In Vitro Comparative Study Of Four Electronic Apex Locators In Detecting Apical Constriction

Objective: Minor constriction which is the narrowest diameter is considered to be the appropriate apical limit of endodontic treatment. Apex locators provide greater precision, fewer procedural errors, less discomfort to the patient during measurement of working length. The aim of this article is to compare the accuracy of four electronic apex locators in detecting the apical constriction using histological sections as the gold standard. 80Materials and Methods: extracted single-rooted permanent teeth were selected and coronally flattened for stable reference point. Access cavity was prepared and canal patency was checked. Samples were embedded in alginate upto cemento-enamel junction. Working length was determined with the apex locators. A 15 K file adjusted to that reading was placed in the root canal and stabilized with flowable composite. Apical 4 mm of root was longitudinally sectioned and the position of the file in relation to the minor constriction was recorded for each tooth under stereomicroscope at 40X magnification. Chi-square test was carried out to test the difference in accuracy at various levels from the minor foramen. Kruskal Wallis Test was carried out to compare the differences between the study groups for the distance from the tip of the file relative to the minor foramen (P<0.05). Measurements of mean working lengths within ±0.5 mm of minor diameter were 85%Results: acceptable for CanalPro followed by Root ZX Mini (80%) and Propex Pixi (80%) and the least by DPEX V (65%). Conclusion: Accuracy of these instruments for detecting the minor diameter is acceptable for clinical practice

Effect of Materials For Interim Restoration on Estimation of Working Length Using Electronic Apex Locator: in vitro Study

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.

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)

Comparison between Conventional Radiography, Radiovisiography and Raypex 5 Electronic Apexlocator in Determining the Root Canal Length in Posterior Teeth- An Invitro Study

The determination of working length and its maintenance during cleaning and shaping procedures is a key factor for successful endodontic treatment. The aim of this in- vitro study was to evaluate the utility and accuracy of Raypex5 electronic apex locator in determining the working length in comparison to conventional radiography and radiovisiography in posterior teeth. Methods: In this study sixty extracted mandibular first and second molars were used. Diagnostic images were obtained both by conventional radiography and radiovisiography (RVG) and tentative working length was obtained and recorded. After access opening actual root canal length was determined by both conventional radiography and RVG and recorded. Four blinded observers determined the working length in all samples with Raypex5 electronic apex locator. Then at that length file position was checked using RVG. Results: All the data collected was statistically analyzed using one way analysis of variance (ANOVA), Cronbach’s alpha reability analysis and student paired t-test. Conclusion: In this study it was found that Electronic apexlocator Raypex 92 %, RVG 74% and conventional radiograph was 70% accurate in measuring root canal length in posterior teeth.

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.

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...

An in vitro evaluation of the accuracy of four electronic apex locators using stainless-steel and nickel-titanium hand files

OBJECTIVES: The purpose of this in vitro study was to evaluate the accuracy of working length (WL) determination of four electronic apex locators (EALs), namely, Root ZX (RZX), Elements diagnostic unit and apex locator (ELE), SybronEndo Mini Apex locator (MINI) and Propex pixi (PIXI) using Stainless steel (SS) and nickel-titanium (NiTi) hand files. The null hypothesis was that there was no difference between canal length determination by SS and NiTi files of 4 EALs. MATERIALS AND METHODS: Sixty extracted, single rooted human teeth were decoronated and the canal orifice flared. The actual length (AL) was assessed visually, and the teeth were embedded in an alginate model. The electronic length (EL) measurements were recorded with all four EALs using SS and NiTi files at '0.5' reading on display. The differences between the AL and EL were compared. RESULTS: The results obtained with each EAL with SS and NiTi files were compared with AL. A paired sample t test showed that there was a statistical significant difference between EAL readings with SS and NiTi files for RZX and MINI (p < 0.05). The accuracy of RZX, ELE, MINI and PIXI within +/- 0.5 mm of AL with SS/NiTi files were 93.3%/70%, 90%/91.7%, 95%/68.3%, and 83.3%/83.3%, respectively. CONCLUSIONS: The results of this study indicate that Root ZX was statistically more accurate with NiTi files compared to SS files, while MINI was statistically more accurate with SS files compared to NiTi files. ELE and PIXI were not affected by the alloy type of the file used to determine WL.

