Working Length Determination Research Articles

Comparison of Working Length Determination Using Apex Locator and Conventional Radiography in Curved Canals-an In Vitro Study

Comparison of Working Length Determination Using Apex Locator and Conventional Radiography in Curved Canals-an In Vitro Study

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.

Assessment of the accuracy of a fifth generation apex locator (in vitro study)

Background: The use of electronic apex locators for working length determination eliminates many of the problems associated with the radiographic measurements (interference of anatomical structures, errors in projection such as elongation or shortening, and lack of three-dimensional representation). Its most important advantage over radiography is that it measures the length of the root canal to the apical constriction, not to the radiographic apex. The aim of this study was to assess the accuracy of a new fifth generation apex locator (Joypex 5) in recording the apical constriction and comparing it with a third generation apex locator (Root ZX) in vitro. Materials and method: Twenty four single-rooted sound human premolars, extracted for the purpose of orthodontic treatment and with fully-formed roots, were used in this study. Endodontic access cavity was prepared in each tooth and canal patency up to the apical foramen was checked with a #15 stainless steel K-file. No root canal preparation was performed. Root canal length measurement was done directly and electronically using two apex locators (Joypex 5 and Root ZX). Direct measurement of the root canal length was done by introducing a #15 K-file inside the root canal until its tip was just visible at the apical foramen, then removed from the root canal and its length was measured (in mm) and subtracted by 0.5 mm. For electronic measurement, the teeth were fixed in a sponge soaked in saline and the root canals were also filled with saline. The lip electrode was attached to the sponge and the apex locators were used according to the manufacturers' instructions. The file holder was clipped to the metal shaft of a #15 K-file and the file was then inserted inside the root canal and advanced until the display reading on the LCD of the apex locator was 0.5. The file was then removed from the root canal and its length was measured (in mm). The differences between the readings of each apex locator and the actual length of each canal were computed, and the results were analyzed statistically by paired t-test using SPSS Version 13. Results: The results of this study showed that the Joypex 5 apex locator showed a lower mean difference than the Root ZX apex locator as compared with the actual length, which was statistically significant (p<0.05). Concerning the accuracy of the two apex locators, Joypex 5 apex locator recorded the apical constriction exactly in 67%, while the Root ZX apex locator in only 25%. Within ±0.5 mm from the actual length, the accuracy of the Joypex 5 and the Root ZX were 83% and 67%, respectively. Within ±1 mm from the actual length, the accuracy of the Joypex 5 and the Root ZX were 100% and 96%, respectively. Conclusion: The Joypex 5 apex locator which is a fifth generation apex locator was more accurate in recording the apical constriction as compared with the Root ZX apex locator which is a third generation apex locator.

Can active signals of cellphone interfere with electronic working length determination of a root canal in a dental clinic? An in vivo study.

Objective:To evaluate the interference of active cellphones during electronic working length (EWL) determination of a root canal.Materials and Methods:Thirty patients requiring root canal treatment in the anterior teeth or premolars having single canal and mature apices were selected for this study. Working length determination was done using no. 15 K-file. Electronic apex locators ProPex Pixi and Root ZX mini were used for working length determination. Cellphones iPhone 6s and Xolo Q3000 were evaluated for their interference. The experiment was conducted in a closed room (9 feet × 9 feet). Working length was measured with no cellphone in the room, iPhone 6s in a calling mode, Xolo Q3000 in a calling mode, and Xolo Q3000 and iPhone 6s simultaneously in a calling mode. Stability of the readings was also determined for every condition.Statistical Analysis:The data were statistically analyzed using one-way ANOVA and paired t-test at 0.05 level of significance.Results:Results were not statistically significant.Conclusion:Within the limitations of the present study, cellphones do not interfere with the EWL determination.

Do mobile phones cause interference on electronic apex locators? An in vitro study

Aim: The purpose of this study was to evaluate the interference of smart phone (Iphone 5s) during working length determination on electronic apex locators (Root ZX and NSK ipex II) function in vitro. Materials and Methods: Two EALs: Root ZX (J. Morita Co., Tustin, CA, U.S.A.) & NSK ipex II were tested for any interference with smart phone during working length determination. The effect of cellular phones on electronic working length (EWL) was determined under 2 experimental settings: 1) in a multispeciality set up with good signal strength 2) in a closed room with poor signal strength and Five conditions a) Control group - No mobile phone in the room b) In close contact with EAL in safe mode c) in close contact with EAL for 30 seconds d) Phone kept at a distance of 35 cm from EAL in safe mode e) Phone kept at a distance of 35 cm from EAL in calling mode for a duration of 30 seconds. The readingswas scored from 1 to 3 and the data was subjected for statistical analysis. Results: Statistical significant difference was obtained when an intergroup comparison was made using two- way repeated analysis of variance. Conclusion: Electronic apex locators tested did not cause inhibition or interfere with mobile phones.

