Confocal laser scanning evaluation of the influence of ledges on root canal disinfection.

The aim was to analyse the influence of an apical ledge on root canal disinfection. Forty-four single-rooted teeth were micro-CT scanned and inoculated with Enterococcus faecalis. In Group S shaping was performed with ProTaper Next (PTN) up to X3 at working length (WL). In Group L an apical ledge was created with K-Files #40 and shaping completed up to PTN X3. NaOCl 5% and EDTA 10% irrigant solutions were alternated. Confocal laser scanning microscope (CLSM) and viability staining were used to analyse the proportions of dead (red) and live (green) bacteria and penetration ability inside dentinal tubules. Data were analysed with the Mann-Whitney test with Bonferroni correction (p < 0.05). In Group L the amount of red fluorescence resulted significantly lower, and penetration ability was decreased in the apical and middle portion (p < 0.05). The presence of an apical ledge may negatively influence the disinfection both in the apical and middle third.

Effect of Different Electroconductive Root Canal Irrigations on the Accuracy of Different Apex Locators: An In Vitro Comparative Study.

Aim: An accurate working length (WL) estimation is fundamental to a successful endodontic therapy. The objective of this comparative in vitro research was to investigate the performance of iPex II and the Root ZX Mini electronic apex locators (EALs) in measuring root canal WL with different irrigant solutions and their relation to the electrical conductivity of irrigation solutions. Materials and Methods: Seventy sound permanent lower premolar teeth, each with a single root and developed apices, were used. Under an X15 stereomicroscope, the real working length was determined with the aid of a #10 file. After that, teeth were placed into an alginate model, and the iPex II and Root ZX Mini were used for the detection of electronic working length with various irrigants. Seventy teeth were randomly distributed into seven groups, 10 per each group (group I: dry canal; group II: distilled water; group III: ozonated water; group IV: 5% sodium hypochlorite (NaOCl); group V: 2% chlorhexidine, group VI: 17% ethylenediaminetetraacetic acid (EDTA) solution, and group VII: 17% EDTA gel). The difference in WL was calculated by deducting real working length from its electronic working length. The study also evaluates the electrical conductivity of the seven endodontic irrigant solutions. The two-way analysis of variance (ANOVA) test was used for statistical analysis. Results: Statistically, neither both types of EALs (P = 0.088) nor various irrigating solutions with varying electrical conductivities (P = 0.099) significantly affect the accuracy of EL estimation. Conclusions: There were no significant differences between the accuracy of the Root ZX Mini and the iPex II. The accuracy of both apex locators is unaffected in the presence of various irrigation solutions with varying electrical conductivities in this research.

In-vitro Evaluation of the Accuracy of Electronic Apex Locators and Cone Beam Computed Tomography in the Detection of Oblique Root Fractures.

OBJECTIVES: This study aimed to compare the accuracy of cone-beam computed tomography (CBCT) scanning and three different electronic apex locators (EALs) in the detection of simulated oblique root fractures (ORF) in different localizations. METHODS: The study utilized a total of eighty human maxillary incisors, which were categorized into two groups based on the location of the ORF (apical and middle third of the root) formed on the buccal side of the root surface. The measurement of the distance between the incisal edge and the intersection of the ORF with the root canal was conducted using a stereomicroscope. This measurement is referred to as the actual working length (AWL). Additionally, three EALs-Dentaport ZX, EndoRadar Pro, and Propex II-were utilized to determine the electronic working length (EWL). Furthermore, CBCT images were employed to assess the distance, known as the CBCT working length (CWL). The differences were determined by subtracting AWL from EWL and CWL. RESULTS: Based on the accuracy of the devices, there were no significant differences observed among Dentaport ZX, EndoRadar, Propex II, and CBCT measures in both the apical and middle third HRF groups, within the acceptable range of 0.5 mm and 1 mm. CONCLUSION: The accuracy of Dentaport ZX, Propex II, and CBCT was higher in the middle third ORF group compared to the apical third ORF group, with a tolerance of 0.5 mm. However, there were no significant differences seen among the devices.

The Accuracy of Cone Beam Computed Tomography Scans in Determining the Working Length in Teeth Requiring Non-surgical Endodontic Treatment: A Retrospective Clinical Study.

