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.

Clinical Accuracy and Precision of 3 Multifrequency Electronic Apex Locators Assessed through Micro-Computed Tomographic Imaging.

INTRODUCTION: This study aimed to compare the in vivo accuracy and precision of 3 electronic apex locators (EALs) in determining the position of the major foramen using micro-computed tomographic (micro-CT) technology. METHODS: After access preparation of 23 necrotic or vital teeth from 5 patients, canals were negotiated, and hand files were used to determine the position of the foramen with 3 EALs: Propex Pixi (Dentsply Maillefer, Ballaigues, Switzerland), Woodpex III (Woodpecker Medical Instrument Co, Guilin, China), and Root ZX II (J Morita, Tokyo, Japan). After fixing the silicon stop to the file, teeth were extracted and scanned in a micro-CT device with and without the instrument inserted into the canal. Data sets were coregistered, and the accuracy and precision of the EALs were determined at a tolerance level of ±0.5 mm by measuring the distance from the tip of the instruments to a tangential line crossing the margins of the foramen. Statistical comparisons were performed using Friedman with post hoc related samples sign and Spearman tests (α = 5%). RESULTS: A significant difference was detected comparing the accuracy of Root ZX II (100%), Woodpex III (86.96%), and Propex Pixi (52.17%) (P < .05). There was a lack of significance in the relationship between the pulp status and the accuracy of the tested EALs (P > .05). Propex Pixi was significantly less precise than Root ZX II (P < .05), whereas no difference was found between Woodpex III and Root ZX II or Propex Pixi (P > .05). CONCLUSIONS: EALs presented similar precision, but Woodpex III and Root ZX II showed better accuracy to determine the position of the apical major foramen than Propex Pixi.

Are electronic apex locators accurate in determining working length in primary teeth pulpectomies? A systematic review and meta-analysis of clinical studies.

BACKGROUND: The lack of a well-defined apical constriction in primary teeth raises concerns regarding the accuracy of electronic apex locators (EALs) for measuring working length. OBJECTIVES: To evaluate the accuracy of EALs in determining working length in primary teeth pulpectomies. METHODS: Two reviewers searched ten databases up to September 2021. Clinical studies evaluating the accuracy of the electronic measurement of working length in primary teeth pulpectomies were included. Studies without a comparison group, with samples smaller than ten root canals, and that did not use a multiple frequency EAL were excluded. A meta-analysis was conducted to assess the paired differences in mean lengths between measurements obtained by electronic and comparative methods. In addition, a meta-analysis of proportion was applied according to the level of difference between the measures. The risk of bias and applicability of the studies were assessed using the QUADAS-2 tool. The certainty of evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: Twenty-nine studies were included in the qualitative analysis and twenty-three in the quantitative analysis. The methods of comparison for the electronic measurement were the radiographic method, radiovisiographic, scanning electron microscopy, and direct visualization. The meta-analysis showed that the electronic measurement tends to be shorter than radiographic measurement, while the other methods showed no difference. The proportion analysis showed a higher pooled proportion of difference values between electronic and comparative measurements within -0.5 to +0.5 mm (69.31%). The certainty of the evidence suggested very low confidence in estimating the outcome. DISCUSSION: The results of this review denote a good performance of the EALs in determining working length in primary teeth pulpectomies. However, these results are based on clinical studies with low methodological quality and high heterogeneity, which require careful interpretation for clinical practice. CONCLUSIONS: Although the results suggest acceptable accuracy of EALs in determining working length in primary teeth pulpectomies, the low quality of the included studies and the very low certainty of the evidence require clinicians to interpret these results with caution. More robust evidence is required to support that these devices are accurate for primary teeth. REGISTRATION: CRD42021277414 (PROSPERO).

Accuracy of Four Apex Locators in Premolars with Root Resorption: An In vitro Study.

Introduction: The aim of the present in vitro study was to compare the accuracy of the working length measurements of four foramen locators: Root ZX mini, Raypex 6, Woodpex III and Propex Pixi in uniradicular premolars with simulated root resorption. Materials and Methods: For this study, 30 single-rooted permanent premolars were selected. The samples were divided into two groups: 15 teeth with simulated external root resorption and 15 teeth with internal resorption. Each sample was immersed in containers with alginate covering only the root part. Measurements were acquired from the four foramen locators and compared with the working length measurements that have been previously obtained with the direct visual technique and the use of a Digital USB Microscope under 5×. Next, the Shapiro-Wilk normality test was applied. The ANOVA test and t-test for related samples were performed, in order to analyze the measurements obtained. Results: In the teeth with external resorption, no statistically significant differences in the measurements were obtained with Raypex 6 and Propex Pixi foramen locators, but there were statistically significant differences with Root ZX mini and Woodpex III Root Zx mini [Root Zx mini (P=0.040) and Woodpex III (P=0.000)]. On the other hand, in the samples with internal root resorption, there were no statistically significant differences in measurements with the Root ZX mini, Propex Pixi and Raypex 6 foramen locators. However, there were significant differences with Woodpex III. Conclusions: Based on this in vitro study, Raypex 6 had the highest accuracy in premolars with simulated external resorption and Root ZX mini was the most accurate in teeth with simulated internal resorption. Furthermore, external root resorption affects the accuracy of foramen locators more than internal resorption.

