دراسة مخبرية للمادة القنوية الحاشية على فعالية اعادة المعالجة اللبية القنوية الآلية باستخدام نظام ال Pro-taper

Background& Objective: This study aimed to asses of role of obturation material (zinc oxide and eugenol cement with gutta-percha points, Resilon) on the efficiency of endodontic retreatment with Pro-taper system of the following respects: the degree of cleanliness of the canal, complications, working time. Materials & Methods: The sample of study consisted of Forty recently extracted, straight single-rooted, premolars prepared with Pro-Taper system in crown down technique and filled using cold lateral compaction. The sample was randomly divided into 2 equal groups of 20 teeth each, according to the root canal filling material used :(Group1: gutta-percha and zinc oxide and eugenol Sealer),(Group2: Resilon points). After root canal filling, the temporary restorative material was placed, and the teeth were stored at 37oC for a month .Then, it were retreated with Pro-Taper Universal System retreatment files without using any solvents. After that it were examined by X-ray. In addition, perforations, blockages, or ledging were noted. The time required to remove filling material was recorded. All images for each canals were inserted to the computer. The statistical analysis of the results using the Kruskal-Wallis test, Kai –Square test, ANOVA test and T- student test(P≥0.05). Results: Significant differences were not found for degree of cleanliness of the canal and complications(p>0.05), but removal of Resilon was faster than gutta-percha because it was statistically significant difference(p<0.05). Conclusions: The Pro-taper system has the same effectiveness in the removal of obturation material in both groups whether (gutta-percha groups) or (Resilon groups) , but removal of Resilon was faster than gutta-percha