BACKGROUND: Endodontic treatment aims to eradicate both microbial infection and inflammatory processes within the root canal space as well as in the periapical (PA) region of the tooth. To achieve this, the canals should be cleaned, shaped, disinfected, and obturated to the proper working length. Clinically, the working length is described as the measurement from the coronal reference point to the physiological apex located at the apical foramen. In the available literature, electronic apex locators (EAL) with periapical (PA) radiographs are the most reliable and precise tools for determining the working length in routine root canal treatment. Therefore, the aim of this retrospective clinical study is to evaluate if cone beam computed tomography (CBCT) scans are reliable and accurate in measuring endodontic working length compared to standard clinical measurement methods. METHODS: Patients who fit the inclusion criteria were identified. A postgraduate endodontic resident blinded to the cone beam computed tomography scan results treated all teeth in the field of view that needed endodontic treatment. The root canal length was determined using J Morita Root ZX II apex locator (J Morita Corp., Kyoto, Japan) and periapical radiographs. The dental radiology specialist interpreted the pre-existing cone beam computed tomography (CBCT) scan images and determined the working length. Statistical comparisons of the working length measurements of EAL and CBCT were performed using paired sample t-tests after verifying normality. RESULTS: No statistically significant differences in the working lengths were found in all canals with the exception of the palatal canal only (t=2.16, p=0.034), suggesting consistent measurements between EAL and CBCT. CONCLUSION: In teeth requiring endodontic treatment, pre-existing cone beam computed tomography scan images are accurate as electronic apex locators when determining the working length. A limitation of this study is that it only includes a limited number of samples and is affected by operator variation.

Accuracy of an Electronic Apex Locator (EAL) in Measuring the Working Length of Root Canals in Comparison With Radiographs: An In Vivo Study.

INTRODUCTION: Traditionally, radiographs were used to assess the working length of root canals. However, the use of Electronic Apex Locators (EAL) may be a non-invasive alternative. This study aimed to evaluate the accuracy of the electronic apex locator (EAL) compared to radiographic measurements in determining the working length of root canals. METHOD: The study assessed the performance of EALs in different scenarios, including the presence of blood and pulp tissue, the use of ethylenediaminetetraacetic acid (EDTA), sodium hypochlorite (NaOCl) as an irrigant, and post-instrumentation with normal saline. An electronic apex locator (DTE DPEX-V; Woodpecker, China) was used alongside traditional radiographs to measure the working length in 144 root canal treatments. Bland-Altman analysis was used to compare the measurements between EAL and radiographs using Jamovi software, v2.4.8 (https://www.jamovi.org/). RESULT: The findings revealed strong correlations between EAL and radiographic measurements across all testing environments, with Pearson's correlation coefficients ranging from 0.944 to 0.998. The Bland-Altman analysis suggests bias; the average difference was negative and close to zero (Pulp: -0.354, EDTA: -0.0972, NaOCl: -0.0382, Saline: -0.0139) when EAL measurements were compared to radiographic measurements. CONCLUSION: The working length measurement of root canals using an electronic apex locator such as DTE DPEX-V is comparable to traditional radiographic measurements. The use of irrigants improves the measurement. The EAL has the potential to be an alternative to the invasive radiograph for root canal length measurement.

Outcomes of root canal treatments with three different sealers for 120 fractured maxillary fourth premolar teeth in small-to medium-sized dogs.

Introduction: Tooth fracture is one of the most common traumatic maxillofacial injuries in dogs and cats. For fractures with pulp exposure occurring in functionally important teeth, the literature indicates that root canal treatment (RCT) is an effective therapy option that may be the remedy of choice before extraction. The most commonly reported fractures in the United States involve canine teeth; however, fractures of the maxillary fourth premolars are more common in Korea, where there are many small-and medium-sized dogs. RCT mechanically and chemically removes pulp tissue and bacteria (cleaning and shaping) from the infected root canal, and obturates the root canal with filling material to restore tooth functionality without inflammation. Various techniques, instruments, and materials used in humans have been modified for application in veterinary dentistry. Methods: This study analyzed the results of RCT of the maxillary fourth premolar in 120 small-and medium-sized dogs (weighing less than 25 kg) using three different sealers (silicone-based sealer, bioceramic sealer, and calcium hydroxide-based sealer) through a simple application of the single-cone technique. Results: The overall success rate of RCT in maxillary fourth premolars was 90.83%, with 8.33% no evidence of failure (NEF) and 0.83% failure. Discussion: There were no significant differences between the three different sealers. Furthermore, preexisting periapical lesion (PAL) was reconfirmed as a factor in reducing the success rate of RCT. In addition, the working length and master apical file of each root were analyzed in our study as a novel reference for endodontic veterinarians.