Effect of Materials For Interim Restoration on Estimation of Working Length Using Electronic Apex Locator: in vitro Study / Efecto de Materiales Para Restauración Intermedia sobre la Estimación de la Longitud de Trabajo Endodóntico Utilizando Localizador Electrónico de Foramen: Estudio in vitro

ABSTRACT: The aim of this in vitro study was to evaluate measurement accordance using an electronic apex locator for estimation of working length in endodontics when different restorative materials for interim crown restoration are utilized. For this study, 13 single-rooted premolars with endodontic occlusal access cavity were prepared. To establish the working length of each tooth, these were mounted in alginate and with the help of an electronic foramen locator and endodontic file K-file # 15, the working length was established. This length was later compared to the estimated working lengths using different intermediate restoration materials. These materials were: Superior Chemfil, Ketac ™ Molar Easymix and Filtek z350 resin. In the electronic measurements, an acceptable tolerance range of variation up to ± 0.5 mm was considered. Highest discrepancies were considered erroneous. For these measurements, central tendency and dispersion were analyzed. The Bland-Altman method was used, and the ANOVA test with a significance level of p <0,05 for statistic difference. Regarding measurements' acceptability and the type of interim restoration material utilized, 7 were acceptable, and 6 were unacceptable for ChemFil Superior, 12 were acceptable and 1 unacceptable for Ketac™ Molar Easymix, and 11 were acceptable and 2 were unacceptable for Filtek Z350 composite resin. The average difference between all electronic measurements was 0.29 (± 0.44). Chemfill Superior showed the most prominent variation between measurements 0.58 (± 0.45). When using an electronic apex locator, measurements showed statistically significant differences depending on the interim restoration material of choice (p<0.05). In conclusion, the measurement accordance using electronic apex locator to estimation the working length is higher, however the electronic estimation of working length can be significatively affected by the material chosen for interim temporary restoration.

RESUMEN: El objetivo de este estudio in vitro, fue evaluar la concordancia de las estimaciones de longitud de trabajo mediante localizador electrónico de foramen, utilizando diferentes materiales de restauración intermedia coronaria. Para tales fines fueron preparados 13 premolares uniradiculares con cavidad de acceso oclusal endodóntico. Para establecer la a longitud de trabajo de cada diente, estos fueron montados en alginato y con la ayuda de un localizador electrónico de foramen y lima de endodoncia K-file #15 fue establecida la longitud de trabajo. Esta longitud fue comparada posteriormente con las longitudes de trabajo estimadas utilizando diferentes materiales de restauración in- termedia. Estos materiales fueron: Chemfil superior, Ketac™ Molar Easymix y resina Filtek z350. En las mediciones electrónicas, se consideró un rango de tolerancia aceptable de variación hasta ± 0,5 mm. Las discrepancias mayores se consideraron erróneas. Se calcularon medidas de tendencia central y la dispersión. Se utilizó el método de Bland- Altman y la prueba ANOVA con un nivel de significancia de p <0,05. Con respecto a la aceptabilidad de las mediciones y el tipo de material de restauración intermedia, 7 fueron aceptables y 6 fueron inaceptables para ChemFil Superior, 12 fueron aceptables y 1 inaceptable para Ketac ™ Molar Easymix, y 11 fueron aceptables y 2 fueron inaceptables para el compuesto Filtek Z350 resina. La diferencia promedio entre todas las mediciones electrónicas fue de 0,29 (± 0,44). Chemfil Superior mostró la mayor variación entre medicio- nes 0,58 (± 0,45). Las mediciones mostraron diferencias estadísticamente significativas dependiendo del material de restauración intermedio elegido (p <0,05). En conclusión, la concordancia en la estimación de la longitud de trabajo usando localizador electrónico de foramen es alta, sin embargo, puede verse afectada significativamente por el material de obturación intermedio.

The influence of periapical lesions on the repeatability of two electronic apex locators in vivo.

