Which is the best instrument for removal of guttapercha from root canal ?

Protaper Universal Files are the best when it comes to removal of gutta percha from the root canal during re-treatment cases. In fact it is much more efficient than the Protaper Retreatment Files. Both these files extrude equal amount of Gutta percha into the periapex during the standardized procedure.
Ref: J Appl Oral Sci. 2010;18(6):542-5