Comparative evaluation of accuracy of working length determination with fifth-generation apex locator using two different techniques: An in vitro study.

Context: Accurate working length (WL) determination is essential for successful root canal therapy. Aim: The aim of this study was to compare the difference between two different techniques in locating minor constriction using fifth-generation electronic apex locator. Settings and Design: A detailed protocol explaining the procedures of the study was submitted to the institutional ethics committee. Subjects and Methods: Forty extracted human permanent canine teeth were selected. WL was measured three times for each sample by three different examiners for both the conventional and experimental techniques at different time intervals. Interexaminers were blinded to their measurements, and the person who analyzed mean value was also blinded with techniques. Finally, radiographic working length was obtained using 15 size K-file. A size 20 K-file was cemented into the measured position with glass ionomer cement. Each tooth was viewed under a stereomicroscope at ×40 magnification. The distance from the file tip to the root apex was measured and calibrated to the nearest tenth of a millimeter. Statistical Analysis Used: Using Stata statistical software (Version 17, Statacorp, College Station, Texas, USA). The agreement between raters and techniques was determined using intraclass correlation coefficient "ICC" and Bland-Altman plot. Results: The "experimental method" (0.95, 95%) showed better agreement between the raters in comparison with the "conventional method" (0.93, 95%). Conclusions: The experimental technique showed perfect agreement between examiners in locating the minor constriction of the apical foramen.

A Global Overview on Electronic Apex Locator Use From 1968 to 2023: A Bibliometric Analysis.

INTRODUCTION: This bibliometric review analyzed the research trends and main characteristics of articles related to Electronic Apex Locators (EALs). METHODS: The search was conducted in November 2023 on the Web of Science Core Collection. Narrative and systematic reviews, observational and intervention studies, laboratory, and clinical studies were included. Two researchers selected the articles and extracted the number of citations, year of publication, journal, study design, theme, country, continent, institutions, author, and keywords. Collaborative networks were generated using the VOSviewer software. The relationship between data were determined by Spearman's correlation. RESULTS: The search resulted in 374 articles, of which 294 were included. Most cited article had 175 citations. The most prevalent journal was the Journal of Endodontics (n = 84). The predominant study design was the laboratory-based (n = 223). The predominant theme was the EALs accuracy (n = 175). Piasecki L was the author with the highest number of articles (n = 11). Only 8.16% of the studies were conducted in deciduous teeth. The country with the most studies was Brazil (n = 46). Asia (n = 107) was the continent with the highest number of publications. There was a weak positive correlation between the number of citations and impact factor (rho = .294), and a strong negative correlation between citations and year of publication (rho = -.710). CONCLUSIONS: The majority of articles were laboratory-based studies conducted on permanent teeth, focusing on the accuracy of EALs. Future studies should prioritize research on deciduous teeth, systematic reviews, and, notably, clinical trials.

Management of Apical Third Root Fractures in Radiculomegaly of Mandibular Anterior Teeth: A Rare Case Report.

In this case report, two uncommon fractures of the root located at the apex of the mandibular anterior teeth region were successfully treated and preserved using non-surgical endodontic procedures. These teeth possess a unique size, characterized by the presence of exceptionally elongated lateral incisors measuring approximately 29 mm, central incisors measuring approximately 25 mm, and canines measuring approximately 30 mm. For the lower left central incisor, the root canal was carefully navigated to the coronal fragment, whereas the apical fragment was left undisturbed and preserved. In the case of the remarkably elongated lower right lateral incisor, the process of 'unification' between the apical and coronal fragments was accomplished through the utilization of Gutta-percha and Ah plus sealer. Subsequently, the mandibular anterior teeth were stabilized and immobilized using dental splints for a duration of one and a half months, with regular follow-ups conducted over a span of six months and one year, during which positive healing outcomes were observed.