OBJECTIVES: To determine the influence of periapical lesions on the repeatability of two electronic apex locators (EALs), Root ZX II, and RomiApex A-15, in maxillary anterior teeth, in vivo. MATERIALS AND METHODS: After approval by the local ethics committee, 43 maxillary anterior teeth scheduled for root canal therapy were assigned to two groups. The periapical lesion (PAL) group included 21 teeth with necrotic pulps and radiographically visible periapical lesion, and the normal periapex (NPA) group consisted of 22 teeth with vital pulps and no periapical lesion. In each canal, Root ZX II and RomiApex A-15 were used to determine working length defined as the "zero" reading on the display. Two consecutive measurements were performed with each EAL on each tooth and a second operator measured the endodontic file with a digital caliper without knowledge of the EAL being used or the tooth diagnosis. The absolute value of the difference between the first and second measurement (measurement pairs) was calculated. Repeatability was evaluated by the Bland-Altman method, and an aligned ranks transformation ANOVA was conducted to compare the EALs. RESULTS: The median absolute difference between measurement pairs was significantly lower (p < 0.001) and the limits of agreement were narrower in the NPA group. Among the EALs, median absolute differences were significantly smaller for Root ZX (p < 0.001). CONCLUSIONS: Measurements were more repeatable when no periapical lesion was present. Root ZX showed better repeatability than RomiApex. CLINICAL RELEVANCE: Periapical lesions seem to influence successive in vivo measurements with EALs.

Accuracy of electronic apical functions of a new integrated motor compared to the visual control of the working length-an ex vivo study.

OBJECTIVES: To evaluate ex vivo the efficacy of the integrated motor Tri Auto ZX2 in controlling the apical extent of preparation compared to conventional visual control (CVC) of the working length (WL). MATERIALS AND METHODS: Eighty standardized mandibular premolars were divided into five groups (n = 16). In the CVC group, instruments were used in continuous rotation (CR) and visual control performed by means of rubber stoppers. For each of the remaining groups, it was assigned a combination of a motion (CR or optimal torque reverse (OTR)), and an apical function (Auto Apical Reverse (AAR) or Optimum Apical Stop (OAS)). Root canals were prepared using the apical functions at 0.5 mark using an alginate model. Difference between the final WL and the actual length post-instrumentation was calculated. Data were analyzed statistically with the significance set at 5% (ANOVA, Tukey HSD). RESULTS: There was no difference in the mean WL among the groups, except between the CR combined to OAS compared to CVC (P > 0.05). Although CVC resulted in two cases beyond the foramen, no significant difference was found among the groups when comparing the distributions of measurements (P > 0.05). CONCLUSIONS: All combinations of motion and apical control functions of Tri Auto ZX2 provided an adequate apical limit ex vivo, similar to the visual control using rubber stoppers. CLINICAL RELEVANCE: TriAuto ZX2 was efficient to control the apical extent of preparation dispensing the need for calibrating the files, regardless of the different settings. This motor might potentially prevent over-instrumentation by continuously monitoring the apical limit.

In Vivo Evaluation of 3 Electronic Apex Locators: Root ZX Mini, Apex ID, and Propex Pixi.

INTRODUCTION: The aim of this in vivo study was to compare the accuracy of 3 electronic apex locators (EALs) (Root ZX mini [J Morita Corp, Tokyo, Japan], Apex ID [SybronEndo, Glendora, CA], and Propex Pixi [Dentsply Maillefer, Ballaigues, Switzerland]) to determine the working length. METHODS: Thirty single-rooted human teeth that were scheduled for extraction were selected for the study. Electronic measurements were performed with the 3 EALs. After the teeth had been extracted, a #10 K-file was used to determine the actual working length, which was established at 0.5 mm short of the major foramen. The data were statistically analyzed with analysis of variance (α = 0.05). RESULTS: No significant differences were found among the experimental groups (P > .05). The mean distance from the actual working length to the file tip was 0.163 ± 0.032 mm when Root ZX mini was used, 0.343 ± 0.032 mm for Propex Pixi , and 0.012 ± 0.008 mm for Apex ID. CONCLUSIONS: Under the in vivo conditions of this study, no statistically significant differences were observed among the 3 EALs.

Comparative evaluation of the effect of various irrigants and dry canal on electronic apex locators in locating simulated root perforations: an in vitro study / Avaliação comparativa do efeito de vários irrigantes e canal seco em localizadores apicais eletrônicos na localização de perfurações radiculares simuladas: um estudo in vitro

Objective: this study aimed to evaluate the effects of irrigants and dry canal on the accuracy of electronic apex locator (EAL) in locating simulated root perforations. Material and methods: twenty singlerooted, mandibular premolars were decoronated at CEJ, and the contents were removed with a barbed broach. The canals were instrumented up to a size of 15 K-file. The roots were artificially perforated at 4 mm from the anatomic apex. The actual length (AL) up to the perforation site was determined. The electronic length (EL) of perforations was obtained by Root ZX mini and iRoot in the dry canal and in the presence of 5.2% NaOCl, SmearOff, and 0.9% sodium chloride using a size 20 K-file. The differences between the EL and AL of the perforations were calculated. Statistical analyses using Friedman and Wilcoxon signed-rank tests were used to analyse the data with the level of significance set at p <0.05. Results: there were significant differences in different canal conditions with both Root ZX mini and i Root. Measurements in dry canals were significantly longer for both apex locators (p <0.05). Measurements with NaOCl were significantly shorter for both apex locators (p < 0.05). Both apex locators produced significantly accurate values for Saline and Smear OFF (p < 0.05). Conclusions: in this study, both Root ZX mini and i Root were affected by different canal conditions. The most accurate measurements were seen in the presence of saline and SmearOFF. (AU)

