (EALs) (CanalPro [Coltene-Endo, Cuyahoga Falls, OH], Apex ID [SybronEndo, Glendora, CA], and Root ZX Mini [J Morita, Tokyo, Japan]) in curved mesial canals of extracted mandibular molars using micro–computed tomographic (micro-CT) scanning. MethodsThe root canal length and the actual working length of 58 canals were measured using the visual method and 3-dimensional micro-CT reconstructions. The measurements of the EALs at marks “APEX/0.0” and “0.5 mark” were recorded as the electronic root canal length and the electronic working length, respectively. The absolute mean values and the percentages of distribution of the electronic measurements were compared with the actual lengths of the canals. The presence of isthmuses, accessory canals, foramen position, and the distance between the apical constriction and the apical foramen were recorded from the micro-CT scans, and their correlation to the accuracy of the EALs was determined. ResultsAll electronic measurements showed high agreement with their respective gold standard, except the electronic root canal length of the Apex ID (P < .05). No difference in the percentage of precise measurements (within the ±0.5 mm) was found among the devices (χ2 and z tests, P > .05). Of the anatomic parameters evaluated, the presence of a lateral foramen negatively affected the 0.0 mark of the Apex ID (Wilcoxon test, P < .05). ConclusionsThe Root ZX Mini and CanalPro were precise for both root canal length and working length determination in mesial curved canals of mandibular molars, whereas the Apex ID was accurate for the working length when using the 0.5 mark.

Accuracy and consistency of electronic root canal length determination with electrically isolating rubber stoppers.

The aim of this study was to investigate the influence of an isolating silicone stopper on the measuring accuracy and display consistency of three electrometric apex locators. The length of the canal to the major foramen was determined electrometrically using an ISO size 10 file in 20 extracted teeth each with natural crowns (Group I), amalgam fillings (Group II) or base-metal crowns (Group III), The measurements were performed with isolating or conventional silicone stoppers using three different apex locators with a four-level scale consistency rating. The use of isolating stoppers resulted in a more consistent display than with conventional stoppers, independent of the presence or type of coronal restoration (P = 0.017). Across all coronal restorations, the position of the major foramen could be determined to within ± 0.5 mm without significant differences (P = 0.79) using conventional and isolating stoppers. The use of modified isolating stoppers provides a significant increase in display consistency.

Determination of the Root Canal Length of Teeth of Bantu Patients Attending the Teaching Hospital of Kinshasa University

Background: There is paucity of literature on the determination of the root canal length of Bantu subjects in dental professional practicing in Africa and Democratic Republic of Congo in particular. Aims: The aim of the present study was to determine the root canal length of teeth of Bantu patients extracts attending the Teaching Hospital of Kinshasa University. Methods and Material: Prospective cross-sectional study was carried out in the service of Conservative Dentistry. The patients suffering with pulpitis of permanent teeth which were selected for root canal treatment during the period of January 2014 to December 2016 were included. All patients whose main root canals were inaccessible, teeth carrying prosthesis, teeth with large coronal decay, teeth having periapical periodontitis, supernumerary teeth, wisdom and primary teeth were excluded. Results: The upper canines presented some significant longer canals compared to the lower canine (23.4 ± 2.3 mm and 21.6 ± 1.8 mm). Palatal canals of the first and second molar were respectively longer as compared to the superior teeth canals (21.5 ± 1 mm, 21.3 ± 2 mm). The distal canals of the first and second molar were the longest in the mandibular arch respectively measuring 20.7 ± 2.0 mm and 21.5 ± 1.7 mm. Conclusion: Data obtained from Bantu patients show slightly shorter roots compared to some European populations, but longer than some Asian populations.

Use of artificial primary teeth for endodontic laboratory research: experiments related to canal length determination

BackgroundDue to the scarcity of exfoliated/extracted human primary teeth with complete roots, artificial teeth were developed as an alternative to be used for educational and laboratory research purposes. This study aimed to assess the feasibility of using artificial primary teeth for conducting laboratory research through an experiment related to canal length determination, comparing artificial teeth with natural teeth.MethodsThirty anterior and 21 posterior artificial teeth, and the same number of natural primary teeth were selected. After preparing the access cavity, the root canal length was determined by two examiners twice using three different methods: radiography and two electronic apex locators. Then, the actual root canal length was measured by inserting a K-file up to the apical foramen (reference standard). Accuracy was calculated using Bland-Altman analysis and intraclass correlation coefficient (ICC). The inter- and intra-examiner reproducibility was also calculated using the ICC.ResultsThe methods using the electronic apex locators showed better accuracy in both artificial and natural teeth. Trends observed with artificial primary teeth were similar to those observed with natural teeth, except for the results in artificial anterior teeth.ConclusionsThe model of artificial teeth might be a good alternative for educational purposes; however, improvements are necessary to employ these teeth for research purposes when considering experiments for canal length determination.

