الفهرس | Only 14 pages are availabe for public view |
Abstract In recent years, patients increasingly expect to retain their natural teeth and are often reluctant to have their natural teeth extracted. Root canal retreatment might offer patients a second chance to save their teeth. The success of nonsurgical root canal treatment is dependent on cleaning and shaping of the root canal space, technical quality of the root canal filling, and an adequate coronal restoration. Since the main cause of endodontic failures was found to be inadequate root-filling quality (1), therefore the role of root canal retreatment was found to be crucial for enhanced treatment outcomes and better success rates. The alternatives when root canal treatment fails are conventional root canal retreatment, surgical retreatment or extraction. Among these alternatives, nonsurgical retreatment offers a more favorable long-term outcome than the peri-radicular surgery (2). Many techniques have been advocated for the removal of gutta-percha from the root canal system including ultrasonic instruments, lasers, hand files, and hand files combined with heat or chemicals. Removal of gutta-percha by conventional methods by using hand files from the root canal system might be difficult and time-consuming. For this reason, rotary nickel-titanium (NiTi) files have been proposed for the removal of the root canal filling, and in recent years, a number of retreatment file systems were developed. In the last few years, several retreatment systems were introduced to the market. These systems consist of 2 or more files. Recently single file concept in cleaning and shaping of root canal was introduced to decrease time the consumption. Among those systems are one shape and wave one. Therefore for the purpose of decreasing the time consumed in retreatment this study was conducted as it was thought that evaluation of the efficiency of single rotary NiTi file system in removal of gutta pecha is of a value. This is from the prospective of effect on canal curvature and the surface topography of the files used. |