An evaluation of the Apex Locator Endocater

The purpose of this study was to relate the relationship of the apical constriction to the anatomical apex and to determine the ability of the Endocater (Hygenic Corp., Akron, OH), using commercially bonded coated probes to locate the position of the apical constriction, in permanent teeth that were intact and had not been subjected to previous endodontic manipulation. Using local anesthesia and rubber dam isolation, conventional access cavities were prepared at ultra high speed with water coolant in teeth treatment planned for extraction. The Endocater was used to determine the working length. The probes were sealed in place with autopolymerizing composite resin and the teeth extracted. The teeth were sectioned buccolingually, and the position of the probe in relation to the anatomical apex and apical constriction was measured with the use of an ocular microscope. In 17.1% of the canals, the probes bound in the coronal portion of the canals and would not reach the apical portion of the root. In those teeth in which the probes reached the apical portion of the root, the Endocater was able to locate the apical constriction within 0.5 mm in 93.4% of the canals.     

Raypex 5根尖定位仪临床应用的准确性观察分析

目的：观察Raypex 5在临床应用中测量根管工作长度的准确性及影响因素。方法：共收集342例患者的903个根管,随机分为实验组和对照组。实验组458个根管采用Raypex 5测量根管工作长度。对照组445个根管,按手感法测量根管工作长度,拍摄X线片,分析比较,研究其准确性及影响因素。结果：在X线片上恰填范围内,实验组准确率达94.32%,对照组75.06%。电测法与手感法的准确率比较有显著性差异（P〈0.01）。牙髓活力,根尖骨质破坏状况,龋洞类型,牙位,牙齿形态,根管数目对Raypex 5测量根管工作长度的准确性无明显影响。结论：根尖定位仪Raypex 5能较为准确地测量根管工作长度,准确率比手感法高,值得临床推广使用。     

Clinical evaluation of the accuracy of the Evident RCM Mark II Apex Locator.

The accuracy of the Evident RCM Mark II in locating the apical foramen was evaluated in 37 human teeth scheduled for extraction. After extraction, the difference between the position of the apical foramen determined electronically and its real anatomical location was measured under a binocular microscope, using a micrometer mobile in x, y, and z coordinates. The results show that in 86% (n = 37) of the cases, an accurate location +/- 0.5 mm of the apical foramen was obtained.     

Micro-CT Study of the In Vivo Accuracy of a Wireless Electronic Apex Locator

IntroductionThis study aimed to compare the in vivo accuracy of Wirele-X and RootZX II electronic apex locators (EALs) in determining the position of the major foramen using micro–computed tomography (micro-CT) as the analytical tool.MethodsEleven vital teeth planned for extraction from 5 patients were used. After conventional access cavity preparation, root canals were flared and negotiated up to the apical third with sizes 08 and 10 K-files followed by irrigation with 2.5% NaOCl. K-type files were used to determine the working length of the selected canals using Root ZX II and Wirele-X apex locators until their numeric displays read “0.0.” After fixing the silicon stop to the file, teeth were extracted and imaged in a micro-CT device using a double-scan protocol. Image stacks, with and without the file in the root canal, were then co-registered and the measurement error calculated as the absolute difference between the tip of the file and the major foramen. Positive and negative values were recorded when the file tip was detected beyond or short of the major foramen, respectively. Accuracy was determined on stable measurements within ± 0.5 mm when the file tip did not extend beyond the major foramen. The χ² test was applied to compare the ability of the EALs to detect the position of the major foramen, and the t test for dependent variables was used to verify differences in the 2 measurements obtained in each tooth. Significance level was set at 5%.ResultsWithin a tolerance level of ± 0.5 mm, no significant differences were observed between the tested EALs regarding the absolute distance values (P = .82) or in their ability to detect the position of the major foramen (χ² = 0.2588; P = .6109). The accuracy of the Root ZX II and the Wirele-X apex locators within ± 0.5 mm were 81.8% and 90.9%, respectively.ConclusionsRoot ZX II and Wirele-X performed similarly regarding the in vivo detection of the major foramen. Using strict criteria, the accuracy of the Root ZX II and the Wirele-X apex locators were 81.8% and 90.9%, respectively.     

