The effectiveness of three irrigating solutions on root canal cleaning after hand and mechanical preparation

The purpose of this in vitro study was to evaluate and compare the efficacy of three irrigating solutions after hand and mechanical instrumentation. Sixty intact, single, straight-rooted, human teeth were used in this study. They were instrumented using K-files sizes 15 to 50 with hand or mechanical instrumentation. Mechanical instrumentation was with one of two handpieces, the Endocursor or Endolift. Instrumentation time for each file was 1 min. Each change of file was followed by irrigation with 1 mL 1% NaOCl. A flush of 2 mL of one of three irrigating solutions Largal Ultra, Tubulicid Plus or 50% citric acid, was administered at the end of the instrumentation and a final flush of 5 mL distilled water completed the treatment. The specimens were prepared and viewed under the scanning electron microscope. There were no significant differences in the smear layers produced by the three methods of instrumentation. The use of Largal Ultra and Tubulicid Plus removed considerable amounts of the smear layer regardless of the method of instrumentation. The use of 50% citric acid, on the other hand, removed the smear layer only partially whilst producing rather diverse findings.