Comparative evaluation of digital radiography, electronic apex locator and simultaneous working length determination on postoperative pain after root canal treatment: a randomized clinical trial.

Purpose: The study aimed to compare postoperative pain after root canal preparation using three different methods of working length determination. Materials and methods: 60 patients diagnosed with symptomatic irreversible pulpitis were randomly divided into three groups based on the method of working length (WL) determination. Group 1: digital radiograph (DRG), Group 2: electronic apex locator (EAL), Group 3: the simultaneous working length control (SLC) method using an endomotor with an integrated apex locator. The root canal treatments were completed in a single visit, and patients were asked to record their pain response using the Visual Analog Scale (VAS) at 6, 24, 48, and 72 hours postoperatively. Results: Group 1 (DRG) recorded the highest postoperative pain score, while the lowest was recorded by Group 3 (SLC). There was a statistically significant difference in the VAS pain scores between DRG and SLC (p<0.05) at 6-, 24- and 48-hour intervals. Conclusion: Within the limitations of this study, it can be concluded that the SLC can be a helpful working length determination technique to reduce postoperative pain.

Computational fluid dynamics investigation on the irrigation of a real root canal with a side-vented needle.

BACKGROUND: Root canal therapy is one of the main treatments for root canal diseases, and effective irrigation is the key to successful treatment. Side-vented needle is one of the commonly used needle types in clinic. In the real root canal, due to the influence of the curvature of the root canal, the irrigation flow field in different needle directions shows obvious differences. At the same time, changes in root canal curvature and working depth will lead to changes in irrigation efficiency and the flow field. Both the mainstream of the irrigation flow and the shear stress near the wall changes significant. Consequently, either the replacement in the root canal or the removal efficiency of the smear layers is apparently modified. MATERIALS AND METHODS: In this paper, the permanent root canal of the maxillary first molar prepared until 15/04 were scanned by micro-CT, and then imported into the software for 3D reconstruction. The key parameters of flushing efficiency of 30G side needle at different working depths of 4.75 mm, 5 mm, 5.25 mm and 5.5 mm were compared. Meanwhile, the simulated models with different curvatures of 0°, 5°, 10°, 20° and 30° based on the real root canal were reconstructed to investigate the curvature effect on the irrigation efficiency. RESULTS: The results show that moderate working depth (such as 4.75 mm and 5.25 mm in present paper) helps to improve the replacement capacity of irrigation flow. At the same time, the apical pressure decreased as the working depth increased. The curvature of the root canal seriously affects the removal depth of the smear layers of the root canal. A root canal with a large curvature (especially 20° and 30°) can significantly improve the difficulty of irrigation. CONCLUSIONS: (1) Moderate working depth helps to improve the displacement capacity, the ERD of the irrigation flow is generally improved at the working depths of 4.75 mm and 5.25 mm, and the apical pressure will decrease with the increase of working depth. (2) The large curvature of the root canal can significantly improve the difficulty of irrigation. The curvature of the root canal can severely influence the removal depth of the smear layer on the wall. It can be found both the span and the depth of the ESS for little curvatures (5° and 10°) root canals are higher than those for large curvatures (20° and 30°).

Can ultrasonography be used to determine working length in endodontic treatment? An in vitro study.

This study was conducted to evaluate efficacy of ultrasonography (USG) in determining working length in in-vitro conditions. Twenty five access cavities of maxillary incisor teeth were opened and actual working lengths (AWL) were measured with dental operating microscope. The working length were then measured with an electronic apex locator and USG. USG and apex locator measurements were statistically analyzed using one sample t-test and compared with AWL. The mean AWL measurment was 20.68 mm. USG measured the working length slightly longer (21.09 mm) than the measurements of apex locator (20.64 mm). Statistical analysis showed that the USG method provided similar measurements to electronic apex locators and with no statistical difference with actual working length (P < .05). USG emerges as a promising method for working length measurement that allows simultaneous visualization of root tip anatomy in cases where electronic apex locators may be insufficient and there is buccal cortical bone loss.