应用Neosono根尖定位仪测量根管工作长度的临床研究

目的：研究根尖定位仪Neosono测量根管工作长度的准确性。方法：选取250个需行根管治疗的单根管牙为研究对象,以插针拍X线片计算牙的长度,将电测法和手感法测得的根管工作长度与X线片法测得的牙的长度相比较来计算电测法和手感法的准确率,并进行统计学分析。结果：电测法的准确率是94．8％,手感法的准确率是74％,电测法的准确率高于手感法。结论：手感法的准确率较低,可起参考作用,电测法准确率较高,可作为根管工作长度的常规测量,必要时可用X线片法来确认。3种方法联合应用,能够满足临床要求。     

Root ZX根尖电测仪测定根管长度的准确性评价

目的：评价Root ZX根尖电测仪测定根管长度的准确性。方法：49颗(70个根管)根尖发育完全、因正畸需拔除的牙齿在局麻下，开髓、拔髓。Root ZX根尖电测仪测定根管长度，拔除后测定根管实长，比较二者的差异。分别以0．5mm、1．0mm、1．5mm误差评定测量结果的准确性。结果：体内测量平均根管长度为20．81mm，体外测量根管实际长度为21．21mm。84．29％(59／70)测量值位于根管内，8．57％(6／70)恰好位于根尖孔，7．14％(5／70)超出根尖孔。以0．5mm为标准，准确率为64．29％，以1．0mm为标准，准确率为81．43％。若以1．5mm以内为可接受范围，则准确率为90％。结论：Root ZX根尖电测仪能较准确测定根管工作长度，提高根管治疗的质量和工作效率。但仍需和X线照片结合指导临床工作。     

Accuracy of 2 Endodontic Rotary Motors with Integrated Apex Locator

Introduction

The purpose of this study was to evaluate in vitro the efficacy of both the electronic apex locator (EAL) and auto apical reverse (AAR) functions of the endodontic motor MM Control (Micro-Mega, Besançon Cedex, France) compared with Root ZX II (J Morita, Tokyo, Japan).

牙髓状态对Neosono Co-pilot 根尖定位仪准确性的影响

目的 观察牙髓状态对Neosono Co-pilot根尖定位仪测量根管工作长度准确性的影响.方法 选择患牙201颗、根管375个,分为牙髓坏死组、牙髓失活组和活髓组,均采用Neosono Co-pilot 根尖定位仪和X线数字成像法测量根管工作长度,以后者评价前者的准确性,并比较各组间差异.结果 Neosono Co-pilot根尖定位仪测量根管工作长度的准确率在牙髓坏死组、牙髓失活组和活髓组分别为92.6%、91.7%、86.0%,3组间准确率差异无统计学意义(P＞0.05).结论 Neosono Co-pilot根尖定位仪对根管工作长度的测量准确性较高,且不受牙髓活力的影响.     

An Ex Vivo Comparison of Electronic Apex Locator Teaching Models

Introduction

This study aimed to develop a simple and inexpensive ex vivo model to teach students the use of electronic apex locators in a preclinical setting.

Methods

Using 27 extracted human teeth, the Raypex 5 (VDW, Munich, Germany) and Dentaport ZX (J. Morita Co, Kyoto, Japan) were tested in three different media (ie, alginate, sugar-free gelatin, and 0.9% sodium chloride solution). Working lengths determined by these models were compared with those obtained by digital radiography and direct visualization using a linear mixed modeling statistical approach.

Results

Raypex 5 exhibited a higher percentage of measurements accurate to ±0.5 mm and ±1.0 mm of the control across all three media in all tooth types. In multirooted teeth, alginate showed the highest accuracy.

