The aim of this study was directed to rate the quality of different
Engine-driven retreatment files: ProTaper Retreatment files, Wave One system and OneShape system in removal of different filling materials. Material and methods: Nighty-six freshly extracted mandibular first molars were prepared with universal ProTaper rotary files till size F3 then categorized into two main groups (I and II) on the basis of type of material used in obturation. Group I: obturated with Gutta-percha, Group II: obturated with EndoREZ. Each One of them was categorized into three subgroups : sub group A, B and C on the basis of the system use (16 each), Subgroup A: using ProTaper Universal retreatment system, Subgroup B: using Wave One file, Subgroup C: using One Shape. Each subgroup was divided into two divisions according to the use of solvent or not (8 each). The residual obturating material was evaluated by the use of the stereomicroscope. Results: there was a significance unlikeness among tested groups, subgroups and subdivisions in the percentage of the residual obturating material Conclusion: Protaper retreatment instruments and Wave One file remove more filling material in comparison with OneShape file, regardless the amount of residual gutta percha filling material ,it was greater than with EndoREZ, Retreatment without the use of solvent was significantly faster and more effective than with solvent.