MethodS: 60 extracted mandibular molars with two mesial canals in one mesial root were selected. All canals were instrumented with rotary instruments (Hero Shaper, MicroMega, France). 45 teeth of 60, instrumented and irrigated by ultrasonics ( EMS, Switzerland) and the rest 15 teeth were not instrumented by ultrasonics, and used as control group. All roots were embedded in clear resin and cut horizantally from 1.5- 2.5 – 3.5 -4.5 mm away from the apex. The quantitiy of dentin debris in isthmus was evaluated under stereomicroscope and recorded.The results were statistically analyzed.
Results: Usage of ultrasonic instruments was found to be statistically effective to clean isthmus in mesial canals of mandibular first molar (p< 0.05).
Conclusion:Ultrasonic instruments are useful to clean the isthmus in mandibular first molars.
Keywords: Ultrasonic irrigation, isthmus