Evaluation of root canals filled with bioceramic sealer after retreatment with two different techniques

Purpose: To evaluate the remaining filling material (gutta-percha/EndoSequence bioceramic sealer) on root canal walls after retreatment using ProTaper universal retreatment (PTUR) system with and without chloroform solvent. Materials and methods: Thirty extracted human premolars with type I root canal system were used. After crown removal and working length determination, all root canals were prepared using nickel–titanium rotary ProTaper system and obturated using gutta-percha as a core filling material with EndoSequence bioceramic sealer. All roots were randomly divided into two equal main groups (n = 15) according to retreatment technique. Group I: filling materials was removed using PTUR system and chloroform as a solvent; while group II: filling materials was removed using PTUR system without solvent. Both groups were cleaved longitudinally and examined under scanning electron microscope to evaluate root canal filling remnants. Results: PTUR system with the aid of chloroform recorded highest values of score percentage of remaining filling material at all tested root canal levels. The values of score percentage of remaining filling materials were significantly lower at coronal level compared to other tested levels. Conclusion: Using chloroform during removal of root canal filling material using rotary instruments was associated with larger amount of residual root canal filling material compared to using rotary instruments only.

Comparison of Apical Transportation with the Use of Rotary System and Reciprocating Handpiece with Precurved Hand Files: An In Vitro Study.

Introduction:Success of root canal treatment depends on several factors; among which, maintaining the original canal path during mechanical preparation is extremely important. This in vitro study aimed to compare apical transportation using RaCe NiTi rotary system and precurved stainless steel (SS) hand files in a reciprocating handpiece. Methods and Materials:Mesiobuccal canals of 40 extracted human mandibular first and second molars with 20 to 45° curvatures and 3 to 7 mm curve radius were chosen for this study. After working length determination, the teeth were divided into two groups (n=20). Root canals were prepared with RaCe in group 1 and NSK handpiece and precurved SS hand files in group 2 up to #30 with 2% taper in both groups. Radiographs were taken of teeth before and after instrumentation from buccolingual and mesiodistal directions. The images were superimposed using Adobe Photoshop CS3 software. Degree of straightening and amount of apical transportation at 0, 0.5, 1, 2, 3, 4 and 5 mm levels short of the working length were determined using digital subtraction radiography. The student’s t test was used to compare the degree of straightening and Mann Whitney test was applied to compare apical transportation (millimeters) between the two groups. Results:No significant difference was noted between the two groups on buccolingual or mesiodistal views in degree of straightening and apical transportation on buccolingual view (P>0.05). However, on mesiodistal view, NSK reciprocating handpiece caused greater apical transportation at 0. 0.5 and 1 mm levels (P<0.05). Conclusion:The RaCe system and precurved SS files in reciprocating handpiece were highly similar in terms of degree of straightening and apical transportation. Thus, engine-driven NSK reciprocating handpiece can be used as an efficient adjunct for root canal preparation.

Comparative evaluation of effect of rotary and reciprocating single-file systems on pericervical dentin: A cone-beam computed tomography study.

Aim and Objective:The aim of this study is to evaluate and compare the effect of one shape, Neolix rotary single-file systems and WaveOne, Reciproc reciprocating single-file systems on pericervical dentin (PCD) using cone-beam computed tomography (CBCT).Materials and Methods:A total of 40 freshly extracted mandibular premolars were collected and divided into two groups, namely, Group A – Rotary: A1 – Neolix and A2 – OneShape and Group B – Reciprocating: B1 – WaveOne and B2 – Reciproc. Preoperative scans of each were taken followed by conventional access cavity preparation and working length determination with 10-k file. Instrumentation of the canal was done according to the respective file system, and postinstrumentation CBCT scans of teeth were obtained. 90 μm thick slices were obtained 4 mm apical and coronal to the cementoenamel junction. The PCD thickness was calculated as the shortest distance from the canal outline to the closest adjacent root surface, which was measured in four surfaces, i.e., facial, lingual, mesial, and distal for all the groups in the two obtained scans.Results:There was no significant difference found between rotary single-file systems and reciprocating single-file systems in their effect on PCD, but in Group B2, there was most significant loss of tooth structure in the mesial, lingual, and distal surface (P < 0.05).Conclusion:Reciproc single-file system removes more PCD as compared to other experimental groups, whereas Neolix single file system had the least effect on PCD.

