Canal Length Research Articles

Complex Relationships between Milking-Induced Changes in Teat Structures and Their Pre-Milking Dimensions in Holstein Cows.

The study aimed to explore the relationship between teat structure dimensions and their short-term reaction to milking, to find the optimal dimensions of teat structures in relation to milking-induced teat tissue changes. Teat structures (teat length, canal length, thickness at barrel and apex, wall and cistern width) were measured by ultrasonography before and after milking for 38 Holstein cows at the beginning, middle, and end of lactation. We found that milking-induced changes in teat structures significantly depended on their pre-milking size. Furthermore, we observed that some teat structures and their changes were interconnected, and some did not affect each other. For example, changes in the barrel thickness and cistern width were affected by all structures, while the canal and apex did not influence each other. We deduced that more favorable changes were observed for teats of medium length, medium barrel and apex thickness, with teat canals of medium length, but with wider cisterns and thinner walls. The results of this study may help improve research in the area of milking-induced changes in teat morphology. Our findings could help understand potential health risks to animals in relation to teat morphology, milking equipment, and machine settings.

Bifid Mandibular Canal: A Proportional Meta-Analysis of Computed Tomography Studies.

Growing body of evidences showed different grades in prevalence of bifid mandibular canals. Because the previous reviews focused solely on patient-level occurrence, hemi-mandible-level prevalence, bilateral symmetry, length, and diameter of bifid mandibular canals were required to be estimated collectively. The research question of this meta-analysis was "What is the prevalence of bifid mandibular canal among patients seeking computed tomography examinations"? In vivo, computed tomography, and cross-sectional studies were eligible. Studies, with less than 100 subjects or anatomic site restriction or controlled class of bifid mandibular canal, were excluded. Joanna Briggs Institute (JBI) critical appraisal tool for prevalence studies was used to assess methodological quality of all included studies. Random effect meta-analyses for proportion of bifid mandibular canal were done. 40 studies met the inclusion criteria. All studies were selected for both systematic review and meta-analyses. Totally, 17714 patients and 31973 hemi-mandibles were included. All eligible studies showed moderate risk of bias on average. Resulting from the random effect model, more than 20% of patients seeking computed tomographic examinations had bifid mandibular canals (BMCs) which penetrated into slightly more than 14% of hemi-mandibles. Of the patients having bifid mandibular canals (BMCs), nearly 23% exhibited such anatomy on both sides of their mandibles. Estimated mean length and diameter of the accessory canals of bifid mandibular canals were 12.17 mm and 1.54 mm, respectively. The geographical locations, classifications, reliability test, and voxel size of computed tomography were all implicated in the prevalence of bifid mandibular canals along with gender and laterality, although considerable heterogeneity and bias were detected.

Three-dimensional assessment of the mandibular lingual foramina with implications for surgical and implant therapy: A multicentre cross-sectional study.

Treatment planning for dental implants in the anterior mandible is often complicated by the presence of vascular structures. The aim of our study was to investigate the prevalence, location and morphology of the mandibular lingual foramen (LF) through cone beam computed tomography (CBCT) scans and contribute to its anatomical knowledge in an Indian population. A total of 400 mandibular anterior CBCT scans from 4 centers were included in this retrospective analysis. The vertical distance from alveolar crest (Hcre) and inferior border of mandible (Hinf) to the LF, horizontal distance from lingual canal to labial cortical plate (LC-CP), length of the lingual canal (LLC) and diameter of the LF were measured. Data was analysed using Wilcoxon signed rank test and compared between median and lateral LF. 14 (3.5%) scans were excluded due to non-visualization of LF. A lateral LF was detected in 149 scans (38.6%), predominantly in the canine region (61.7%). Hcre was significantly higher for median LF (16.35±4.59mm) than lateral LF (12.94±3.92mm) (p<0.001), while Hinf did not show significant difference between median (11.38±3.62mm) and lateral (12.94±3.92mm) LF (p=0.0032). The LC-CP, LLC and diameter of LF averaged at 5.05±1.76mm, 6.26±1.82mm and 0.88±0.72mm respectively. The LF can be visualized in CBCT scans with a prevalence of 96.5%. This study stresses on the need for a CBCT, prior to surgeries in anterior mandible to avoid excessive bleeding episodes.

