The purpose of this in-vitro study is to compare the accuracy and reliability of a 3rd and 4th generation electronic apex locator (EAL) in locating the apical foramen when using insulated and non-insulated K files. Forty extracted human adult single-rooted teeth were coronally sectioned and placed in agar. EAL determined tooth length measurements were compared to actual tooth measurements. Comparisons to the standard measures used correlation and paired t-test. Preliminary comparisons of the groups used ANOVA to compare the means and the Brown-Forsythe test to compare variance. In the final analyses, the measurements were compared using a repeated-measures mixed-model multiway ANOVA that allowed for heterogeneous variance in the subgroups. Findings were that accuracy is not different due to insulation in the Root ZX group (p-value=0.50) but is improved in the Elements Diagnostic Unit group (p-value<.001). Reliability is nominally improved with insulation in both the Root ZX and Elements Diagnostic Unit.

The aim of this study was to determine the change in working length (∆WL) before and after coronal flaring and after complete rotary instrumentation as a function of canal curvature. One mesiobuccal or mesiolingual canal from each of 43 extracted molars had coronal standardization and access performed. Once the access was completed, canal preparation was accomplished using Gates Glidden drills for coronal flaring and EndoSequence files for rotary instrumentation. WLs were obtained at 3 time points: pre-instrumentation (unflared), mid-instrumentation (flared) and post-instrumentation (concluded). Measurements were made via direct visualization (DV) and the CanalPro apex locator (EM) in triplicate by a single operator with blinding across the time points. Root curvature was measured using Schneider’s technique. The change in working length was assessed using repeated-measures ANCOVA. The direct visualization measurements were statistically larger than the electronic measurements (paired t-test difference = 0.20 mm, SE = 0.037, P < .0001), although a difference this large may not be clinically important. Overall, a greater change in working length was observed in straight canals than in curved canals. This unexpected finding was attributed to the limitations of the study, specifically the confounding factor of root length. This trend was more pronounced when measured electronically than via direct visualization, especially after complete instrumentation than after coronal flaring. The overall change in working length after complete instrumentation was found to be clinically insignificant in this study. A limited amount of change in working length may be expected prior to obturation.

Aim: The aim of this study was to evaluate the accuracy of the Wirele-X (Forum Tec, Ashkelon, Israel), a new Bluetooth-enabled electronic apex locator (EAL). The accuracy of the Wirele-X and the Root ZX II (J. Morita, Tokyo, Japan) was compared in vitro using an alginate model. Materials/Methods: Thirty-one extracted single-rooted human teeth with mature apices were decoronated at the CEJ. Under 10X magnification, actual canal lengths (ACL) were determined. The teeth were embedded in alginate and electronic canal length measurements were obtained using the Root ZX II and Wirele-X EALs. Each tooth was measured three times with both EALs. A blinded examiner measured each file with a digital micrometer to the nearest 0.01 mm. Differences between ACLs and the average measurements from the EALs were compared with Student's t test for related samples. Results: The average distance from the file tip to the apical foramen (AF) was -0.11 mm (±0.16) and -0.07 mm (±0.21) for the Root ZX II and Wirele-X systems, respectively. There were no statistically significant differences between the two apex locators in their ability to locate the AF (p > 0.05). Conclusions: Both the Wirele-X and the Root ZX II provided a high level of accuracy and reliability in locating the AF.

The aims of this study were to determine the efficacy of the KontrolFlexTM AccufileTM compared to the READY•STEEL™ Flexofile® using an electronic apex locator and to evaluate the instrument’s design via scanning electron microscopy. Actual canal lengths of thirty extracted teeth were determined under magnification. An alginate model was used to determine experimental canal lengths with the Root ZX II apex locator and size #10 Accufiles and Flexofiles. Differences between actual lengths and experimental lengths were compared with Student’s t test. The average experimental lengths were short of the actual length by -0.10 mm (±0.34) and -0.12 mm (±0.16) for the Accufile and Flexofile, respectively with no statistical difference (p > 0.05). SEM images revealed similar non-cutting “batt” tips and a square cross-section for the Accufile and triangular for the Flexofile. Both files provided similarly high levels of reliability when used with the Root ZX II electronic apex locator.