Evaluation of changes in root canal length and accuracy of the electronic apex locator during different stages of endodontic treatment and retreatment.

This study evaluated changes in the root canal length (RCL) and the accuracy of the electronic apex locator (EAL) during the different stages of endodontic treatment and retreatment. Fifty-six mesial root canals of mandibular molars were selected. The actual root canal length (AL) of the canals was obtained by inserting a size 15 hand file up to the apical foramen, under magnification. The electronic lengths were obtained at the "APEX" mark of Root ZX II, using an alginate model. Both measurements were performed at three different stages of the initial root canal treatment-unflared, flared, and concluded-and at two stages of retreatment, after achieving patency and repreparation. Data were statistically analyzed and the significance level established was 5%. All stages produced a significant reduction in the AL (p < 0.05). The greatest variation was observed between the unflared-flared stages (0.2 mm) and between concluded-patency stages (0.09 mm), with no difference between them (p > 0.05). The accuracy of Root ZX II was negatively affected after achieving patency, presenting statistically significant difference compared to the other stages (p < 0.05). A significant reduction in the RCL was observed along the different stages of endodontic treatment and retreatment. The EAL was accurate to measure the root canals in most stages, except after achieving patency for endodontic retreatment. Determining and monitoring the RCL is an essential step towards a favorable prognosis, since it reduced along the different stages evaluated. Root ZX II was not accurate for endodontic retreatment.

Do working length and proximal screw density influence the velocity of callus formation in distal tibia fractures treated with a medial bridge plate?

INTRODUCTION: Aim of our study was to evaluate the influence of working length and screw density on callus formation in distal tibial fractures fixed with a medial bridge plate. MATERIALS AND METHODS: 42 distal tibia fractures treated with a bridge plate were analyzed. Minimum follow-up was 12 months. mRUST score (modified Radiographic Union Scale for Tibial fractures) was used to assess callus formation. Working length and screw density were  measured from post-operative radiographs. RESULTS: 39 (92.9%) fractures healed uneventfully. 32 (76.19%) patients showed signs of early callus formation 3 months post-surgery. In these patients a lower screw density was used compared to patients who didn't show early callus (33.4 vs. 26.6; p = 0.04). No differences was noticed in working length. CONCLUSION: Bridge plate osteosynthesis is a good treatment option in distal tibia fractures. In our series increasing the working length was not associated with a faster callus formation in distal tibia fractures. Conversely, a lower screw density proximally to the fracture site was associated to a faster callus growth.

Fracture gap and working length are important actionable factors affecting bone union after minimally invasive plate osteosynthesis for the treatment of simple diaphyseal or distal metaphyseal tibia fractures.

INTRODUCTION: Indirect reduction of minimally invasive plate osteosynthesis (MIPO) can often result in delayed union in tibia fractures. This study evaluated several factors in MIPO in relation to bone union. HYPOTHESIS: We hypothesized that the fracture gap, plate - tibia distance, or working length would have a substantial effect on the tibia union rate. MATERIALS AND METHODS: Forty-one patients with simple diaphyseal or distal metaphyseal tibia fractures who underwent internal fixation surgery using the MIPO technique were divided into two groups: patients with delayed union and patients without delayed union. Non-actionable factors involving AO/OTA classification, fibula fracture and actionable factors including postoperative fracture gap, plate - tibia distance, working length in relation to parameters of bone union were compared between the two groups. Also cumulative rates of bone union and risk factors of delayed union according to variables of interest were investigated. RESULTS: AO/OTA classification, site of fibula fracture, postoperative fracture gap, working length, and bone union rate of the two groups significantly differed (p<0.05). The cumulative rate of bone union during 1-year follow-up according to 43A tibia fracture, distal fibula fracture, fracture gap, and working length significantly differed between the two groups (p<0.05). By univariate Cox proportional hazards model, 43A tibia fracture, distal fibula fracture, facture gap, and short working length were risk factors for delayed union (p<0.05). DISCUSSION: Non-actionable factors involving AO/OTA classification, distal fibula fracture and actionable factors including postoperative fracture gap, working length were significant factors affecting bone union after MIPO. The present study indicated that small fracture gap and long working length during MIPO might facilitate bone healing in tibia fracture. LEVEL OF EVIDENCE: IV; single-center retrospective cohort study.