Conclusions

The most accurate EAL/embedding medium combination was Raypex 5/alginate to both ±0.5 mm and ±1.0 mm of the control. The model tested in this study was accurate, easy to assemble, and cost-effective, making it suitable for teaching purposes.     

Evaluation of the Raypex 5 and the Mini Apex Locator: an in vivo study

Introduction

The purpose of this study was to compare the accuracy in vivo of 2 electronic apex locators (EALs), the Raypex 5 and the Mini Apex Locator.

Methods

The working length (WL) was determined electronically for 40 human root canals by using a K-file and 1 of the 2 EALs. The files were fixed at the WL, and the teeth were extracted. The apical 4 mm of each canal was trimmed to expose the file tip. The samples were observed under a scanning electron microscope, and the distance from the file tip to the point 0.5 mm coronal to the major foramen (the final WL) was measured. The data were analyzed by using Student t test, and significance was set at P < .05.

Results

No statistically significant differences were found between the Raypex 5 and the Mini Apex Locator devices. The mean distance from the final WL to the file tip was 0.174 ± 0.38 mm for the Raypex 5 and 0.286 ± 0.30 mm for the Mini Apex Locator. In determining the final WL, the Raypex 5 was accurate 75% of the time to ±0.5 mm and 100% of the time to ±1 mm, whereas the Mini Apex Locator was accurate 77.8% of the time to ±0.5 mm and 100% of the time to ±1 mm.

Conclusions

Under the in vivo conditions of this study, no statistically significant differences were observed between the Raypex 5 and the Mini Apex Locator EALs.     

Effect of Working Length Measurement by Electronic Apex Locator or Digital Radiography on Postoperative Pain: A Randomized Clinical Trial

Introduction

The aim of this study was to evaluate the effect of working length determination methods, electronic apex locator and digital radiography, on postoperative pain.

Methods

Two hundred twenty patients with asymptomatic single-rooted vital teeth were randomly assigned to 2 groups according to the method used for working length determination, the radiographic group and the electronic apex locator group. After working length determination, chemomechanical preparation was performed in a crown-down technique with ProTaper instruments. A master cone radiograph was taken. Canals were obturated with gutta-percha and sealer by using a lateral compaction technique. Postoperative pain was assessed after 4, 6, 12, 24, and 48 hours by using a 4-point pain intensity scale. In addition, patients were asked to record the number of days necessary to achieve complete pain resolution.

Results

Postoperative pain during the 4-hour to 48-hour interval studied was not significantly different (P > .05) between groups. The mean times for pain dissipation in the radiographic and electronic apex locator groups were 3.37 ± 2.79 and 3.88 ± 3.34 days, respectively. The difference between groups was not statistically significant (P > .05).

Conclusions

There is no difference in postoperative pain between working length measurement methods by using an electronic apex locator or digital radiography. The reduced exposure to radiation by using apex locator may be a factor that influences a dentist's decision to choose the electronic apex locator over radiography.     

2种根尖定位仪诊断牙根纵裂的临床研究

目的研究RootZX和ProPex根尖定位仪用于诊断牙根纵裂的可靠性与准确性。方法分别用RootZX和ProPex根尖定位仪测量临床上疑为牙根纵裂患牙的根管工作长度,按照测量长度插入诊断丝,拍摄X线片。正常根管中诊断丝止于距根尖孔0．5～1．0mm范围内,诊断丝终止位置距根尖孔长度为牙根长度1／3及以上者初步诊断为牙根纵裂。拔除患牙后测量根管实际长度与纵裂根管长度,与电测长度进行比较。结果临床疑似牙根纵裂患牙48颗,经根尖定位仪联合X线检查初步诊断牙根纵裂48颗,拔牙后确诊牙根纵裂42颗,确诊率为87．5％。42颗牙根纵裂患牙中,RootZX电测长度平均值为（8．78±0．87）mm;ProPex电测平均值为（8．73±0．85）mm;根管实际长度平均值为（19．26±0．82）mm;纵裂根管长度平均值为（8．61±0．78）mm。RootZX和ProPex2种根尖定位仪的电测长度皆小于根管实际长度（P〈0．001）;RootZX电测值、ProPex电测值、纵裂根管长度之间差异无统计学意义（F=1．342,P〉0．05）。结论根尖定位仪有助于牙根纵裂的临床诊断。     

