Amani Attia , Ahmed Ghobashy And Salma El-Ashry ,

ABSTRACT
Objective Compare The Effectiveness Of D-Race And Hyflex EDM Files On Removal Of Gutta-percha Sealed With Either Resin-based Or Bio-ceramic Sealer, And To Evaluate The Amount Of Apical Extruded Debris. Methods Forty Eight Extracted Type I Single Rooted Teeth Were Instrumented Using Protaper System. Teeth Were Randomly Divided Into Two Groups (n = 24) According To The Type Of Sealer Into Group I: Bioceramic Sealer And Group II: Resin Based Sealer. After Obturation, Each Group Was Further Divided Into Two Subgroups According To The Type Of System Used In Retreatment (n = 12); Subgroup A: D-Race Retreatment System And Subgroup B: Hyflex EDM Rotary System. Eppendorf Tubes Were Used For Collection Of The Debris Extruded Apically. Each Third Of The Root Canal Was Examined Using Stereomicroscope. Results No Significant Difference Was Found When The Root Canal Was Considered In Its Entirety. Significant Difference Was Found Between Group IA And IIA In The Middle And Cervical Third Of Root Canals. Significant Difference Was Found Between Group IB And IIB In Apical And Cervical Third Of The Root Canal. Conclusion Complete Removal Of Filling Materials Could Not Be Achieved In This Study. Hyflex EDM System Was Effective In Removal Of Filling Materials.