Influence of Embedding Medium on iPex Electronic Apex Locator Accuracy: An Ex Vivo Comparative Study Using Alginate, Saline, and Gelatin Models.

AIM: Accurate working length determination during root canal treatment is essential for achieving successful outcomes. This study aimed to evaluate the impact of embedding medium on the accuracy of iPex electronic apex locator (EAL). MATERIALS AND METHODS: Sixty-one extracted single-rooted teeth were decoronated and coronally flared with Gates-Glidden burs. Actual canal length (ACL) was obtained by introducing a size 8 K-file until its tip reached the most coronal border of the apical foramen. This step was performed thrice and then averaged. Deducting 0.5 mm from the ACL provided the working length (WL). The teeth were randomly placed in plastic containers filled with freshly mixed alginate, gelatin, or saline, with the lip clip placed in the medium. The blinded operator obtained electronic measurements using iPex by advancing a K-file with a size compatible with the canal attached to the file clip and advanced until the 0.0 mark, then withdrawn to the 0.5 mark. This step was performed thrice and then averaged. Data were analyzed using ANOVA and Tukey's post hoc test, with significance level set at 5% (α = 0.05). RESULTS: The mean difference between WL and iPex length obtained in the gelatin model was significantly longer than the difference with mean iPex length in alginate (p = 0.005) and in saline (p < 0.001). There was no significant difference between iPex readings obtained in alginate and saline (p = 0.249). CONCLUSION: The use of freshly mixed alginate or saline for ex vivo assessment of iPex is recommended, whereas the use of gelatin could increase the chances of readings longer than looked for. CLINICAL SIGNIFICANCE: Identifying the optimum embedding medium for ex vivo testing of EALs permits the comparison and assessment of several factors affecting EALs' precision under standardized conditions. This helps in understanding EAL performance in vivo and in optimizing its clinical utilization.

The Effect of Coronal Pre-flaring and Type of Root Canal Irrigation on Working Length Accuracy Using Electronic Apex Locators.

Background: Successful root canal treatment is influenced by the apical extent of root canal preparation and the eventual root canal filling. Achieving the full working length until the apical constriction, which is usually 0.5 - 1 mm shorter than the anatomical apex, is crucial. Electronic apex locators were used to detect the working length more accurately. There are six generations of electronic apex locators in the market. The selection of the appropriate irrigation with each apex locator for accurate working length determination is not fully investigated. Methods: The actual working lengths of 120 freshly extracted human single-rooted teeth were measured and compared with their working lengths using 3 rd generation (Root ZX) followed by 6 th generation (Raypex 6) apex locators in dry medium, presence of 5.25% sodium hypochlorite, and 2% chlorhexidine, without coronal pre-flaring and after coronal pre-flaring using the same irrigating media. Data were collected, tabulated, and afterward analyzed using one-way ANOVA with post-hoc to evaluate the significant difference in average working length between actual working length, Root ZX, and Raypex 6 apex locator working lengths accuracy. Results: The significant results were shown in roots that were coronally pre-flared and their working lengths were measured in a dry medium using Raypex 6 apex locator. While using the Root ZX apex locator, the most accurate results were shown in roots that were coronally pre-flared and their working lengths were measured while using a chlorhexidine irrigating solution. Conclusions: It is concluded that it is very important to know the specific irrigating medium to be used with each specific electronic apex locator to achieve the most accurate working length results.

Accuracy of Root ZX Electronic Apex Locator in Relation to Two Different Employment Protocols: An In Vitro Study.