根管扩大程度影响根管长度电测仪准确性的研究

目的 探讨根管扩大程度对根管长度电测仪准确性的影响.方法 收集根尖发育完全、根管通畅的离体牙45颗,用回旋手机和ISO标准型不锈钢根管锉扩大根管,测量扩大前、常规扩大后和过度扩大后的电测长度、实测长度,并进行统计分析.结果 ①电测长度与实测长度误差为0时,根管扩大前、常规扩大后、过度扩大后准确率为97.06%、 90.91%、 80.00%;误差在±0.5 mm时,根管扩大前、常规扩大后、过度扩大后准确率为98.53%、95.45%及86.67%;根管扩大前和常规扩大后差异无统计学意义,扩大前和过度扩大后差异有统计学意义,常规扩大和过度扩大后差异无统计学意义.②后牙根管过度扩大后实测长度短于原始实测长度的发生率达40.38%,与常规扩大组发生率3.45%相比,差异有统计学意义.结论 NeosonoTM电测仪准确性随根管及根尖孔的扩大而呈现下降趋势;ISO标准型不锈钢根管锉常规扩大根管对电测仪准确性影响不大,过度扩大会显著降低电测仪的准确性.     

根管干湿状态对电测根管长度准确性的影响

目的评价根管干湿状态对ROOT ZX测定根管工作长度的准确性的影响。方法21颗根尖发育完成的单根管牙,用ROOT ZX根管长度电测仪分别测量根管在干、湿状态时的根管工作长度,与拔牙后所测实际值比较,并进行统计学分析。结果根管干、湿状态下ROOT ZX的电测值与实际值间的差异均无统计学意义(P>0.05)。结论对于根尖孔已发育完成的患牙,根管干、湿状态对ROOT ZX测量根管工作长度的准确性无影响。     

牙髓状态对Root ZX根尖电测仪准确性的影响

目的:评价牙髓状态对Root ZX根尖电测仪测定根管长度准确性的影响。方法:选择根尖发育完全,因正畸、牙周疾病及义齿修复需拔除的单根牙,利用活力检测仪测定牙髓状态,获得活髓牙及死髓牙各31例。开髓,分别在保存牙髓及拔除牙髓后,Root ZX根尖电测仪测定根管长度,然后拔除该牙测定根管实长,比较牙髓存在前后测量长度与实际长度间的差别。结果:活髓牙牙髓存在时根管测量长度为(19.95±1.77)mm,拔髓后测量长度为(20.04±1.79)mm,拔牙后根管实际长度为(20.39±2.01)mm。死髓牙拔髓前根管测量长度为(19.72±1.77)mm,拔髓后测量长度为(19.80±1.76)mm,拔牙后根管实际长度为(20.12±1.74)mm。拔髓前/后与实际长度比较均没有显著差异(P>0.05)。以0.5 mm准确标准,活髓牙拔髓前/后准确率分别是61.29%和64.52%,死髓牙拔髓前/后准确率分别是64.52%和67.74%。拔髓前/后及活髓/死髓牙准确率均无显著差异(P>0.05)。结论:牙髓状态及牙髓存在与否对Root ZX根尖电测仪测定根管工作长度的准确性没有明显的影响。     

An In Vivo Comparison of the Root ZX II,the Apex NRG XFR,and Mini Apex Locator by Using Rotary Nickel-Titanium Files