Objetivo: este estudo teve como objetivo avaliar os efeitos de irrigantes e canal seco na precisão do localizador apical eletrônico (EAL) em localizar perfurações radiculares simuladas. Material e métodos: vinte pré-molares inferiores unirradiculares tiveram suas coroas removidas na altura da JEC e o tecido pulpar removido com um extirpa nervos. Os canais foram instrumentados até a largura de uma lima k 15. As raízes foram perfuradas artificialmente a 4 mm do ápice anatômico. O comprimento real (AL) até o local da perfuração foi determinado. O comprimento eletrônico (EL) das perfurações foi obtido pelo Root ZX mini e iRoot no canal seco e na presença de 5,2% de NaOCl, SmearOff e 0,9% de cloreto de sódio usando uma lima K tamanho 20. As diferenças entre o EL e o AL das perfurações foram calculadas. Análises estatísticas, utilizando os testes de sinais por postos de Friedman e Wilcoxon, foram realizadas para analisar os dados com o nível de significância estabelecido em p < 0,05. Resultados: houve diferenças significativas nas diferentes condições do canal, tanto no Root ZX mini quanto no i Root. As medidas em canais secos foram significativamente maiores nos dois localizadores apicais (p < 0,05). As medidas com NaOCl foram significativamente mais curtas para os dois localizadores apicais (p<0,05). Ambos os localizadores apicais produziram valores significativamente precisos para Saline e Smear OFF (p < 0,05). Conclusões: neste estudo, tanto o Root ZX mini quanto o i Root foram afetados por diferentes condições do canal. As medidas mais precisa foram observadas na presença de soro fisiológico e SmearOFF. (AU)

Accuracy of Four Electronic Apex Locators During Root Canal Length Determination / Precisión de Cuatro Localizadores de Ápice en la Determinación de la Longitud de Trabajo

ABSTRACT: The apical limit of tooth roots for instrumentation and obturation is a controversial subject due to the high morphological complexity presented by the apical zone of the root. The development of electronic apex locators (EALs) has made working length (WL) determination more predictable, producing more accurate results; however, the interpretation mechanisms of different devices may affect measurements taken under different clinical conditions. One hundred premolars were used to compare the effectiveness of Propex II, Raypex 6, Propex Pixi and Root ZX II in locating the apical foramen (AF). No statistically significant differences were observed when the accuracy of measurement was compared between the different groups of EALs, however Root ZX II and Raypex 6 presented the best overall performance.

RESUMEN: El límite apical radicular para la instrumentación y obturación es un tema controversial, debido a la alta complejidad morfológica que presenta la zona apical de la raíz. El desarrollo de localizadores de ápice electrónicos (EALs) ha hecho la determinación de la longitud de trabajo (WL) más predecible y con resultados más precisos. Sin embargo, el mecanismo de interpretación de cada dispositivo puede afectar la determinación de las mediciones en diferentes condiciones clínicas. Cien premolares fueron utilizados para comparar la efectividad de Propex II, Raypex 6, Propex Pixi y Root ZX II en localizar el foramen apical (AF). No se observaron diferencias estadísticamente significativas cuando se comparó la precisión de medición entre los diferentes grupos de EALs, sin embargo, Root ZX II y Raypex 6 mostraron un mejor desempeño global.

The Accuracy of a New Cone-beam Computed Tomographic Software in the Preoperative Working Length Determination Ex Vivo.

INTRODUCTION: This study investigates the accuracy of 3D Endo software (Dentsply Sirona, Salzburg, Austria) to determine the working length when using preoperative cone-beam computed tomographic (CBCT) scans of extracted teeth, compared with conventional CBCT software and an electronic apex locator (EAL). METHODS: CBCT scans of 30 premolars were obtained. Using OnDemand3D software (Cybermed, Seoul, Korea), the measurement obtained from the coronal reference to the apical foramen (AF) was recorded as the conventional CBCT length. Then, using 3D Endo software (Dentsply Sirona), the suggested length (3D-SL) and the operator-adjusted length (3D-OL) were obtained. Teeth were accessed, and the actual length was measured. Finally, the teeth were embedded in alginate to obtain the electronic length (EL) using the EAL Root ZX (J Morita, Tokyo, Japan). The means of the absolute values and the percentages of distribution of the tested measurement methods were compared to the actual length. RESULTS: No difference was found regarding the mean measurements (analysis of variance, P > .05). All the CBCT measurements presented a high reliability (Dahlberg's formula). The measurements within a ±0.5-mm range from the AF were 86.6% for the 3D-SL, 80% for the 3D-OL and EL, and 73.3% for the CBCT length. The EL presented significantly fewer underestimated measurements (P < .05). The 3D-OL and 3D-SL presented significantly fewer measurements beyond the AF (P < .05). CONCLUSIONS: The preoperative working length determination using 3D Endo was reliable and similar to conventional CBCT software. However, the combined use of CBCT with an EAL is required to increase the accuracy in the location of the AF.