Taper 0.06 Versus Taper 0.04: The Impact on the Danger Zone

IntroductionThis study aimed to evaluate the effects of root canal enlargement on the danger zone (DZ) of mandibular molars. MethodsThirty mesial roots of mandibular first molars were scanned in micro-computed tomography (S1). Canals were sequentially enlarged with rotary instruments up to sizes 30/0.04 (S2) and 30/0.06 (S3). The dentin thickness was measured at 0.1-mm intervals after each preparation step (n = 2964 slices). Root level and position of the DZ were also recorded. Data were compared using analysis of variance with Bonferroni pairwise comparison, Cochran's Q method, and Pearson's test (α = 5%). ResultsComparing the specimens before (S1) and after (S2 and S3) preparations showed a significant reduction in the thickness of the DZ (P < .05), as well as between S2 and S3 steps (P < .05). At S1, the DZ was mostly located in the middle third of the root, but after preparation, it shifted toward the coronal direction (P < .05). Both S2 (P = .004, r = 0.508) and S3 (P = .004, r = 0.506) preparation steps showed a positive correlation between canal length and the root level of the DZ. At S1, the DZ was positioned toward the distal and mesial in 73.4% (n = 22) and 26.6% (n = 8) of the specimens, respectively. After S3, the number of specimens with DZ positioned toward the mesial aspect of the root significantly reduced to 3.3% (n = 1), whereas none of the specimens with DZ positioned toward the distal changed its position after root canal enlargements (P > .05). ConclusionOverall, the enlargement of mesial canals of mandibular first molars with final instruments sizes 30/0.04 and 30/0.06 affected the thickness, root level, and position of the DZ.

RECONSTRUCTION OF GASTROINTESTINES AND ADJACENT STRUCTURES IN THE EARLY PERIOD OF HUMAN ONTOGENESIS

The article describes the laying periods of: the stomach (embryos 4.5-5.0 mm long), the circular layer of the muscle membrane; gastric pits (embryos 14.7-15.0 mm long); gastric glands are formed in pre-fruits with a length of 66.0-68.0 mm. On the basis of graphic and computer reconstruction, the rotation of the stomach around the longitudinal axis of the embryo, the relationship of the stomach with neighboring structures – the liver, gall bladder, duodenum and pancreas – are studied. The fetal stomach undergoes heterogeneous and multifactorial rotation as a result of increased growth of the stomach wall on the left and increased gastric motility caused by the previous increase in the mesentery, and that the direction of rotation is determined by the forces exerted on the stomach and gastric mesentery by neighboring organs. The shape of the stomach is caused by a change in the dorsal-left sections of the tab, which leads to rapid growth compared to the ventroright sections. The cranial part of the stomach is wider than the caudal part. Uneven growth is observed not only in transverse, but also in cranial directions. The cranial part of the stomach is wider than the caudal part. A signifi cant change in the stomach occurs during 7.5 to 8.5 weeks. Due to the protrusion of the upper part of the large curvature, the bottom is formed. In an embryo of 4.5 weeks, the lumen of the loops of the proximal part of the intestinal tube has an oval shape and slightly exceeds that of the caudal part of the digestive tract. the topographical relationship of the stomach with the surrounding organs changes signifi cantly during the prenatal period of development. In embryos of 4.5-8.0 mm, the lining of the stomach is located deep behind the liver, which surrounds it on three sides. Dorsal to the stomach lining are the lining of the left adrenal gland, the left mesonephros, and the lining of the spleen. Cranially, the lining of the stomach abuts the lung to the left. At the end of the prenatal period, the diameters of the portal of the stomach, the portal canal, the bulb of the duodenum, the length of the portal canal along the lesser curvature and the portal canal along the greater curvature, and the size of the angle of the stomach were determined.

Artificial intelligence in conservative dentistry and endodontics: A game-changer.

Artificial intelligence (AI) technology has mostly been used by dental practitioners to diagnose problems, plan treatments, make clinical judgments, and predict outcomes. In endodontics, convolutional neural networks and artificial neural networks, two types of (AI) models, have been used to study the anatomy of the root canal system, measure the length of root canal, identify periapical pathology and root fractures, prediction of success of retreatment procedures, and dental pulp stem cells viability. The goal of this review is to assess AI's role in conservative dentistry and endodontics.

Radix entomolaris: A morphological variable of human dentition with anthropological relevance. A study on a Chilean population.