A Comparative Evaluation of Accuracy of New-generation Electronic Apex Locator with Conventional Radiography to determine Working Length in Primary Teeth: An in vivo Study.

AimsThe purpose of this study was to evaluate the accuracy of a new-generation electronic apex locator (iPex) to determine working length in primary teeth with or without root resorption as compared with the conventional radiographic method.Materials and methodsA sample of 30 primary posterior teeth which are indicated for pulpectomy were selected for the study. After obtaining the informed consent from the parents, local anesthesia was administered. Access cavity was prepared with no.10 round bur. Initial exploration of the canals was done with no.10 K-file. Pulp was extirpated with a barbed broach followed by thorough irrigation of the canals with 0.9% saline. Initially, working length was obtained with iPex (new-generation by Nakanishi International) apex locator using no.10 K-file, which was then compared with conventional radiographic method (Ingle’s method).ResultsA total of 65 canals were available for the measurement. The data were analyzed using Statistical Analysis system and t-tests were carried out. There was no statistically significant difference found when using iPex apex locator for working length determination as compared with that of conventional radiographic method (p = 0.511).ConclusionWorking length determined by iPex apex locator is comparable with that of conventional radiographic method, hence, can be used as an alternative in determining the working length of primary teeth.How to cite this articleBhat KV, Shetty P, Anandakrishna L. A Comparative Evaluation of Accuracy of New-generation Electronic Apex Locator with Conventional Radiography to determine Working Length in Primary Teeth: An in vivo Study. Int J Clin Pediatr Dent 2017;10(1):34-36.

Modified Bisecting Angle Technique: A Novel Method to Eliminate Zygomatic Superimposition over the Apices of Maxillary Molars

Objectives: Intra oral radiographic imaging is the most widely used method for obtaining information about root canal anatomy and working length determination. Measuring exact working length is the most essential step for the success of root canal treatment. Bisecting angle technique (BAT) is the most widely used technique for this purpose. However, zygomatic superimposition over the apices of maxillary molars makes it difficult for the dentist to estimate exact working length. The present study made certain modifications in BAT to overcome these undiagnostic shadows. The aim of the study is to compare three techniques, namely paralleling cone technique (PCT), BAT and modified bisecting angle technique (MBAT) to prevent such superimposition over molar apices. Materials and Methods: A total of 53 patients requiring endodontic treatment for maxillary molars were included in the study. Three radiographs one with each PCT, BAT, MBAT were made. Each radiographic image was recorded acceptable or unacceptable based on the zygomatic superimposition. The data thus collected was subjected to statistical analysis using chi-square test. Results: The percentage of acceptability in MBAT was 56.6% (n = 30) when compared with BAT which was only 28.3% (n = 15) and PCT was 58.3% (n = 31) indicating statistically significant difference between BAT and MBAT. But no statistically significant difference was found between MBAT and PCT. Conclusion: In the present study, MBAT was found to be more accurate than BAT, and it was relatively as accurate as PCT in eliminating zygomatic superimposition over the apices of maxillary molars.

In-vitro comparison of four different working length determination techniques

Aim: The aim of this study was to compare four different working length determination techniques. Materials and methods: Fifty extracted single-canaled anterior teeth were decoronated. The root canals' working lengths were repetitively determined in five groups (n = 50 each) using regular radiographic film (group 1), digital radiographic image (group 2), cone-beam computed tomographic image (group 3), electronic apex locator (group 4) and direct measurement (group 5, control) by subtracting 0.5 mm from the length of # 15 k-file visible at the apical foramen. The collected data was statistically analyzed using both analysis of variance and least significant difference (LSD) comparisons at P value less than or equal to 0.05. Results: The one-way analysis of variance indicated a difference between the data of study groups (P = 0.011). The LSD comparisons revealed a longer working length (LSD, P ≤ 0.05) in groups 1 and 2 than groups 3 and 5 (control). On the other hand, No difference (LSD, P > 0.05) was detected between the working length in groups 3 and 4 in comparison with group 5 (control). Conclusion: The electronic apex locator and the cone-beam computed tomography are more accurate techniques to determine root canal's working length than the normal and the 2D digital radiographs.

Factors associated with postobturation pain following single-visit nonsurgical root canal treatment: A systematic review.

