Accuracy of Root ZX mini and Raypex 6 in locating the apical foramen of molars: radiographic and microscopic evaluation

Introduction: The precise localization of the apical foramen and the odontometry determination is an important stage since it locates the apical limit for instrumentation and filling. Objective: To compare the accuracy of Root-ZX Mini and Raypex 6 in locating apical foramen in extracted molars. Material and methods: 80 mesial and buccal canals from 40 mandibular and maxillary human molars were used. A size #15 K-file was introduced to canal, until the locator indicated the apical foramen (red bar/line in both devices). With the file in position, it was re-adjusted for Root-ZX II Mini on the green bar and on the two yellow bars for Raypex 6. All the samples were measured from the tip of the file to the apical foramen with radiovisiograph and the Sidexis software. The apical third of the root was shaved until exposure of the file. The distance from the file tip to the most coronal border of the apical foramen was obtained and it was measured with a clinical microscope at 16-fold magnification. The measured lengths with the radiovisiograph and the clinical microscope were analyzed with the statistical Student's T-test. Results: The average length from the tip of the file to the apical foramen using Root-ZX Mini was 0.695 mm and 0.543 mm with Raypex 6. There was no significant difference. Conclusion: Two devices were accurate in locating apical foramen with an adequate level of reliability.

Effectiveness of an electronic apex locator used after preflaring of cervical and middle third

Introduction: The electronic method has been studied and improved aiming to add precision, speed and reliability of the measurement technique to determine the exact location of the working length. Currently, the root canal preparation recommends prior to determine the tooth length and consequent perform instrumentation of the apical portion, a previous preflaring of the cervical and middle thirds in various techniques. This procedure may provide a reduction in system impedance, leading to read errors by the apex locators. Objective: Investigate the influence of preflaring of the cervical and middle thirds on the accuracy of measuring the working length by apex locators. Material and methods: Twenty-five mesial roots of molars were used and had their crowns cut at the cemento-enamel junction. The actual measure of each root canal was performed and then the samples were embedded into a mixture of alginate, used as a conducting medium, where electronic measurements were taken with apex locator before and after preflaring of the canals with Gates-Glidden drills in descending order (#4, #3, #2). Measurements obtained by electronic method were then compared with the actual measurement of the root canal. The results were tabulated and submitted to the Student t test. Results: The results show that there was no statistical significance (p<0.05) between the readings before and after preflaring. Readings closer to the foraminal ending occurred in the group after preflaring with Gates Glidden. Conclusion: It was concluded that preflaring with Gates Glidden drills were not able to influence significantly the accuracy of apex locator in determining the exact working length.

Análise comparativa de dois localizadores apicais eletrônicos na definição do comprimento de trabalho na terapia endodôntica: estudo in vitro / Comparative analysis of two electronic apex locators in working length determination at endodontic therapy: an in vitro study

Introdução: A terapia endodôntica é cercada de etapas que, quando bem realizadas individualmente, contribuem para o sucesso. Uma delas é a odontometria, que busca a mensuração do comprimento real do dente, limitando a ação do operador nos procedimentos de instrumentação e obturação, com vistas a evitar danos aos tecidos periapicais e favorecer o reparo da área. Objetivo: Avaliar in vitro a confiabilidade de dois localizadores apicais eletrônicos (Root ZXII® e Propex II®) na obtenção do comprimento de trabalho comparados às medidas visuais. Material e métodos: Realizaram-se acesso cirúrgico e preparo cervical em 40 dentes humanos unirradiculares, e uma lima tipo Kerr #10 foi introduzida até sua extremidade ser observada na saída foraminal com aumento de 8 vezes. Então, posicionou-se o stop de borracha no bordo incisal e mediu-se esse comprimento com uma régua endodôntica milimetrada, obtendo-se o comprimento real do dente (CRD). Os dentes foram inseridos em uma base experimental composta de esponja vegetal embebida em solução de cloreto de sódio a 0,9%. Efetuaram-se as medições eletrônicas tendo como critério a localização do forame de acordo com a marcação de ápice dos aparelhos Root ZXII® e Propex II®. Resultados: O localizador apical Root ZXII® obteve índice de acerto de 93%, e o Propex II®, de 90%. Não houve diferença estatística entre os aparelhos testados (p = 0,05). Conclusão: Ambos os aparelhos demonstraram índices de acerto aceitáveis para a sua utilização na clínica.

Introduction: Endodontic treatment comprises individual steps that should be effectively performed in order to achieve therapeutic success. Among these steps is the determination of the real tooth length, which prevents damage to the periapical tissues during instrumentation and obturation, due to restrict the operator action, favoring tissue repair. Objective: The present study aimed to evaluate in vitro the reliability of two electronic apical locators (Root ZX II® and Propex II®) in working length determination, compared to direct visual measurement. Material and methods: Forty single-rooted human teeth were selected; the pulp chamber was accessed and a size 10 Kerr file was inserted into the canal until its tip was visible at the apical foramen with x8 magnification. At this point, a rubber stop was placed on the file, at the incisal edge, and this length was measured with an endodontic ruler, therefore, recording the real tooth length (RTL). Then, the teeth were embedded in a vegetable sponge (loofah) base, soaked in saline solution. Electronic measurements were carried out using Root ZX II® and Propex II® locators, until an ?Apex? reading was observed. The measurements obtained by the different methods were compared. Results: Root ZX II® apical locator showed 93% of correct readings, while Propex II® locator was correct in 90% of the measurements. No statistically significant difference was observed between the two apex locators tested (p = 0.05). Conclusion: Both apex locators showed an acceptable percentage of correct readings and, therefore, may be recommended for clinical use.

Accuracy assessment of electronic apex locators in dental clinical practice / 实用口腔医学杂志

Objective:To observe the accuracy of electronic method(EM), handing method(HM) and X-raying method(X-RM) in measuring root canal working length. Methods:Total 31 root canal in vivo were measured with HM, X-RM and EM(by the electronic apical locators-Root ZX and Raypex-5 respectively), and the data were compared with the actual root canal working lengths which were obtained from the sectional view's constrictions of the extracted teeth by magnifying glass. Results:Accuracy of working length measured by Raypex-5 was 93.55%, Root ZX was 87.10%, HM was 35.48%, and X-RM was 48.39%. Significantly statistical differences (P