COMPARISON OF 3 DIFFERENT ROTARY RETRETMENT FILE SYSYEM Non-surgical endodonc retreatment is an aempt to re-establish healthy periapical ssues aſter inefficient treatment or reinfecon of an obturated root canal system because of coronal or apical leakage Mtwo Retreatment File R Endo Retreatment File ProTaper D Retreatment File Dentsply D1 size 30, 0.09 taper D2 size 25, 0.08 taper D3 size 20, 0.07 taper VDW R1 (size 25, 0.05 taper) R2 (size 15, 0.05 taper) Micro-Mega Re (size 25, 0.12 taper) R1 (size 25, 0.08 taper) R2 (size 25, 0.06 taper) R3 (size 25, 0.04 taper) GROUP I Mtwo Re- treatment File (VDW, Munich, Germany) GROUP II Protaper D (Dentsply Maillefer, Bal- laigues, Switzer- land) GROUP III R Endo (Micro-Mega, Besancon, France) R Endo Protaper D Mtwo