Reducing the pain after root canal therapy is a key aspect in endodontic practice. The present systematic review aimed to identify the factors that influence postobturation pain (POP) in patients receiving single-visit nonsurgical root canal treatment. A literature search was performed manually and in Pubmed (Medline) database to identify relevant articles. A data extraction form was constructed and data were collected from the identified articles. In total, 24 articles were identified for the systematic review, and factors associated with POP were tabulated. Specific preoperative factors (old age, sex, molar teeth, mandibular teeth, presence of preoperative pain, and absence of periapical radiolucency) and procedures (administration of prophylactic drug, bupivicaine anesthetic agent, radiograph or apex locator working length determination methods, instrumentation, irrigating system, laser, cold lateral compaction obturation technique, reducing the occlusion, and postoperative drugs) were associated with POP.

Accuracy of two different apex locators for working length determination during root canal retreatment of mandibular molars using two different retreatment files: An in vitro study

Aim: The aim of this study was to determine the accuracy of two different apex locators for measurement of working length during root canal retreatment of mandibular molars with two different file systems in an ex vivo study. Materials and Methods: Sample consisting of sixty extracted mandibular first molars was selected. Tooth length was measured with a file. Biomechanical preparation of the roots was done with Protaper files 1mm short of the tooth length. Canals were coated using AH Plus sealer and were obturated with gutta percha. Obturating material was removed after one week with two files i.e Protaper and Mtwo retreatment files. Tooth length was remeasured and recorded as the retreatment tooth length (RTL). Then electronic measurements were taken with Root ZX and Apex ID apex locator as suggested by the instrument display. These lengths were compared with RTL at 0.5 and 1 mm short of this distance. Results: For both canals, no significant difference was found between RTL and EAL measurements with Root ZX apex locator and protaper retreatment files. There was a significant difference between Apex ID apex locator with M2 retreatment files readings. Conclusion: Root ZX apex locator was more accurate as compared to Apex ID apex locator in determining the working length in teeth after removing the root canal obturating material using two different files.

Evaluation of Conventional Radiography and an Electronic Apex Locator in Determining the Working Length in C-shaped Canals.

Introduction:The purpose of this in vitro study was to compare the accuracy of working length determination using the apex locator versus conventional radiography in C-shaped canals. Methods and Materials:After confirming the actual C-shaped anatomy using cone-beam computed tomography (CBCT), 22 extracted C-shaped mandibular second molars were selected and decoronated at the cemento-enamel junction. The actual working length of these canals were determined by inserting a #15 K-file until the tip could be seen through the apical foramen and the working length was established by subtracting 0.5 mm from this length. The working length was also determined using conventional analog radiography and electronic apex locator (EAL) that were both compared with the actual working length. The data was statistically analyzed using paired t-test and marginal homogeneity test. Results:There was no significant differences between the working length obtained with apex locator and that achieved through conventional radiography in terms of measuring the mesiolingual and distal canals (P>0.05); while, significant differences were observed in measurements of the mesiobuccal canals (P=0.036). Within ±0.5 mm of tolerance margin there was no significant difference between EAL and conventional radiography. Conclusion:The apex locator was more accurate in determination of the working length of C-shaped canals compared with the conventional radiography.

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.

Comparison of the accuracy of conventional and digital radiography in root canal working length determination: An in vitro study

Background. Digital radiography has widespread use in endodontics. Determining a correct working length is vital for a proper endodontic therapy. The aim of this study was to compare the accuracy of conventional and digital radiographic techniques for root canal working length determination. Methods. After determining the real working lengths of 50 permanent maxillary central incisors (gold standard), the conventional (E- and F-speed films) and digital (CCD, PSP) images were obtained using the parallel technique. The mean registered working length of each modality was compared with the other and with the gold standard using one-way ANOVA at P<0.05. Results. No significant difference was found between the recorded working length values using the conventional and digital radiographic techniques (P=0.828). Conclusion. Within the limitations of this study, it was concluded that there was no difference between the measurement accuracy of CCD, PSP and conventional imaging techniques in root canal working length determination.

Endodontic Working Length Measurement Using Cone-beam Computed Tomographic Images Obtained at Different Voxel Sizes and Field of Views, Periapical Radiography, and Apex Locator: A Comparative Ex Vivo Study