An in vitro evaluation of the accuracy of four electronic apex locators using stainless-steel and nickel-titanium hand files

OBJECTIVES: The purpose of this in vitro study was to evaluate the accuracy of working length (WL) determination of four electronic apex locators (EALs), namely, Root ZX (RZX), Elements diagnostic unit and apex locator (ELE), SybronEndo Mini Apex locator (MINI) and Propex pixi (PIXI) using Stainless steel (SS) and nickel-titanium (NiTi) hand files. The null hypothesis was that there was no difference between canal length determination by SS and NiTi files of 4 EALs. MATERIALS AND METHODS: Sixty extracted, single rooted human teeth were decoronated and the canal orifice flared. The actual length (AL) was assessed visually, and the teeth were embedded in an alginate model. The electronic length (EL) measurements were recorded with all four EALs using SS and NiTi files at '0.5' reading on display. The differences between the AL and EL were compared. RESULTS: The results obtained with each EAL with SS and NiTi files were compared with AL. A paired sample t test showed that there was a statistical significant difference between EAL readings with SS and NiTi files for RZX and MINI (p < 0.05). The accuracy of RZX, ELE, MINI and PIXI within +/- 0.5 mm of AL with SS/NiTi files were 93.3%/70%, 90%/91.7%, 95%/68.3%, and 83.3%/83.3%, respectively. CONCLUSIONS: The results of this study indicate that Root ZX was statistically more accurate with NiTi files compared to SS files, while MINI was statistically more accurate with SS files compared to NiTi files. ELE and PIXI were not affected by the alloy type of the file used to determine WL.

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...

Evaluation of electrical impedance ratio measurements in accuracy of electronic apex locators

OBJECTIVES: The aim of this paper was evaluating the ratios of electrical impedance measurements reported in previous studies through a correlation analysis in order to explicit it as the contributing factor to the accuracy of electronic apex locator (EAL). MATERIALS AND METHODS: The literature regarding electrical property measurements of EALs was screened using Medline and Embase. All data acquired were plotted to identify correlations between impedance and log-scaled frequency. The accuracy of the impedance ratio method used to detect the apical constriction (APC) in most EALs was evaluated using linear ramp function fitting. Changes of impedance ratios for various frequencies were evaluated for a variety of file positions. RESULTS: Among the ten papers selected in the search process, the first-order equations between log-scaled frequency and impedance were in the negative direction. When the model for the ratios was assumed to be a linear ramp function, the ratio values decreased if the file went deeper and the average ratio values of the left and right horizontal zones were significantly different in 8 out of 9 studies. The APC was located within the interval of linear relation between the left and right horizontal zones of the linear ramp model. CONCLUSIONS: Using the ratio method, the APC was located within a linear interval. Therefore, using the impedance ratio between electrical impedance measurements at different frequencies was a robust method for detection of the APC.

Evaluation of electrical impedance ratio measurements in accuracy of electronic apex locators

OBJECTIVES: The aim of this paper was evaluating the ratios of electrical impedance measurements reported in previous studies through a correlation analysis in order to explicit it as the contributing factor to the accuracy of electronic apex locator (EAL). MATERIALS AND METHODS: The literature regarding electrical property measurements of EALs was screened using Medline and Embase. All data acquired were plotted to identify correlations between impedance and log-scaled frequency. The accuracy of the impedance ratio method used to detect the apical constriction (APC) in most EALs was evaluated using linear ramp function fitting. Changes of impedance ratios for various frequencies were evaluated for a variety of file positions. RESULTS: Among the ten papers selected in the search process, the first-order equations between log-scaled frequency and impedance were in the negative direction. When the model for the ratios was assumed to be a linear ramp function, the ratio values decreased if the file went deeper and the average ratio values of the left and right horizontal zones were significantly different in 8 out of 9 studies. The APC was located within the interval of linear relation between the left and right horizontal zones of the linear ramp model. CONCLUSIONS: Using the ratio method, the APC was located within a linear interval. Therefore, using the impedance ratio between electrical impedance measurements at different frequencies was a robust method for detection of the APC.

