مقایسه اثر اینسترومنتیشن با دو روش مختلف بر قطر کانال و عاج باقیمانده در محدوده فضای Post Room ریشه اصلی دندان‌های مولر

Background and Purpose: Since molar main canal preparation faciliates a good apical obturation and provides necessary room for “post” placement. This study focuses on the outcome of two different instrumentation methods in canal diameter and remained dentin. Materials and Methods: Main canal of 60 upper and lower molars prepared in 4 groups using step back (SB) and passive step back (PSB) techniques gross sections were made in molar roots in 5,7,9,11 millimeters from apical foramina and measurements were done. Results: Çanal diameter and width of remained dentin of the instrumented canals were measured by two methods. Results show no significant difference between the methods, using “T test”. Çonclusion: Both SB and PSB methods are recommended considering “Post” room preparation. Regarding minimal remained dentin in danger zone, care must be taken not to reduce the dentin width to less than one millimeter and not to produce strip perforation.