The existence of a third root in the mandibular first molars may have implications for certain dental treatments; however, its greatest relevance could be in anthropological and forensic sciences, because its prevalence varies significantly according to ethnic groups. The purpose of this research was to determine the prevalence of radix entomolaris (RE) in a sample of Chilean people. A random sample of 1330 digital periapical radiographs of endodontically treated mandibular first molars (551 males and 779 females, aged between 18 and 87 years) were evaluated. The prevalence of RE, its distribution by sex and root canal lengths were determined. Evidence demonstrated that the formation of RE is associated with ancestry and its frequency is variable according to populations studied, being more frequent in Asians and Native Americans. The prevalence of RE in the studied people was 3.16%, similar to frequencies reported in European individuals (3.4%-4.2%). The 61.90% of RE were located at the right side of the mandible and 38.10% at the left side. The average working length of RE was 19.52 mm. No statistically significant differences in frequencies were observed by sex (p = 0.19). The prevalence of RE varies among continental population groups. However, due to human migration, the frequency of this physical trait could be modified in specific geographic regions. The observed prevalence of RE in the study group was similar to the prevalence ranges observed for European ancestry populations and it was considerably lower than the data reported for non-Europeans. The absence of sexual dimorphism is consistent with results of previous studies performed worldwide.

Incorporating temperature into seepage loss estimates for a large unlined irrigation canal

Quantifying seepage losses from unlined irrigation canals is necessary to improve water use and conservation. The use of heat as a tracer is widely used in quantifying seepage rates across the sediment–water interface. In this study, field observations and two-dimensional numerical models were used to simulate seepage losses during the 2018 and 2019 irrigation season in the Truckee Canal system. Nineteen transects were instrumented with temperature probes and stage recording devices for inverse modeling to derive seepage flux and volumetric losses over the 39 km length of canal. The numerical models for each transect were calibrated and validated using the two-year dataset. Soil zones and observation data were used in each numerical model to help guide calibration of vertical and lateral heat and fluid fluxes. Model simulations were used to derive multivariable regression equations that consider stage, temperature, and hydraulic gradient. The results demonstrate the value of long-term datasets that illustrate the seasonality of groundwater levels, siltation, stage, and temperature on seepage rates. Seepage rates estimated by the numerical models range from 0.16 to 4.6 m3/d m−1. Total annual volumetric losses estimated for 2018 and 2019 were 1.6 × 10-2 to 1.2 × 10-2 km3, respectively. The seepage losses estimated by this study account for 32 % to 41 % of the inflow volumes. Regression models were able to reproduce seepage time-series simulated by the numerical models reasonably well. In arid environments, water diverted into irrigation canals may be influenced by seasonal variations in temperature sufficient to influence the water accounting of conveyed surface flows.

To the north: eDNA tracing of the seasonal and spatial dynamics of fish assemblages along the world's largest water diversion project

Extensive water diversion projects that have been increasingly installed worldwide transport essential water resources as well as a large number of biota. However, studies of the dynamic processes of such transport have been limited. The South-to-North Water Diversion Project of China is the largest manmade water diversion system ever constructed. Here, in a year-long project, we used environmental DNA (eDNA) metabarcoding to assess fish biodiversity and assemblage composition along the Project's 1277-km main canal, while also investigating the temporal, spatial, and functional trait drivers of changes in the fish assemblages. Together, 45 fish taxa were detected, with substantial compositional variations between seasons. The number of detected species typically dropped upon entering the canal but remained relatively constant along the canal's length. Spatial variations in fish assemblages were generally dominated by the turnover component over nestedness, and a positive spatial autocorrelation of qualitative assemblage composition was detected within 80 km in all seasons. Furthermore, several functional traits, such as smaller body size, invertivorous diet, rheophilic living, and lithophilic and demersal spawning, were positive predictors of fish presence along the length of the canal and they may boost species chances of introduction to the recipient areas. Our results provide crucial information for ecological management of diversion projects and have key implications for modelling and predicting foreign species invasion through water transfers.

Root perforating internal replacement resorption: a case report clinical with 10-year follow-up

This study aims to report a root perforating internal replacement resorption treated and followed up for ten years. A 19-years female showed in periapical tomography enlargement of the entire length of the root canal of tooth 11. The cone-beam computed tomography (CBCT) showed a hypodense area with jagged edges involving the pulp cavity space and communication with the periodontium. After being accessed and prepared, the canal and its resorption defect were obturated with mineral trioxide aggregate. The cervical third was sealed with glass ionomer, and the tooth was restored with composite resin. Ten years later, the tomography showed intact root canal filling and periapical and periodontal injury absence. The use of repair cement for root canal obturation with perforating internal replacement resorption is an alternative for these cases, being fundamental to have a clinical, radiographic and tomographic follow-up to evaluate the treatment success.

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.