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.

An in vivo comparative evaluation to determine the accuracy of working length between radiographic and electronic apex locators.

Background: An in vivo comparative evaluation to determine the accuracy of working length between radiographic and electronic apex locators. Aim: The study was aimed at evaluating the accuracy of electronic apex locator, to determine the working length of root canal, and to compare it with the radiographic method of working length determination. Materials and Methods: A total of 20 teeth selected for the study had to go for extraction because of periodontal or orthodontic reasons. Access cavity was prepared and the clinical estimated working length (CEWL) was determined with 10-25 no. K-file. A radiograph was then taken for determining the radiographic estimated working length (REWL). For electronic measurement of root canal, a 10 no. K-file was advanced toward the apex until it reached a 0.5 mm short of apex as shown by the apex locator. After fixing the file with a light cured composite, the tooth was extracted, the tooth surface was then longitudinally grounded using straight fissure diamond bur until the root canal and the tip of the file were visible. The distance of file from the minor constriction was measured with help of stereomicroscope. Statistical analysis : The chi-square test was used for statistical analysis for this study. Results: The chi-square test where χ2 = 21.034 with P = 0.000 indicated that a significant difference exists among the groups. The electronic method showed highest number of cases with the working length at the minor constrictor. Conclusion: The electronic method for determining the working length of root canal was found to be more accurate than the radiographic method.

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.

An evaluation of the accuracy of Root ZX according to the conditions of major apical foramen

OBJECTIVES: The purpose of this study was to assess the accuracy of Root ZX (J. Morita Corp.) according to the location of major foramen and open apex. MATERIALS AND METHODS: 81 mandibular premolars with mature apices were selected. After access preparation, 27 teeth were instrumented to simulate open apices. 54 teeth were classified according to location of major foramen under surgical microscope (x16). The file was fixed at the location of apical constriction by Root ZX using glass ionomer cement. The apical 4 mm of the apex was exposed and photo was taken and the distance from file tip to the major foramen was measured by calibrating metal ruler on graph paper. The results were statistically analyzed using ANOVA and Scheffe test at p < 0.05 level. RESULTS: Mean distance from file tip to major foramen was 0.308 mm in Tip foramen group (I), 0.519 mm in Lateral foramen group (II) and 0.932 mm in open apex group (III). Root ZX located apical constriction accurately within +/- 0.5 mm in group I of 85.71%, in group II of 59.09%, and in group III of 33.33%. There was a statistically significant difference between group I and III (p < 0.05). CONCLUSION: Root ZX located apical constriction accurately regardless of location of major foramen. However, Root ZX couldn't find it in open apex. Clinicians have to use a combination of methods to determine an appropriate working length at open apex. It may be more successful than relying on just electronic apex locator.

Influência da espessura de dentina, da constrição apical e do diâmetro do forame apical na precisão de leitura com localizadores foraminais eletrônicos / Influence of dentin thickness, apical constriction and diameter of the apical foramen in the accuracy of readings with electronic apex locators