Influence of different sized files on the accuracy of two electronic apex locators.

The aim of this study was to evaluate the impact of different file sizes on the accuracy of two electronic apex locators (EALs). Thirty extracted human single-rooted permanent mandibular incisors were used. A #10 K-file was inserted in the root canal until its end could be observed (using a light microscope) through the apical foramen. One millimetre was subtracted to establish working length (WL). Electronic readings were performed using MiniApex Locator or Root ZX II, from #10 K-file to #130 K-file. Statistical analysis was performed by two-way anova and Tukey test (P ≤ 0.05). From #60 to #130 K-file, observed differences were noted between the values obtained with both EALs and WL (P ≤ 0.05). The MiniApex Locator showed increased means when measurements were made with #50 to #70 and with #120 (P = 0.008) and #130 (P = 0.005) K-files. File sizes influenced the accuracy of EALs - the greater the instrumentation size, the higher mean differences compared to WL.

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). METHODS: After cervical preflaring, the actual lengths (ALs) of 36 single-rooted teeth were obtained up to the apical foramen. The EAL measurements at the marks "APEX" and "0.5" of both devices were obtained using an alginate model. The teeth were divided randomly into 2 groups (n = 18), and root canal preparation was performed with rotary instruments using the AAR function (0.5 mark) of each motor. The length provided by the AAR was compared with the visual length after preparation (AL2). The differences between the electronic lengths and the respective visual measurements were assigned as negative for lower or positive when higher. The means of the absolute values and the percentages of distribution of the electronic measurements between devices were compared. RESULTS: There was no difference between the devices in terms of the means of the EAL measurements or AAR length (analysis of variance, P > .05). However, the EAL function of MM Control presented a greater percentage of measurements >1.01 mm longer than AL (chi-square, P < .01). The AAR function provided an acceptable apical limit in 83.3% of the cases for Root ZX and 77.8% of the cases for MM Control. CONCLUSIONS: The AAR function of both MM Control and Root ZX II provided an adequate apical limit of preparation in vitro. However, the use of only the EAL function of MM Control resulted in significantly more cases of overextended readings.

Evaluación de un modelo de capacitación preclínica en el uso de los localizadores electrónicos del foramen, por alumnos de grado de endodoncia / Evaluation of a preclinical training model of undergraduatestudents in the use of electronic foramen locatorsin endodontics

Objetivo: evaluar la capacitación y los resultados del uso de localizadores del foramen en un curso preclínico destinado a alumnos de grado de la Escuela de Odontología de la Universidad del Salvador / AsociaciónOdontológica Argentina, entre 2005 y 2016. Materiales y métodos: Se emplearon 2053 incisivos, caninos y premolares inferiores y superiores humanos extraídos. Los dientes se montaron de modo tal que sus raí-ces quedasen sumergidas en una solución salina, utilizando dos métodos: a) tubos de plástico, b) modelos que simulan la arcada dentaria. Se realizaron los accesos coronarios al conducto radicular de forma convencional y se prepararonlos tercios cervical y medio. Para determinar la longitud de trabajo, se introdujo una lima tipo K de calibre acorde con el conducto radicular, ajustando en ella el terminal del localizador electrónico del foramen. El terminal labial se sumergió en la misma solución salina en que se encontraban las raíces dentarias. En la mayoría de los dientes se empleó, parala determinación, la técnica de ingreso, y en los restantes, la de regreso. El nivel de penetración se estableció con la señal lumínica y/o sonora de 0,5. Se ajustó el tope del instrumento al borde de referencia y se obtuvo una imagen radiográfica periapical del diente evaluado. Se retiró el instrumento del conducto radicular y se midió desde su punta hasta el tope respectivo. Las medidas obtenidas con los localizadores electrónicos del foramen se compararon con las conductometrías radiográficas, considerando una tolerancia de 0,5 mm. Para la evaluación estadística, se tomó en cuenta el cálculo de intervalo deconfianza (95 por ciento) realizado a partir de la distribución binomial.Resultados: De los 2053 dientes en los cuales se determinó la longitud de trabajo, 1743 (84,9 por ciento) fueron consideradas medidas correctas, y 310 (15,1 por ciento), incorrectas...