IntroductionThe purpose of this study was to compare the accuracy of working length (WL) measurements by using the Root ZX II, Apex NRG XFR, and Mini Apex Locator with rotary nickel-titanium (NiTi) instruments.MethodsTwenty-eight teeth had their WLs determined with each electronic apex locator (EAL) by using 0.04 taper ProFiles sizes 40–20 in a crown-down technique until WL was reached. Four control teeth had their WL determined by using stainless steel hand files. The files were cemented at WL, and the teeth were extracted. The apical 4 mm of each root was shaved to the apical constriction, exposing the file. Photographs were taken under 15× and 30× magnification and projected at 360× and 720× for evaluation.ResultsThe accuracy of the Root ZX II, Apex NRG XFR, and Mini Apex Locator in locating the minor diameter within ±0.5 mm was 50%, 46.43%, and 39.29%, respectively. There was no statistically significant difference between the EALs in locating the minor diameter. The determination of WL by using hand files in the control teeth was more accurate.ConclusionsThe Root ZX II, Apex NRG XFR, and Mini Apex Locator used with rotary NiTi files were able to locate the apical constriction within ±0.5 mm only 50% or less of the time.     

Ex vivo accuracy of three electronic apex locators: Root ZX, Elements Diagnostic Unit and Apex Locator and ProPex

AIM: To compare ex vivo the accuracy of three electronic apex locators (EALs): Root ZX, Elements Diagnostic Unit and Apex Locator and ProPex. METHODOLOGY: Electronic working length determination was carried out in 40 extracted teeth using an ex vivo model. After access preparation, a first operator determined the reference length (AL) for each tooth under a 30x stereomicroscope using the apical constriction as the apical landmark. All teeth were then measured with each EAL and the results obtained were compared with the corresponding AL. The AL was subtracted from the electronically determined distance. The measurements exceeding the AL were recorded as positive (long) and the measurements short of the AL were recorded as negative. Data were analyzed using the Friedman Test and Tukey multiple range test for nonparametric correlation amongst groups. Statistical significance was considered at P < 0.05. RESULTS: Comparing the differences between measurements obtained with the three EALs and those obtained with the stereomicroscope, the percentage of measurements within +/-0.5 mm of the AL was 97.37% (84.22% within 0.5 mm short of AL) for the Root ZX, 94.28% (88.57% within 0.5 mm short of AL) for the Elements and 100% (35.9% within 0.5 mm short of AL) for the ProPex. The mean difference between the AL and the lengths measured by the Root ZX, the Elements and the ProPex were, respectively, -0.157 +/- 0.228, -0.103 +/- 0.359 and 0.307 +/- 0.271 mm. CONCLUSIONS: The results of the present study confirm that the EALs determined the canal length within +/-0.5 mm from the apical constriction in the majority of cases. The majority of the ProPex readings were long.     

Clinical Efficacy of Electronic Apex Locators: Systematic Review

Introduction

Apical constriction has been proposed as the most appropriate apical limit for the endodontic working length. Despite being the most used, some limitations are attributed to the radiographic method of working length determination. It lacks precision because it is based on the average position of the apical constriction. The electronic apex locators have been presented as an alternative to the odontometry performed by radiography. These devices detect the transition of the pulp to the periodontal tissue, which is anatomically very close to the apical constriction and may perform with improved accuracy.

Methods

A systematic review was performed to compare the radiographic and electronic methods. Clinical studies that compared both methods were searched for on 7 electronic databases, a manual search was performed on the bibliography of articles collected on the electronic databases, and the authors were contacted to ask for references of more research not detected on the electronic and manual search.

Results

Twenty-one articles were selected. The majority were comparative or evaluation studies, and very few clinical studies comparing both methods are available. Several methodological limitations are present on the collected articles and debated in this review.

Conclusions

Although the available scientific evidence base is short and at considerable risk of bias, it is still possible to conclude that the apical locator reduces the patient radiation exposure and also that the electronic method may perform better on the working length determination. At least one radiographic control should be performed to detect possible errors of the electronic devices.