A new method and apparatus for measuring root canal length.

Hasegawa, Kiyoshi; Hzuka, H.; Takei, Mitsuhisa; Goto, Naohisa; Nihei, Masahide; Ohashi, Masayoshi

doi:10.2334/josnusd1959.28.117

Cited by 19 publications

(5 citation statements)

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“…The canal does not need to be dried before modern EALs are used because they can work in the presence of electrolytes. [10,33,36,37] Therefore, practitioners have widely accepted modern EALs because they have high reliability, have high accuracy and reduce the number of radiographs for required WL determination.…”

Section: Discussionmentioning

confidence: 99%

Evaluation of the Use of Sixth Generation Apex Locators as a Diagnostic Tool to Detect Root Perforations

Srivastava¹,

Jain²,

Bagchi³

et al. 2015

Int. Jour. of Dent. and Med. Spec.

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Aim: The sixth generation apex locators served as an efficient diagnostic tool for detecting root perforations as these are based on the principle of impedance rather than the conventional gradient method. However, their diagnostic accuracy not evaluated well. In the existing study, we assessed and compared the efficacy of two apex locators for diagnostic perspective. Materials and Methods: A total of 32 extracted teeth were perforated and mounted using alginate (Alginate Impression Material, 3M ESPE, USA). Two different apex locators-Raypex ® 6 Apex Locator (VDW) and ProPex Pixi (Dentsply, USA) were used to detect the intentionally created root perforations (i.e., distance from file tips to external outline of the root surface). The two apex locators measured the same root perforations and compared statistically. Results: The mean distance from file tips to external outline of the root surface was found significantly different and lower (59.9%) in Raypex ® 6 Apex Locator as compared to Propex Pixi (mean ± standard deviation: 0.39 ± 0.04 vs. 0.16 ± 0.02, t = 30.57, P < 0.001). Conclusion: We found Raypex ® 6 Apex Locator better for root perforations.

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Section: Discussionmentioning

confidence: 99%

Evaluation of the Use of Sixth Generation Apex Locators as a Diagnostic Tool to Detect Root Perforations

Srivastava¹,

Jain²,

Bagchi³

et al. 2015

Int. Jour. of Dent. and Med. Spec.

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“…A high frequency (400 kHz) wave measuring device, the Endocater (Yamaura Seisokushu, Tokyo, Japan) was introduced by Hasegawa et al. (1986).…”

Section: The Second Generationmentioning

confidence: 99%

Electronic apex locators

2004

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The accuracy of three electronic apex locators (EALs) (Justy II, Root ZX, and Neosono Ultima EZ) is evaluated, together with the concordance of the measurements obtained by two different operators. Twenty single-root human teeth were used, sectioning the crown to gain access to the root canal. A first operator (A) determined the reference (or control) length (corresponding to the actual length) for each tooth, after which all teeth were measured individually and independently by the other two operators (B and C). The results obtained with each EAL and by each operator were in turn compared with the corresponding control length. The statistical analysis of the results showed EAL reliability in detecting the apex to vary from 80% to 85% and 85% to 90% (depending on the operator) for the Justy II and Neosono systems, respectively, whereas reliability was found to be 85% for the Root ZX device. These results, combined with a high interobserver concordance, suggest electronic root canal measurement to be an objective and acceptably reproducible technique.Correct working length determination is the main factor leading to success in root canal treatments. Recent studies (1) have shown the histologic results after endodontic treatment to be superior when instrumentation and obturation are limited to the apical narrowing.However, of the methods currently available for root canal measurement, neither the manual nor the radiologic approaches allow precise localization of apical narrowing. The manual technique obviously depends on the sensitivity of the operator, whereas in the radiologic approach, the calculation of the working length is made with respect to the position of the radiographic apex-which not only does not coincide with apical narrowing or even with the apical foramen (2), but also depends on a series of factors: tooth inclination, film position, length of the beam cone, vertical and horizontal cone angulation, and so forth. Nevertheless, the main inconvenience is that both approaches are entirely subjective and therefore scantly reproducible.Since the pivtotal demonstration by Sunada (3) in 1962 that the electrical resistance between the periodontal ligament and the oral mucosa is a measurable constant, different generations of electronic devices have been developed to measure root canal length. The first-generation (resistance) locators detected the point where the file displaces from within the canal to the periodontal ligament, whereas the second-generation devices were based on the impedance principle. The reliability of these systems was approximately 55% to 75%, although their main inconvenience was the fact that the presence of pus, pulp remains, or irrigating solutions within the canal led to erroneous readings.According to the instructions of the manufacturers, the thirdgeneration dual-frequency and more modern multiple-frequency locators are able to locate the point of maximum root canal narrowing. In this context, a number of studies have been performed in recent years (4 -9) to determine the accur...

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“…These firstgeneration locators provided rather inaccurate measurements as a result of the presence of vital pulp tissue, excessive blood, exudates, or moisture within the canal. Other devices based on electrical impedance were subsequently developed to overcome these drawbacks (7).…”

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confidence: 99%