Aim: To assess the training process and results of the useof electronic apex locators in an Aim: To assess the training process and results of the useof electronic apex locators in an undergraduate preclinicalcourse for students from the University del Salvador / AsociaciónOdontológica Argentina between 2005 and 2016.Materials and methods: Two thousand fifty threeextracted human incisors, canines, maxillary and mandibularbicuspid teeth were used. The teeth were mounted withthe roots submerged in saline solution using two methods: a) plastic tubes, b) models simulating the dental arch. Conventionalcoronal access to the root canal was performedand the cervical and middle portions of the root canal wereflared. To determine the working length a K-file with a caliberaccording to the root canal was selected for each tooth andintroduced in the root canal with the clip adjusted in the file.The labial clip was immersed in the model saline solution. Inthe majority of the teeth the advanced and withdrawal techniquewas employed. The level of penetration was establishedusing the light and/or the acoustic signal at 0.5. Then, the rubberstop was adjusted to the reference line and a radiographwas obtained. The instrument was removed and measuredfrom its tip to the rubber stop. The measurements obtainedwith the electronic apex locators were compared with thoseobtained from the X rays considering a tolerance of 0.5 mm.For the statistical evaluation, 95% confidence intervals werecalculated using the binomial distribution.Results: Out of 2053 teeth in which the working lengthwas determined, 1743 (84.9%) were considered correct measurementsand 310 (15.1%) incorrects...

Comparison of two different methods of average working length determination in second molars and premolars / Comparación de dos métodos para determinar la longitud de trabajo promedio en segundos molares y premolares

Within the procedures involved in a successful endodontic treatment is the working length (WL) determination. The root canal end must be detected accurately, and a precise control of the WL must be maintained. There are several methods to determine WL. Researchers have published the average teeth length (ATL) to the human permanent dentition. These measurements are used as an anatomical reference. If the WL is evaluated using a radiographic image, it is accepted as clinical success if the limit of the canal sealing is 1 mm coronal to the root apex. One method to determine WL is based in substract 1 mm to ATL. Another method widely used, assert to achieve a more precise WL determination, through the use of an electronic apex locator (AL). Nevertheless, published measures of ATL are still used as anatomical reference, and are used to determine WL in the absence of an AL. The aim of this study was to determine the average WL of second molars and premolars with endodontic treatment indication using a PropexII® AL, and compare these measurements to WL determination using ATL method. A descriptive cross-sectional study with a non-random sample of consecutive cases was executed. Results showed that there were no statistically significant differences between the WL obtained with AL and ATL method in studied teeth, except mesio-buccal canal of second maxillary molars (19.94 mm average using AL, 1.54 mm greater than ATL method 18.40 mm; p= 0.002). The ATL method to determine WL could be used to determine the WL of second molars and premolars in studied population. Further research should be performed to determine if ATL method is safe and reliable to be used in absence of an AL or in patients where this instrument cannot be used.

Entre los procedimientos involucrados en un tratamiento endodóntico exitoso está la determinación de longitud de trabajo (LT). Esta debe mantenerse durante todo el tratamiento, y el extremo del canal radicular (CR) debe detectarse con precisión. Existen varios métodos para determinar LT; los investigadores han publicado la longitud total promedio (LTP) de la dentición permanente humana. Estas mediciones se utilizan como referencia anatómica. Si LT se evalúa usando una imagen radiográfica, se acepta como éxito clínico cuando el límite de la obturación radicular queda 1 mm coronal al ápice radicular. Un método para determinar LT se basa en restar 1 mm a la LTP. Otro método, que permite una determinación de LT más precisa, se realiza utilizando un localizador apical electrónico (LA). Pese a esto último, las medidas publicadas de LTP todavía se utilizan como referencia anatómica, para determinar LT en ausencia de un LA. El objetivo fue determinar LT promedio de los CR de segundos molares y premolares con indicación de endodoncia utilizando LA PropexII®, y comparar estas mediciones con la LT determinada utilizando el método de LTP. Se realizó un estudio descriptivo de corte transversal con una muestra no probabilística de casos consecutivos. No hubo diferencias estadísticamente significativas entre la LT obtenida con LA y el método LTP en los dientes estudiados, salvo en los canales mesio-bucales de segundos molares superiores (19,94mm promedio usando LA, 1,54 mm mayor que el método LTP: 18,40 mm; p= 0,002). El método para definir LT a través de LTP podría utilizarse para determinar LT de segundos molares y premolares en la población estudiada. Se requieren investigaciones posteriores para determinar si el método que utiliza LTP es confiable para ser utilizado en ausencia de un LA o en pacientes en los que este instrumento no pueda ocuparse.

Effectiveness of three electronic apex locators to determine root canal working length / Efectividad de tres localizadores apicales electrónicos para determinar la longitud radicular de trabajo

This study was to evaluate in vivo the accuracy of three electronic apex locators (EALs) in determining working length (WL) using hand files and a wear technique. Thirty two premolars that were completely formed apically and that were scheduled for extraction for orthodontic reasons from patients between ages of 15 and 20 years old were included. Electronic measurement of WL was performed using the EAL according to the manufacturer’s instructions. The following three EAL were used: A. Root ZX II; B. Raypex 5, and C. Propex II. There were significant difference (p=0.0002) when comparing median differences among the three EAL. Statistical analysis revealed significant differences between Root ZX II vs. Raypex 5 and Root ZX II vs. Propex II (p=0.0044; p=0.0002), while between aypex 5 and Propex II, there were no statistically significant differences with respect to the accuracy of the EAL in determining WL (p=0.1087). The present findings suggest that Root ZX II presented the highest agreement rate for determining the final WL...