Este trabalho teve como objetivo avaliar a influência da espessura de dentina radicular apical, da constrição apical e do diâmetro do forame apical na precisão de leituras realizadas com os localizadores foraminais eletrônicos Mini Apex Locator e Root ZX II®. Foram utilizados 30 incisivos inferiores permanentes unirradiculados de humanos, extraídos, com raízes íntegras e ápices completamente formados e portadores de um único canal. Por meio de um paquímetro, as espessuras radiculares dos dentes foram medidas, no sentido mésio-distal a 1,0 e a 4,0mm aquém do forame apical. Após a abertura coronária, uma lima tipo K no 10, munida de limitador de penetração, foi introduzida no canal radicular até que sua extremidade pudesse ser visualizada na altura do forame, com o auxílio de um microscópio óptico com aumento de 7,8X. Dessa medida, subtraiu-se 1,0mm, estabelecendo-se o comprimento de trabalho. A dilatação do canal radicular foi feita, inicialmente, com brocas de Gates Glidden, em ordem numérica decrescente, da número 5 até a número1, até 4,0mm aquém do forame apical. Os dentes foram fixados em um modelo experimental especialmente desenvolvido para permitir a medição com os localizadores foraminais eletrônicos. Tal modelo era constituído por dois segmentos de PVC: um de menor calibre, com diâmetro correspondente a meia polegada por 2,0cm de comprimento, com as duas extremidades abertas e outro, de maior calibre, com uma das extremidades fechada e com diâmetro interno equivalente ao diâmetro externo do primeiro segmento (3/4 de polegada). No segmento de maior diâmetro, foi feito um orifício lateral que permitiu o posicionamento do eletrodo labial do localizador foraminal eletrônico e, para a medição, no seu interior, foi colocado alginato e, então, encaixado o componente de menor diâmetro, fazendo com que o ápice radicular ficasse imerso no alginato. Foram realizadas as leituras com os localizadores, iniciando-se com a lima tipo K no 10 e seguindo-se...

This study evaluated the influence of the apical root dentin thickness, apical constriction and diameter of the apical foramen in the accuracy of readings obtained using the electronic apex locators Mini Apex Locator and Root ZX II ®. The study was conducted on 30 extracted human single-rooted permanent mandibular incisors, with intact and completely formed roots and presenting a single canal. The root thickness of the teeth was measured with a pachymeter in mesiodistal direction, at 1.0 and 4.0mm from the apical foramen. After coronal opening, a 10 K file with a stop was introduced in the root canal until its end could be observed at the level of the apical foramen, with aid of a light microscope with 7.8X magnification. One millimeter was subtracted from this measurement for establishment of the working length. Enlargement of the root canal was initially performed using Gates Glidden burs, in decreasing order, from number 5 to number 1, up to 4.0mm beyond the apical foramen. The teeth were fixated in an experimental model especially designed to allow the measurement with the electronic apex locators. This model was composed of two PVC segments: one smaller, with diameter corresponding to half inch with 2.0cm length, with both ends open; and the other, with larger diameter, with one end closed and internal diameter similar to the external diameter of the first segment (3/4 inch). In the segment with greater diameter, a lateral orifice was made to allow positioning of the lip electrode of the electronic apex locator. For the measurement, alginate was poured and the component with smaller diameter was fitted, so as the root apex was immersed in alginate. Readings were performed using the electronic apex locators, initiating with a 10 K file and following the sequence of instrumentation and measurement up to 130 K file. The 10 K file was used in all diameters. After this stage, the root canals were overinstrumented, i.e. the file tip was introduced until 1.0mm...

Influência da espessura de dentina, da constrição apical e do diâmetro do forame apical na precisão de leitura com localizadores foraminais eletrônicos / Influence of dentin thickness, apical constriction and diameter of the apical foramen in the accuracy of readings with electronic apex locators

Este trabalho teve como objetivo avaliar a influência da espessura de dentina radicular apical, da constrição apical e do diâmetro do forame apical na precisão de leituras realizadas com os localizadores foraminais eletrônicos Mini Apex Locator e Root ZX II®. Foram utilizados 30 incisivos inferiores permanentes unirradiculados de humanos, extraídos, com raízes íntegras e ápices completamente formados e portadores de um único canal. Por meio de um paquímetro, as espessuras radiculares dos dentes foram medidas, no sentido mésio-distal a 1,0 e a 4,0mm aquém do forame apical. Após a abertura coronária, uma lima tipo K no 10, munida de limitador de penetração, foi introduzida no canal radicular até que sua extremidade pudesse ser visualizada na altura do forame, com o auxílio de um microscópio óptico com aumento de 7,8X. Dessa medida, subtraiu-se 1,0mm, estabelecendo-se o comprimento de trabalho. A dilatação do canal radicular foi feita, inicialmente, com brocas de Gates Glidden, em ordem numérica decrescente, da número 5 até a número1, até 4,0mm aquém do forame apical. Os dentes foram fixados em um modelo experimental especialmente desenvolvido para permitir a medição com os localizadores foraminais eletrônicos. Tal modelo era constituído por dois segmentos de PVC: um de menor calibre, com diâmetro correspondente a meia polegada por 2,0cm de comprimento, com as duas extremidades abertas e outro, de maior calibre, com uma das extremidades fechada e com diâmetro interno equivalente ao diâmetro externo do primeiro segmento (3/4 de polegada). No segmento de maior diâmetro, foi feito um orifício lateral que permitiu o posicionamento do eletrodo labial do localizador foraminal eletrônico e, para a medição, no seu interior, foi colocado alginato e, então, encaixado o componente de menor diâmetro, fazendo com que o ápice radicular ficasse imerso no alginato. Foram realizadas as leituras com os localizadores, iniciando-se com a lima tipo K no 10 e seguindo-se...

