Study of endodontic working length of Korean posterior teeth

Abstract

Objectives:The aim of this study was to investigate average working lengths of Korean posterior teeth and evaluate validity of endodontic file length. Materials and Methods:The endodontic working length of the posterior teeth of 670 Korean patients were measured than each mean value and standard deviation were investigated than the frequency deviation and standard deviation per each length were calculated. Results: Among the canals of premolar, 66.5% of canal length was marked under 20 mm by endodontic working length and 95.4% could be measured under 22 mm and Among the canals of molars, 95.5% of canal length was marked under 20 mm endodontic working length . Conclusions: With the result of measurement of endodontic working length of premolars of Korean, it suggested that 23 mm endodontic file is more proper than the 21 mm and 25 mm file on the market. since these Ni-Ti files should be mounted on a handpiece and can' t apply precurvature. In clinical procedure of endodontic treatment, the time for patients to keep their mouth open is longer than in any other treatment. If the time of mouth opening increases, patient will feel discomfort and side-effects like temporo-mandibular joint disease might occur. 6,7 Using long instruments will also give difficulties during the treatment procedures for the operator too.The lengths of the endodontic instruments are designed to be based on the length of the tooth. There are several methods for measuring these lengths of the teeth. 8 There are methods like, measuring directly from extracted tooth, surveying from the radiographic films or by measuring the working length of the tooth. 9 This method of measuring working length of the tooth can be done by measuring the length of the extracted tooth, using radiographic references or by using electronic working length measuring instruments. In vivo study, the radiographs are not always reliable because they can show considerable deviations depending upon the angles of the X-ray cone. 10 The apical constriction of the the root also does not coincide with the anatomic apex. 8,11,12 It is deviated linguo-buccally or mesio-distally from the root. If the exit deviates bucco-lingually, it is very difficult to locate accurately the position of the apical foramen using only roentgenograms, even with multidirected angles. 13The electric apex locator (EAL) machine has attracted a great deal of attention because it operates on the basis of the electrical impedance rather than by a visual inspection.13 EALs help to reduce the treatment time and the radiation dose, which may be higher with conventional radiographic measurements. In addition, EALs were reported to be an accurate [14][15][16][17][18] and reproducible method as the newest third generation type and can acknowledge a root perforation.International standard follow the average tooth lengths of caucasian people. 9,19,20 Although there were reports on the average tooth length of caucasian people, few information on the differences of canal lengths between the races is available.Theref...

A Rare Case of Nonsyndromic Generalized Radiculomegaly with a Literature Review

“…Currently, there are three standard lengths available for endodontic files: 21 mm, 25 mm, and 31 mm. In addition, various studies have been conducted to improve the intraoral accessibility of instruments for endodontic treatment [27]. Thus, modified endodontic files and obturation techniques have been developed (Pace et al, 2011).…”

Non-surgical endodontic treatment of maxillary first molar with large size and curved canal: a case report

“…Three standard lengths are available as 21 mm, 25 mm, and 31 mm, these lengths usually meet the majority of endodontic cases .The studies showed that there are differences in root canal lengths among populations. It has been found that the tooth lengths in Asians were shorter than Caucasians (Kim E et al 2005), and there was the difference in root canal lengths between Asians and western population with the latter having longer teeth (Kim J et al 2010). Variation in size, form and morphology of the teeth resulted in anomalies such as macrodontia, microdontia , hyperdontia, hypodontia, taurodontism and dens in dente.…”