Objective The aim of this study is to determine the apical level of the root canal, whether it is the apical foramen or a level coronal to it, that Root ZX (J. Morita Co., Kyoto, Japan) targets and to identify its employment protocol that provides better accuracy. Methods Actual lengths (ALs) of 75 extracted single-rooted teeth were obtained by inserting a K-file size 8 until its tip was in level with the most coronal border of the apical foramen. Reference length (RL) was calculated by deducting 0.5 mm from AL. Roots were placed in porous sponge block soaked with Ringer's solution, and canals were irrigated with 2 mL of 5% sodium hypochlorite. The blinded operator used Root ZX to measure lengths with K-file size 8. In the first tested employment protocol, the file was advanced to the "APEX mark" of the digital display, and the length was obtained. The second employment protocol followed the manufacturer's recommendations by inserting the file until the "APEX mark" followed by its withdrawal to the "0.5 mark." Stability of the digital meter for 5 seconds was mandatory before recording the lengths. All measurements were repeated one week later and then both measurements were averaged to represent "APEX mark" and "0.5 mark," respectively. Data were analyzed using t-test, with significance set at 0.05. Results Regardless of the employment protocol, most registered lengths were longer than targeted. The mean "APEX mark" was significantly longer than the mean AL (P=0.000), and the mean "0.5 mark" was significantly longer than the mean RL (P=0.000). Although the mean "0.5 mark" was longer than the mean AL, the difference was not significant (P=0.07). Conclusion The apical level of the root canal targeted by the Root ZX was the apical foramen. The most accurate employment protocol to achieve that is to use the Root ZX according to the manufacturer's recommendations.

In vivo Study to Evaluate the Effect of Instrument Size on the Accuracy of Three Different Apex Locators when Various Irrigation Solutions are used in Vital and Non-Vital Teeth.

Introduction: Root canal success requires working length (WL) optimization. The current study examined how different apex locators on vital and non-vital teeth responded to instrument size. Materials and Methods: Three hundred patients (180 men and 120 women) receiving root canal therapy at the department of Conservative Dentistry and Endodontics were evaluated. Therefore, we determined that 200 of the patients' teeth (100 vital and 100 non-vital teeth from the upper and lower jaws' first molars) qualified for inclusion in our study. The pulp chamber was accessed using a sterile round bur. The coronal region of the root canal was preflared with successive Gates Glidden drills (Mani Inc. Japan) and irrigated with any one of the solutions 3% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), or 17% ethylenediaminetetraacetic acid (EDTA) solution after checking canal patency with a size #10 K file, where (#-number). Later, the working length was established using Ingle's technique and a radiovisiograph (RVG) 0.5 mm short of the radiographic apex. Two endodontists approved this RVG. Results: Overall, the #15 K file and apex locators did not differ from Ingle's method. While the #8 K file differs significantly from all apex locators, the #10 K file showed a significant difference with all apex locators except Root ZX with 2% CHX (P = 0.06). Irrigation didn't influence apex locators' accuracy. Conclusion: Even in the presence of irrigating solutions, electronic apex locator (EAL) can be utilized to calculate the working length with accuracy. The apex locators #15 k files, #10 k files, and #8 k files showed the most promising results.

Accuracy of the electronic apex locator, tactile, and radiographic methods in working length determination.

Background: Determination of working length (WL) is necessary for the successful outcome of root canal treatment (RCT). Common methods in WL determination include tactile, radiographic, and electronic apex locators (EAL). Aim: The aim of this study was to compare three methods of WL determination to the actual visualization of the apical constriction (AC). Materials and Methods: Consecutive patients with indications for extraction of single-rooted single canal teeth at the University of Ghana Dental School clinic were randomly assigned to three groups. In-vivo root canal WL was determined by tactile sensation, digital radiography, and a 5th generation EAL (Sendoline S5). Files were cemented in the canals after the in-vivo measurements. The apical 4-5 mm of the roots was trimmed to expose the inserted files and the AC. Actual WL, as determined by visualization of the AC, was done using a digital microscope. Different WLs were then compared for the various groups, and the mean actual canal lengths were reported. Results: EAL accurately predicted the AC in 31 (96.9%) teeth, while the digital radiographic and tactile sensation methods accurately predicted the constriction in 19 (59.4%) and 8 (25%) teeth, respectively, in the study population. The mean working canal lengths for single-rooted teeth showed no observable difference among sexes, age categories, and side of the jaw. Conclusion: The EAL provided more reliable and accurate WL measurements for single-rooted teeth among Ghanaians, compared to digital radiography and tactile methods.