This study evaluated the influence of the apical root dentin thickness, apical constriction and diameter of the apical foramen in the accuracy of readings obtained using the electronic apex locators Mini Apex Locator and Root ZX II ®. The study was conducted on 30 extracted human single-rooted permanent mandibular incisors, with intact and completely formed roots and presenting a single canal. The root thickness of the teeth was measured with a pachymeter in mesiodistal direction, at 1.0 and 4.0mm from the apical foramen. After coronal opening, a 10 K file with a stop was introduced in the root canal until its end could be observed at the level of the apical foramen, with aid of a light microscope with 7.8X magnification. One millimeter was subtracted from this measurement for establishment of the working length. Enlargement of the root canal was initially performed using Gates Glidden burs, in decreasing order, from number 5 to number 1, up to 4.0mm beyond the apical foramen. The teeth were fixated in an experimental model especially designed to allow the measurement with the electronic apex locators. This model was composed of two PVC segments: one smaller, with diameter corresponding to half inch with 2.0cm length, with both ends open; and the other, with larger diameter, with one end closed and internal diameter similar to the external diameter of the first segment (3/4 inch). In the segment with greater diameter, a lateral orifice was made to allow positioning of the lip electrode of the electronic apex locator. For the measurement, alginate was poured and the component with smaller diameter was fitted, so as the root apex was immersed in alginate. Readings were performed using the electronic apex locators, initiating with a 10 K file and following the sequence of instrumentation and measurement up to 130 K file. The 10 K file was used in all diameters. After this stage, the root canals were overinstrumented, i.e. the file tip was introduced until 1.0mm...

In vivo evaluation of accuracy and consistency of two electronic apex locators / 대한치과보존학회지

OBJECTIVES: To evaluate the accuracy and consistency of two different apex locators at both the Apex and 0.5 marks. MATERIALS AND METHODS: Twenty-six root canals was scheduled for extraction for periodontal or prosthodontic reasons. Thirteen canals were measured using Root ZX and the rest by i-ROOT. The root canal length was measured both the at 0.5 mark and the Apex mark. The file was then fixed to the tooth, and the distance from the file tip to the major foramen of each canal was measured after removing the root dentin under the microscope so that the major foramen and the file tip were seen. RESULTS: 1. When the Apex mark was used, 100% of both the Root ZX and i-ROOT groups were within 0.5 mm of the major foramen. 2. When 0.5 mark was used, 100% of the Root ZX group and 77% of the i-ROOT group were within 0.5 mm of the major foramen. 3. In terms of standard deviation and quartile value, the Apex mark was more consistent than 0.5 mark in the Root ZX group, and 0.5 mark was more consistent in the i-ROOT group, but there was no statistically significant difference when compared with t-test. 4. The root canal length difference between the Apex mark and 0.5 mark was 0.22 mm and 0.46 mm in the Root ZX and i-ROOT groups, respectively. CONCLUSIONS: In this study, the Apex mark was the more consistent mark. Therefore, it is recommended to subtract 0.5 mm, which is the average length between the apex and apical constriction, from the root canal length at the Apex mark to obtain the working length clinically.