DETERMINATION OF MORPHOMETRY AND VOLUME OF THE INTERNAL AUDITORY CANAL

OBJECTIVE: The internal auditory canal (IAC) also known as internal acoustic meatus is a bone channel that connects the internal ear to the posterior cranial fossa. The mean length is approximately 1 cm. The edge of the IAC is called internal acoustic pore (IAP), and the edge of this aperture is blunt and rounded. Important formations such as facial nerve, vestibulocochlear nerve, labyrinth artery and labyrinth vein pass through the IAC. In addition, on the precise determination of the morphometry in surgical interventions on the temporal lobe, MAI is vital. Therefore, in this study, it was aimed to determine the morphometry and volume of MAI.MATERIAL AND METHODS: The study was carried out on the CT images of 210 individuals randomly from the normal population between the ages of 10-90. Morphometric measurements of IAC (lateral angle (LA), canal length, anteroposterior (AP), diameter of IAP, distance from IAP to vestibular aqueduct (VA)) were performed. In addition, the shape and volume of IAC was determined in this study. Cases were divided into 7 different subgroups, 10-14, 15-20, 21-30, 31-40, 41-50, 51-60 and 61 years old, depending on their age.RESULTS: In this study, CT images of 210 patients were analyzed. The mean length of the MAI was 9.5±1.6mm, the AP diameter was 6.3±1.5mm, the distance from the entrance part to the VA was 15.1±6.64mm, the volume was 290±120mm3, and the LA was 50±14º.CONCLUSIONS: When the outcome data were compared by gender, it was found statistically significant that the right AP diameter was higher in men, the length of the right MAI and both sides LA were higher in women. In addition, when the volumes of MAI were compared by age groups, it was determined that the 10-14 age group was smaller than the other age groups.

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.

Histological evaluation of ProRoot mineral trioxide aggregate and Cold ceramic as root-end filling materials in animal models

Background: This study aimed to evaluate the reaction of the periapical tissue to Cold ceramic and mineral trioxide aggregate (MTA) following periapical endodontic surgery.Materials and Methods: In this experimental study, a total of 12 mandibular first, second, and third premolars of two male dogs were selected. All procedures were performed under general anesthesia. The access cavities were prepared, and the length of canals was determined. Root canal treatment was performed. A week later, periradicular surgery was performed. After osteotomy, 3 mm of the root end was cut. Then, a 3-mm cavity was created by an ultrasonic. The teeth were randomly divided into two groups (n = 12). The root-end cavities were filled with MTA in the first group and with Cold ceramic in the second group. After 4 months, the animals were scarified. Histological evaluation of the periapical tissues was performed. Data were analyzed using SPSS 22 and Chi-square test and P = 0.05.Results: The findings showed 87.5% and 58.3% cementum formation in MTA and Cold ceramic groups, respectively, indicating a significant difference (P < 0.001). In addition, the results showed 91.7% and 83.3% bone formation in MTA and Cold ceramic groups, respectively, but the difference was not statistically significant (P = 0.6). Furthermore, the findings revealed 87.5% and 58.3% periodontal ligament (PDL) formation in MTA and Cold ceramic groups, respectively (P = 0.05).Conclusion: Cold ceramic was able to induce the regeneration of cementum, bone, and PDL; hence, it can be considered as a biocompatible root-end filling material in endodontic surgery.

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

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). The aim of this study was to compare three methods of WL determination to the actual visualization of the apical constriction (AC). 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. 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. The EAL provided more reliable and accurate WL measurements for single-rooted teeth among Ghanaians, compared to digital radiography and tactile methods.

Comparative evaluation of accuracy of different generations of electronic apex locator in determining the correct working length: A systematic review and meta-analysis

ABSTRACT Aim: Different approaches are used to determine the working length of the root canal. The current and most widely researched are the electronic apex locators (EALs). Since the early apex locators were developed in 1942, several generations had their qualities and shortcomings developed. Thus, a comparative evaluation of the accuracy of different generations of EALs in determining the correct working length: Systemic review and meta-analysis to analyze individual studies quantitively and draw conclusions on the best generation of apex locator currently used. Materials and Methods: A comprehensive search was conducted on different electronic databases and by manual search. Studies comparing third and fifth generations with fourth-generation apex locators were subject to strict inclusion criteria followed by data extraction and meta-analysis. Results: Following the meta-analysis, the accuracy is fifth&gt;fourth&gt;third generation of apex locators. Conclusion: Analysis of individual studies quantitatively will give a better understanding of which devices to use to accurately determine the working length.

