The assessment of the filling material remaining on root canal walls after using protaper universal rotary retreatment system with or without a solvent

The purposes of retreatment are to eliminate the cause for failure of initial endodontic treatment and to preserve the tooth as well. The aim of this study is a comparative evaluation of efficacy of Protaper rotaty retreatment instruments for gutta-percha removal with or without solvents specific both to the sealer and gutta-percha. Materials and methods: Forty single-rooted extracted teeth were randomly divided into 4 groups according to different methods of retreatment. The teeth were prepared with Protaper Universal system (Dentsply-Maillefer, Ballaigues, Switzerland) and filled using lateral condensation of gutta-percha and AH Plus (Dentsply DeTrey, Konstanz, Germany). All root canal fillings were removed using Protaper Universal Retreatment system (Dentsply-Maillefer, Ballaigues, Switzerland). During the retreatment procedure, in group 1 Resosolv (Pierre Rolland, Merignac, France) was used; in group 2 eucalyptol was used, in group 3 Endosolv E (Septodont, Paris, France) was used and in group 4 no solvent was used. The times required for retreatments and radiographycal evaluation after retreatment were recorded. Results: All root canals showed filling material remnants and group 1 with specific solvent for AH Plus recorded the shortest time. Conclusions: Although it is not possible to eliminate the entire filling material on the canal walls, the duration of retreatment was reduced by the use of a solvent specific to the sealer compared with a gutta-percha solvent or no solvent.