Estudio fue evaluar in vivo la exactitud de tres localizadores apicales electrónicos(LAEs) para determinar la longitud de trabajo (LT) usando instrumentos manuales y una técnica de desgaste. Treinta y dos premolares con formación apical completa e indicados para extracción por razones ortodóncicas de pacientes de edad entre 15 y 20 años fueron incluidos en el estudio. Seusaron tres LAE; A. Root ZX II; B. Raypex 5, y C. Propex II. Se encontraron diferencias significativas (p=0.0002) cuando se compararon las medianas entre los tres LAE. El análisismostró diferencias entre Root ZX II vs. Raypex 5 y Root ZX II vs. Propex II (p=0.0044; p=0,0002), mientras queentre Raypex 5 y Propex II, no se encontraron diferencias estadísticamente significativas en la determinación de la LT (p=0.1087). Los presentes hallazgos sugieren que Root ZX II mostró la mayor exactitud para determinar la LT final...

Effectiveness of electronic apex locator during the root canal length in primary teeth: an in vitro study

To evaluate the use of electronic apex locator to measure the root canal length in primary teeth, comparing this measure with the measurements obtained by conventional radiography and by the direct measurement of the root canal lenght.Material and Methods:The sample consisted of nine multi-rooted primary teeth, totaling 32 root canals. Endodontic access was performed with a spherical diamond tip, then the pulp was extirpated and the canal irrigated with 0.9% saline. An endodontic file was used to measure the root canal length by electronic apex locator, using the Novapex ® according to the manufacturer's instructions, and by direct method. An endodontic ruler was used to determine fileÆs length. Conventional radiographic was also performed. Statistical analysis was performed by analysis of variance (ANOVA). The level of significance was 95%.Results:The average of the root canal length was 9.98 ± 2.16 to the direct method; 11.52 ± 1.87 to conventional radiography; and 10.91 ± 1.92 to the electronic apex locator. The results of this study showed a high correlation between the values given by the different methods, regardless of the presence or absence of physiological root resorption. There were not statistically significant differences amongst the methods studied (p> 0.05).Conclusion:Electronic apex locator was an accurate method measure the root canal length in primary teeth, and its use is indicated in endodontic treatment of these teeth...

In Vivo Accuracy of Two Electronic Foramen Locators Based on Different Operation Systems

The aim of this study was to compare in vivo the accuracy of two electronic foramen locators (EFLs) based on different operation systems - Root ZX and Propex II. Ten healthy adult patients needing premolar extractions due to orthodontic reasons participated in the study, providing a sample of 17 noncarious, non-restored, vital teeth (n= 24 canals). After coronal access preparation and cervical preflaring and prior to tooth extraction, the root canal length was measured alternating the two EFLs. All measurements were performed with K-files well fitted to the canal diameter at the level that each EFL indicated the apical foramen in their display (APEX or 0.0). The last K-file were fixed in place with cyanoacrylate, the tooth was extracted, and the apical 4 mm of each root were resected to measure the distance between the file tip and the apical foramen. The mean errors based on the absolute values of discrepancies were 0.30 ± 0.29 mm (Root ZX) and 0.32 ± 0.27 mm (Propex II). Analysis by the Wilcoxon test for paired samples showed no statistically significant differences between the electronic canal measurements performed with the EFLs (p=0.587). The apical foramen was accurately located in 75% (Root ZX) and 66.7% (Propex II) of the cases, considering a ±0.5 mm error margin, with no statistically significant difference by the chi-square test. Despite having different measurement mechanisms, both EFLs were capable of locating the apical foramen with high accuracy in vivo. Under the tested clinical conditions, Root ZX and Propex II displayed similar results.

O presente estudo teve como objetivo avaliar, in vivo, a precisão de dois localizadores eletrônicos foraminais (LEFs) baseados em diferentes mecanismos de funcionamento, Root ZX e Propex II, na determinação do forame apical, sendo utilizados nos mesmos dentes. Após o acesso coronário e o pré-alargamento, e anteriormente à exodontia, os comprimentos de 24 canais radiculares foram determinados eletronicamente alternando-se os dois LEFs. As odontometrias foram realizadas até que os dispositivos apontassem o FA (APEX), utilizando-se limas tipo-K ajustadas. O último instrumento utilizado foi fixado em posição, o dente extraído e os 4,0 mm apicais de cada canal desgastados de forma a possibilitar a determinação da distância entre a ponta dos instrumentos e o forame apical. Os erros médios em função dos valores absolutos das discrepâncias foram, respectivamente, 0,30 ± 0,29 mm (Root ZX) e 0,32 ± 0,27 mm (Propex II). A análise estatística realizada por meio do teste de Wilcoxon para amostras pareadas demonstrou a semelhança entre as determinações do forame apical realizadas pelos dois LEFs (p=0,587). O comprimento radicular até o forame apical foi corretamente determinado em 75% (Root ZX) e 66,7% (Propex II) dos casos, considerando margem de ± 0,5 mm, sem diferenças estatísticas quando analisados pelo teste qui-quadrado. Os LEFs avaliados e consequentemente seus mecanismos de funcionamento, foram capazes de determinar o comprimento dos canais radiculares com precisão em condições in vivo. Nas condições do presente estudo, Root ZX e Propex II apresentaram resultados semelhantes.