Comparative evaluation of the accuracy of Propex PixiTM and CanalProTM electronic apex locators in primary anterior teeth

Aim: To evaluate and compare in vitro, the accuracy of two different electronic apex locators, i.e., Propex PixiTM and CanalProTM in primary anterior teeth. Methodology: A total of 60 primary teeth sample has been selected using a convenience sampling method. Samples were divided into two experimental groups in which, Group 1 belong to Propex PixiTM apex locator, and Group 2 CanalProTM. The mean values with standard deviations of electronic working length by using Propex PixiTM and CanalProTM with that of stereomicroscopic actual working length were calculated and compared Results: There was statistically significant difference between values obtained by the two electronic apex locators and actual length Conclusion: A strong correlation was seen between the two electronic methods and AL and also in between the two EALs, showing the possibility of their use to measure the root canal length.

Prediction of accessory canals on the apical third of mandibular second molar based on micro-computed tomography.

The aim of this study was to investigate the anatomical factors influencing the incidence of accessory canals (ACs) in the apical third of the mandibular second molar in Chinese population. Micro-CT was performed on 86 root canals. The five possible factors influencing the incidence of ACs in the apical third were named X1 to X5. These factors were the canal length of the apical third, fused roots, location of apical foramen, curvature of the root canals, and complexity of the canals. Statistical analysis was performed by the least absolute shrinkage and selection operator, receiver operating characteristic curve, and the χ2 test (α = 0.05). The selected variables in the least absolute shrinkage and selection operator regression model were fused roots and complex root canals. The area under the curve was 0.737, indicating that the model had a certain predictive ability. ACs were mainly distributed in the buccal wall and mesial wall of root canals in the apical third of molars (p < 0.05). For Chinese population, fused roots and complex root canals are anatomical factors influencing ACs in the apical one-third of mandibular second molars, and the ACs mainly occur in the buccal wall and mesial wall of the root canal.

COMPARISON OF THE METHOD OF ELECTROMETRIC DETERMINATION OF ROOT CANAL PARAMETERS AND THE METHOD OF THRESHOLD SEGMENTATION OF RADIOGRAPHS

The subject matter of the article is X-ray images of teeth during endodontic operations. The goal of the work is to compare the developed method of segmentation of the radiograph to determine the length of the root canal with the electrometric and mathematical methods in practice. The article uses the following methods: principles of endodontic preparation of teeth; methods of determining the working length of the root canal (radiological, electrometric); threshold segmentation method; method of segmentation of bone structures on tomographic images. The following results were obtained: the existing methods of determining the working length of the root canal were analyzed, the main advantages and disadvantages of each method were highlighted. The mathematical method is fast, but inaccurate and can only serve as a preliminary estimate. Electrometric is the most accurate, but has very strict requirements for measurement in the area of canal moisture, as well as invasiveness of the method has a number of disadvantages. Radiological is the most promising for research because of its painlessness to the patient, low radiation dose during intraoral radiography and the possibility of using image processing algorithms to refine the measurement results. This work formulated principles for segmentation and extraction of tooth contours on the X-ray image to determine working length and conducted practical studies to compare all methods of analysis. Conclusions. The application of the electrometric length determination method gives the most accurate result, but the segmentation of the radiograph allows the doctor to obtain additional information about the architectonics of the root canal. As well as the possibility of using image processing such as segmentation, contour extraction and automatic determination of the apical constriction zone make this method the most perspective. The most optimal is the combination of these two methods in practice, which requires additional research.

Overview of instrumentation used in endodontics

The fundamentals of root canal therapy include thorough cleaning, suitable shape, and total root canal filling. There are numerous tools at our disposal to help us achieve these goals. A complicated range of files, filling techniques, and modern materials have been designed to speed up the process, increase its dependability, and enable the clinician to properly treat challenging patients and intricate anatomies. Hand instruments include barbed broaches, reamers, and files such as K-file, K-flex file, Flexofile, and Hedstrom files. Nickel-titanium alloys have been used to replace stainless steel in the production of endodontic equipment. Compared to stainless steel tools, these lead to more straightening of canal curvature, centering, tapering, and leading to a superior preparation. In an effort to speed up preparation of canals and lessen operator fatigue, a wide variety of electric power-run tools have been created like reciprocating handpieces, rotary NiTi files and handpieces. Accurate root canal length measurement is crucial to the effectiveness of root canal therapy. Radiography and the application of an electronic apex locator are the two methods used most frequently to confirm canal length. Instruments needed for filling canals are dependent on the procedure chosen to fill the root canal. Hand or finger spreader with a pointed tip are used in lateral condensation; hand or finger pluggers with blunt, flat ends are employed in vertical condensation; thermomechanical compaction uses an engine-powered compactor, thermoplasticized injectable gutta-percha and gutta-percha carrier devices. Careful use of canal preparation, sterilization, and obturation techniques, together with the appropriate instrument selection and use, can significantly increase the likelihood that endodontic procedures will be successful.