IntroductionThe aim of this study was to evaluate the accuracy of working length determination by using an electronic apex locator, periapical radiography, and cone-beam computed tomographic (CBCT) imaging obtained at different voxel sizes and field of views (FOVs) in extracted human teeth. MethodsThirty extracted human mandibular premolar teeth were used. The electronic working length measurements were performed by using an electronic apex locator (Root ZX; J Morita Corp, Kyoto, Japan). Five different image sets were obtained as follows:(1) CBCT imaging: 40 × 40 mm FOV, 0.080 mm3 (FOV40);(2) CBCT imaging: 60 × 60 mm FOV, 0.125 mm3 (FOV60);(3) CBCT imaging: 80 × 80 mm FOV, 0.160 mm3 (FOV80);(4) CBCT imaging: 100 × 100 mm FOV, 0.250 mm3 (FOV100); and(5) periapical digital radiography. Direct measurements performed with an electronic digital caliper were considered as the gold standard and compared with the electronic apex locator, CBCT, and periapical image measurements. Data were analyzed using a 2-way analysis of variance test. Significance level was set at P < .05. ResultsThere was no significant difference between or within operators in intraoral radiographs (P > .05 and the Gage R&R value was <30%). There were significant differences between and within operators for CBCT images (P < .05 and Gage R&R value was >30%). There were significant differences in the methods in terms of mean differences from the gold standard (P < .05). ConclusionsThis study showed that available CBCT scans with different FOVs can be used for working length measurement.

An Invitro Evaluation of the Accuracy of Two Electronic Apex Locators to Determine Working Length in the Presence of Various Irrigants.

Cleaning and shaping of root canal system requires various irrigating solutions. The question is whether the presence of irrigation solution alters working length determination using apex locators. The purpose of this study was to compare the accuracy of Root ZX and i-Root apex locator for determining working length in the presence of different irrigating solution. Eighty extracted single rooted human teeth were used. The teeth were sectioned at Cemento Enamel Junction (CEJ) and actual canal length determined. Then, working length measurements were obtained using Root ZX and i-Root apex locator in the presence of irrigating solutions namely 0.9% saline, 3% of sodium hypochlorite (NaOCl), 2% chlorhexidine digluconate(CHX) and 17% Ethylene Diamine Tetra Acetic acid (EDTA). The measurements obtained with Root ZX and i-Root apex locator were compared with actual canal length and subjected to statistical analysis using Post Hoc Test Tukey's Method. This study revealed that both the tested Electronic apex locators (EAL) were able to measure the canal length in the presence of tested irrigating solutions. The presence of irrigating solutions of saline, NaOCl, chlorhexidine and EDTA in the root canal marginally influenced the accuracy of the Root ZX or i-Root (P < 0.36), but with no clinical significance. Root ZX and i-Root can be used safely to determine working length in the presence of various irrigants. The content of the root canal did not influence the accuracy while measuring working length using Electronic apex locators (EAL).

Performance of the Working Length Determination using Cone Beam Computed Tomography, Radiography and Electronic Apex Locator, in Comparisons to Actual Length

Background: Determination of the working length (WL) is important on the success of the endodontic treatment. There are several techniques used for the determination of endodontic WL, whereas new technologies may include clinical practice and, therefore, they should be investigated. Objectives: The goal of the cone beam computed tomography (CBCT) based investigation was to compare determination of the WL performance of the electronic apex locator (EAL), CBCT and digital radiography. Materials and Methods: Totally, 30 single rooted, freshly extracted permanent teeth were included. Root canal WL measurements were performed using actual length (AL), EAL, digital radiograph and CBCT. The percentages of ± 0.5 mm measures to the AL, among the experimental groups, were compared by using Chi-Squared and Fischer Exact tests. The statistical significance was determined at P < 0.05. Results: The CBCT was the most accurate method to evaluate the root canal WL, with accuracy of 70%. Accuracy for the apex locator and periapical radiograph were 40% and 30%, respectively. Conclusion: The CBCT may be safe to use in determining root canal WL. Because lower radiation dose, a pre-existing CBCT can be useful to detect the root canal WL more precisely.

Radiographic Practices &amp; The Use of Apex Locators In Endodontic Treatment In Mumbai – A Comparison of Perceptions Between Endodontists &amp; Other Dental Practitioners.

Aims and Objective: The aim of our study was to assess the attitudes of general practitioners, endodontic specialists & other specialists in and around Mumbai in relation to the use of electronic apex locator and the radiographic practices prevailing among them for root canal therapy. Materials and Methods: A cross-sectional contact survey was conducted including 400 dental professionals in and around Mumbai who performed endodontic procedures. A specially prepared format exclusively designed for recording all the required relevant general information and information related to working length determination method was used as a tool for data collection.Data was tabulated in excel sheet and analyzed using SPSS 22.0 software. Discussion and Conclusion: From the survey, it was observed that the Endodontists employed apex locators and RVG more frequently than their colleagues’ in general dental practice and this finding was statistically significant. It was also observed that there was a reticence amongst older practitioners to adopt more recent techniques. There is a very apparent deficit in the knowledge of potential benefits of using Electronic Apex Locators in routine endodontic treatment.