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 a seqüência de instrumentação e medida até a lima tipo K no 130; a lima tipo K no 10 foi utilizada em todos os diâmetros. Terminada essa fase, os dentes tiveram os canais sobreinstrumentados, isto é, a ponta da lima ultrapassou o forame apical em 1,0mm, a partir da lima tipo K no 25 e seguindo até a lima tipo K no 130; novas medidas foram obtidas com cada lima que sobreinstrumentou o forame e a lima no 10 foi utilizada em todos os diâmetros. Em todos os casos o canal radicular estava preenchido com hipoclorito de sódio a 1%. Para a análise estatística foram empregados os testes de Análise de Variância a dois critérios e de Tukey. Os resultados indicaram que as variáveis capazes de influenciar a recisão das leituras com os localizadores foraminais eletrônicos foram a eliminação da constrição apical com o consequente aumento do diâmetro do forame apical, ao contrário da espessura da parede dentinária do canal radicular, que não interferiu significativamente na precisão das leituras. / 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 beyond the apical foramen, beginning with 25 K file up to 130 K file; new measurements were obtained with each file overinstrumenting the apical foramen, and the 10 K file was used in all diameters. In all cases, the root canal was irrigated with 1% sodium hypochlorite. Statistical analysis was performed by two-way analysis of variance and the Tukey test. The results indicated that the variables that may influence the accuracy of readings with the electronic apex locators were the elimination of apical constriction with consequent increase in the diameter of the apical foramen, different from the thickness of the root canal dentinal wall, which did not significantly influence the accuracy of readings.

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 a seqüência de instrumentação e medida até a lima tipo K no 130; a lima tipo K no 10 foi utilizada em todos os diâmetros. Terminada essa fase, os dentes tiveram os canais sobreinstrumentados, isto é, a ponta da lima ultrapassou o forame apical em 1,0mm, a partir da lima tipo K no 25 e seguindo até a lima tipo K no 130; novas medidas foram obtidas com cada lima que sobreinstrumentou o forame e a lima no 10 foi utilizada em todos os diâmetros. Em todos os casos o canal radicular estava preenchido com hipoclorito de sódio a 1%. Para a análise estatística foram empregados os testes de Análise de Variância a dois critérios e de Tukey. Os resultados indicaram que as variáveis capazes de influenciar a recisão das leituras com os localizadores foraminais eletrônicos foram a eliminação da constrição apical com o consequente aumento do diâmetro do forame apical, ao contrário da espessura da parede dentinária do canal radicular, que não interferiu significativamente na precisão das leituras. / 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 beyond the apical foramen, beginning with 25 K file up to 130 K file; new measurements were obtained with each file overinstrumenting the apical foramen, and the 10 K file was used in all diameters. In all cases, the root canal was irrigated with 1% sodium hypochlorite. Statistical analysis was performed by two-way analysis of variance and the Tukey test. The results indicated that the variables that may influence the accuracy of readings with the electronic apex locators were the elimination of apical constriction with consequent increase in the diameter of the apical foramen, different from the thickness of the root canal dentinal wall, which did not significantly influence the accuracy of readings.

