ارزيابي دقت يك نوع Electronic Apex Locator در تعيين طول دندان هاي شيري (In-vitro)

An evaluation on the accuracy of an electronic apex Locator (EAL) in the determination of working length inprimary teeth (In-vitro

بيان مساله: راديوگرافي رايجترين روش محاسبه طول كاركرد به شمار مي رود ولي به دليل محدوديتها و مشكلاتي كه دارد، روش ايده آلي محسوب نمي گردد؛ بويژه كاربرد آن در كودكان به دليل خطرات تابش اشعه، مشكلات انجام تكنيك آن بخصوص در كودكان خردسال و غير همكار و سوپرايمپوزيشن جوانه دندان دائمي بر روي ريشه دندانهاي شيري و... مشكلات عديده اي را فراهم مي كند. هدف مطالعه حاضر با هدف ارزيابي كاركرد يك نوع Electronic Apex Locator (EAL) در تعيين طول دندانهاي شيري انجام شد. روش بررسي در اين مطالعه تجربي (In-vitro) 96 كانال از دندانهاي شيري كشيده شده كه حداقل دو سوم طول ريشه آنها باقي مانده بود، با شرط عدم وجود انسداد در كانال ها، درمان ريشه قبلي و پرفوراسيون كف پالپ شامبر بررسي شدند. طول نمونه ها توسط راديوگرافي نيز تعيين شد. معيار مقايسه طولهاي به دست آمده از Raypex 4 و راديوگرافي نيز طول واقعي كانال ها بود كه از طريق مشاهده مستقيم تعيين گرديد. EAL مورد استفاده در مطالعه Raypex 4 از دستگاه هاي جديد نسل چهارم (Ratio Type) بود. اطلاعات به دست آمده با استفاده از آزمونهاي آماري Chi-Square و Pearson Correlation مورد تحليل قرار گرفت. نتيجه گيري به نظر مي رسد با توجه به ايمني، بدون درد بودن، كاربرد راحت و سريع و قابل مقايسه بودن دقت Raypex 4 EAL با راديوگرافي، استفاده از آن براي تعيين طول دندانهاي شيري كودكان مفيد باشد.

Statement of Problem: Radiography is the most common technique in working length determination, however, because of its limitations is not considered as an ideal technique. Its application, particularly for children due to radiation hazards, technical problems in young and unco-operative children and the superimposition of permanent teeth bud on primary teeth root, lead to numerous problems. Purpose The goal of this study was to evaluate the accuracy of an electronic apex locator (EAL) in working length determination of primary teeth. Materials an‎d Methods In this in-vitro study 96 canals of the extracted primary teeth, with at least 2/3 of the root length remained, were investigated. There were no obstructed canal, previous root canal therapy and perforation of pulp chamber floor. All working lengths were also measured by radiography. The results of Raypex 4 and radiography were compared with actual root canal lengths determined by direct observation. The applied EAL, in this study was called Raypex 4, a new device belonged to the fourth generation (Ratio Type). The results were analyzed by Chi-Square and Pearson correlation statistical tests. Results The accuracy of Raypex and radiography were 61.5% and 63.5%, respectively. The differences between Reypex 4 root canal length measurements and those of direct observation were not significant (P=0.08), but such difference between radiography and direct observation was statistically significant (P=0.01). The diameter of the apical foramen (the site of canal opening) did not affect on Raypex 4 accuray (P>0.05). Conclusion Considering the acceptable safetyness, Painlessness, simple and rapid application and an accuracy comparable to that of radiography, the use of Raypex4 EAL for the measurement of primary teeth length is suggested.