A survey on working length determination of endodontic treatment

The purpose of this study is to evaluate the preferred method of root canal length determination and the apical limit for canal instrumentation among endodontic teachers of dental school. A questionnaire on the preferred method of root canal length determination and the apical limit for canal instrumentation was designed and distributed to endodontic teachers of various dental schools. The response rate was 90%. The most preferred method of root canal length determination was Electronic apex locator (EAL)(89%). The most favoured apical limit for canal instrumentation was 0.5 to 1.0 mm short of the radiographic apex(78%). The most preferred method of using EAL was that the working length is taken at 'APEX' mark and then distracted 0.5mm from that length.(41%). When there is no agreement between radiographic measurement and EAL measurement, 74% of respondents chose the length of EAL measurement. The majority of endodontic teachers from Korean dental schools preferred EAL to radiograph method in determining root canal length.

Comparison of electrical equivalent circuits of human tooth used for measuring the root canal length

An accurate determination of the root canal length, which is the most critical procedure in the endodontic treatment of a tooth, is commonly performed nowadays by electronic apex locators which are based on electrical impedance measurements. In this paper tooth impedances were measured in vitro on extracted tooth in alginate material using HP 4284A LCR meter and a specially designed stalk with a micrometer for precise file positioning. In order to develop a more accurate measurement procedure human tooth was modeled by electrical equivalent circuit. Four new equivalent circuits comprising of resistors, capacitors and constant-phase elements were proposed in this paper and compared with four previously suggested circuits. Elements of equivalent circuits were determined by complex nonlinear least squares fitting using LEVM software. Different quality factors were defined to describe the fit quality of a certain equivalent circuit at each file position. The overall fitting efficiency in the region of file positions of interest was calculated as well. A detailed discussion was given on equivalent circuit parameters that can be used to measure the root canal length. Upon these results the most appropriate equivalent circuit was selected and a new measurement procedure was proposed.

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.

Performance in vitro of apex locators in determining root length in primary molars

ABSTRACT Objective: The aim of the study was to evaluate performance of digital radiographic and two electronic apex locators, Propex II and Root ZX in root canal length determination in primary molars. Methods: 25 primary molars were divided into two groups, G1 without root resorption and G2 with root resorption. The exams were performed using all methods by two experienced examiners, with 1-week interval. The gold standard was determined by visual examination. The methods were statistically analyzed regarding the values of reproducibility and correlated with the gold standard by Pearson´s correlation coefficient. Results: The root canal length determination coincided with gold standard in 22.7% for Root ZX, 17.5% for Propex II and 12.5% for digital radiography. Correlation values were higher in G1, the Root ZX presented the highest values. In G2 the digital radiography showed the lowest correlation. In G1, the intra-examiner reproducibility values ranged from 0.925 to 0.523, and interexaminer 0.863 to 0.670. In G2, the values of intra-examiner reproducibility ranges from 0.864 to 0.097, and inter was 0.774 to 0.379. Conclusion: It was concluded that the methods performance varying according to examiner's experience. The Root ZX presented the highest reproducibility and accuracy.

An in vitro evaluation of the accuracy of four electronic apex locators using stainless-steel and nickel-titanium hand files.

ObjectivesThe purpose of this in vitro study was to evaluate the accuracy of working length (WL) determination of four electronic apex locators (EALs), namely, Root ZX (RZX), Elements diagnostic unit and apex locator (ELE), SybronEndo Mini Apex locator (MINI) and Propex pixi (PIXI) using Stainless steel (SS) and nickel-titanium (NiTi) hand files. The null hypothesis was that there was no difference between canal length determination by SS and NiTi files of 4 EALs.Materials and MethodsSixty extracted, single rooted human teeth were decoronated and the canal orifice flared. The actual length (AL) was assessed visually, and the teeth were embedded in an alginate model. The electronic length (EL) measurements were recorded with all four EALs using SS and NiTi files at '0.5' reading on display. The differences between the AL and EL were compared.ResultsThe results obtained with each EAL with SS and NiTi files were compared with AL. A paired sample t test showed that there was a statistical significant difference between EAL readings with SS and NiTi files for RZX and MINI (p < 0.05). The accuracy of RZX, ELE, MINI and PIXI within ± 0.5 mm of AL with SS/NiTi files were 93.3%/70%, 90%/91.7%, 95%/68.3%, and 83.3%/83.3%, respectively.ConclusionsThe results of this study indicate that Root ZX was statistically more accurate with NiTi files compared to SS files, while MINI was statistically more accurate with SS files compared to NiTi files. ELE and PIXI were not affected by the alloy type of the file used to determine WL.

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.