Made available in DSpace on 2014-07-29T15:21:58Z (GMT). No. of bitstreams: 1 Dissertacao Andre Luiz Gomide de Morais.pdf: 1627953 bytes, checksum: 05ab427707618c3afdeb890e320268e6 (MD5) Previous issue date: 2012-02-13 / Introduction Strategies to obtain the working length to prepare and fill the root canals has been relevant theme of discussion in endodontics. The purpose of this study was to compare in vivo the canal root working length measures determined by cone beam computed tomography (CBCT) images with the ones obtained by using periapical radiograph and electronic apex locator. Methods The root canal working lengths of 30 single-rooted teeth from 19 patients whose diagnosis was apical periodontitis were evaluated. Initial periapical radiographs for diagnosis and treatment planning, employing the parallelism technique, were taken. CBCT images were acquired with i-CAT system (aiming of diagnosing the cases of apical periodontitis that showed to be complex and doubtful) and measured with specific function of i-CAT software. The coronal opening was made, the root canals were irrigated with sodium hypochlorite solution 2.5%, being performed the exploration and initial emptying of root canal. After, the preparation of the inlet orifice and of the cervical root third was carried out . The minor foramen was located using Root ZX® locator by advancing a stainless steel K-file that best suited the root canal, according to the manufacturer´s instructions. The radiographic measurement was made by advancing a stainless steel K-file in the root canal, until its tip was 1.0 mm from the root apex (determined from the measures obtained by the electronic ape locator). These 3 working length were tabulated and compared. Kruskal-Wallis test was used to analyze the differences between working lengths methods. The significance was set at &#945;=5%. Results The mean values and standard deviations for working length determination by electronic apex locator, periapical radiograph and CBCT images were 21.5 ± 3.1, 21.32 ± 3, 21.4 ± 2.7, respectively. Significant differences were not verified statistically (P>0.05). Conclusions CBCT images working length determination showed to be as similar as the determinations obtained by using periapical radiograph and electronic apex locator. / Introdução: Estratégias para obtenção do comprimento de trabalho para preparar e obturar canais radiculares têm sido tema relevante de discussão em Endodontia. O objetivo deste estudo foi comparar in vivo as medidas de comprimento de trabalho do canal radicular determinadas por meio da tomografia computadorizada de feixe cônico (TCFC) com as obtidas por meio de radiografia periapical e localizador apical eletrônico. Metodologia: Foram avaliados os comprimentos de trabalho dos canais radiculares em 30 dentes de 19 pacientes com diagnóstico de periodontite apical. Radiografias periapicais iniciais de diagnóstico e plano de tratamento, empregando a técnica do paralelismo, foram realizadas. As imagens de TCFC foram obtidas usando o sistema i-CAT (com o intuito de diagnosticar os casos de periodontite apical que se mostraram complexos ou duvidosos) e foram medidas a partir de função específica do programa desse sistema. Foi realizada a abertura coronária, os canais radiculares foram irrigados solução de hipoclorito de sódio a 2,5%, sendo realizada a exploração e o esvaziamento inicial do canal radicular. Depois foi realizado o preparo do orifício de entrada e do terço cervical da raiz. O forame apical foi localizado usando o localizador Root ZX® por meio do avanço de uma lima tipo K-file que melhor se adaptasse ao canal radicular de aço inoxidável no canal radicular, de acordo com instruções do fabricante. A medida radiográfica foi feita por meio da colocação de uma lima tipo K-file de aço inoxidável no canal radicular, até que sua ponta estivesse a 1,0mm do ápice radicular (determinado pelas medidas obtidas com o localizador apical eletrônico). Essas três medidas de comprimento de trabalho foram tabuladas e comparadas. O teste de Kruskal-Wallis foi empregado para analisar as diferenças entre os métodos de obtenção dos comprimentos de trabalho. O nível de significância foi estabelecido em &#945;=5%. Resultados: O valor médio e os desvios-padrões para a determinação do comprimento de trabalho por meio de imagens de TCFC, localizador apical eletrônico e radiografia periapical foram de e 21,4 ± 2,7, 21,5 ± 3,1, 21,32 ± 3, respectivamente. Diferenças significantes entre as medidas obtidas pelos três métodos não foram verificadas (p>0.05). Conclusões: A determinação do comprimento de trabalho em imagens de TCFC mostrou ser tão similar quanto às determinações obtidas por meio do método radiográfico e do localizador apical eletrônico.