Sample and methodology: sample of study comprised 50 teeth which need endodontic treatment and meet all study's. criteria. Method of study was seflcontrol clinical trial. Treatment technique follows procedure of "ProTaper for hand use". Treatment result were followed up for 3 months. Goal of study is to elavaluate treatment result of irreversible pulpitis using "ProTaper for hand use". Results:At 1 week post-treatment: 96 percent of teeth got good result, 4 percent of teeth got average result, no teeth got bad result. At 3 month post-treatment: 92 percent of teeth got good result, 8 percent of teeth got average result and no teeth got bad result. Conclusion: "ProTaper for hand use" system makes cleaning and shaping of root canal better. Risk of treatment failure is higher in teeth whose apex were wide or were widened by treatment.