International Journal of Dental Sciences and Research
ISSN (Print): 2333-1135 ISSN (Online): 2333-1259 Website: Editor-in-chief: Marcos Roberto Tovani Palone
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International Journal of Dental Sciences and Research. 2015, 3(4), 82-86
DOI: 10.12691/ijdsr-3-4-1
Open AccessArticle

Assessment of Apical Anatomy with Reference to Accuracy of Working Length Determination Methods in Permanent Mandibular First Molars

Yaparathna YMKN1, Jayasinghe RD2, Abeysekara WPMM3, Fonseka MCN4, and Wettasinghe KA4

1Registrar in Restorative Dentistry, Faculty of Dental Sciences, University of Peradeniya, Sri Lanka

2Department of Oral Medicine and Periodontology, Faculty of Dental Sciences, University of Peradeniya, Sri Lanka

3Ministry of Health, Sri Lanka

4Department of Restorative Dentistry, Faculty of Dental Sciences, University of Peradeniya, Sri Lanka

Pub. Date: June 02, 2015

Cite this paper:
Yaparathna YMKN, Jayasinghe RD, Abeysekara WPMM, Fonseka MCN and Wettasinghe KA. Assessment of Apical Anatomy with Reference to Accuracy of Working Length Determination Methods in Permanent Mandibular First Molars. International Journal of Dental Sciences and Research. 2015; 3(4):82-86. doi: 10.12691/ijdsr-3-4-1


The mandibular first molar (MFM) is considered a vital tooth in establishing occlusion in the permanent dentition. As it is a tooth prone to caries its morphology is vital in restorative, endodontic and surgical aspects in dentistry. Accurate working length (WL) determination is considered an essential for the success of root canal therapy. Methods of WL estimation include detecting the apical constriction by tactile means (apical boundness), using a periapical radiograph or by means of an electronic apex locator (EAL). The objective of this study was to assess the accuracy of different WL assessment methods in comparison to the actual length of the tooth assessed by visualising the apical constriction of MFMs. Access cavities were prepared in 188 extracted permanent MFMs, mounted on alginate and suitable K-file was passed though each root canal to determine the apical constriction. WL was determined with a third generation apex locator with a proven accuracy (Root ZX Mini J Moritacorp. Japan). These teeth were assessed both with analog and digital radiography to assess the position of the files on the radiograph. Finally the teeth were assessed with a 2.5X magnification to visually locate the apical constriction (actual length) of each root canal. The mean actual length of mesio-buccal canal was 20.06mm, mesio-lingual canal was 19.97 mm, disto buccal canal was 19.81 mm and disto- lingual canal was 19.40 mm. Accuracy of EAL is 98.5%. There was no significant difference between the accuracies of 1st bound, film based and digital radiography. Thus the most accurate method in WL determination is the EAL.

lower first molar root canal configuration digital radiography

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