Not all electronic foramen locators are accurate in teeth with enlarged apical foramina: an in vitro comparison of 5 brands.

INTRODUCTION: Electronic working length measurement during root canal treatment in teeth with enlarged apical foramina is a challenge. The aims of this in vitro study were (1) to assess the influence of foramen widening on the accuracy of 5 different electronic foramen locators (EFLs) and (2) to compare the accuracy of EFLs in different foramen sizes. METHODS: The following EFLs were used: MiniApex, Root ZXII, iPex, Propex II, and Elements Apex Locator. Each EFL was used in 3 groups (n = 20) of extracted teeth, with foramen diameters of 0.27 mm (G27), 0.47 mm (G47), and 0.72 mm (G72). Working length was measured according to manufacturer's instructions and compared with visual measurements (control method). Results were classified as accurate (equal or differences ≤ 0.05 mm) or inaccurate (differences > 0.5 mm). RESULTS: In G27, all EFLs yielded accurate findings (intragroup reliability; Fisher exact test, P < .05), compared with only MiniApex, Root ZXII, and Elements Apex Locator in G47 and G72. MiniApex, Root ZXII, and Elements Apex Locator were similarly accurate regardless of foramen size. iPex and Propex II were the least accurate among the devices tested, and foramen diameter influenced their accuracy, with greater diameters yielding poorer EFL performance. CONCLUSIONS: Foramen diameter did not influence the accuracy of MiniApex, Root ZXII, and Elements Apex Locator EFLs. iPex and Propex II showed decreased accuracy as foramen size increased.

An in vivo radiographic evaluation of the accuracy of Apex and iPex electronic Apex locators

The aim of this study was to evaluate in vivo the clinical applicability of two electronic apex locators (EALs) - Apex (Septodont) and iPex (NSK) - in different groups of human teeth by using radiography. The working lengths (WLs) of 100 root canals were determined electronically. The EAL to be used first was chosen randomly and a K-file was inserted into the root canal until the EAL display indicated the location of the apical constriction (0 mm). The K-file was fixed to the tooth and a periapical radiograph was taken using a radiographic film holder. The K-file was removed and the WL was measured. The same procedure was repeated using the other EAL. Radiographs were examined with the aid of a light-box with lens of ×4 magnification by two blinded experienced endodontists. The distance between the file tip and the root apex was recorded as follows: (A) +1 to 0 mm, (B) -0.1 to 0.5 mm, (C) -0.6 to 1 mm, (D) -1.1 to 1.5 mm, and (E) -1.6 mm or greater. For statistical purposes, these scores were divided into 2 subgroups according to the radiographic apex: acceptable (B, C, and D) and non-acceptable (A and E). Statistically significant differences were not found between the results of Apex and iPex in terms of acceptable and non-acceptable measurements (p>0.05) or in terms of the distance recorded from file tip and the radiographic apex (p>0.05). Apex and iPex EALs provided reliable measurements for WL determination for endodontic therapy.

O objetivo deste estudo foi avaliar, in vivo, a aplicabilidade clínica de dois localizadores apicais eletrônicos (LAEs) - Apex (Septodont) e iPex (NSK) - em diferentes grupos de dentes humanos usando análise radiográfica. Os comprimentos de trabalho de 100 canais radiculares foram determinados eletronicamente. O LAE a ser usado primeiro foi escolhido randomicamente e uma lima tipo K foi inserida no canal radicular até que o visor do aparelho indicasse a localização da constrição apical (0 mm). A lima foi fixada na coroa do dente e uma radiografia periapical foi realizada utilizando posicionador radiográfico. Em seguida, a lima foi removida e o comprimento de trabalho foi mensurado. O mesmo procedimento foi realizado para o segundo LAE. As radiografias foram analizadas em negatoscópio com lupa de ×4 por dois endodontistas experientes, cegos em relação aos grupos. A distância entre a ponta da lima e o ápice radiográfico foi classificada como: (A) + 1 a 0 mm; (B) - 0,1 a 0,5 mm; (C) - 0,6 a 1 mm; (D) - 1,1 a 1,5 mm; e (E) - 1,6 mm ou mais. Para fins estatísticos, esta classificação foi dividida em dois sub-grupos: aceitável (B, C, D) e não aceitável (A e E). Não foi observada diferença estatisticamente significante entre Apex e iPex em relação às medições consideradas aceitáveis e não aceitáveis (p>0,05) e nem à distância da ponta da lima e o ápice radiográfico (p>0,05). Os localizadores apicais Apex e iPex apresentaram medidas odontométricas confiáveis para o tratamento endodôntico.