To Compare The Effects Of Different Methods For Removing Complex Root Canal Residual Fillings

Objective: To assess the amount of residual material in the root canal after using Pro Taper Universal Retreatment files alone and supplemented with XP-endo Finisher R,TFA,or Psaaive Ultrasonic Irrigation by CBCT scanning and Mimics software.Methods: Forty-five oval single-canal premolars were prepared with Protaper Universal system to F2 and filled with Warm gutta-percha.The samples were randomly divided into three groups: XP-Endo Finisher R group,TFA group and passive ultrasonic ablation group.In stage one,Protaper Universal Retreatment files(D1-D3)were used to remove most of the filling in the root canals,and in stage two,XP-Endo Finisher R,TFA and Psaaive Ultrasonic Irrigation were used to remove residual filling.All samples were placed into a silica gel model,scanned by cone beam computed tomography,and the amount of opaque radiography in the root canal was calculated by Mimics 20.0 software.Statistical analysis was performed using Kruskal-Wallis,Dunn’s and Mann-Whitney tests,the test level α=0.05.Results: There was no significant difference in the volume of initial filling materials among the three experimental groups(P=0.96),and the additional use of Psaaive Ultrasonic Irrigation did not significantly improve the removal of residues compared with PTUR alone(P>0.05),however,both XP-endo Finisher R and TFA significantly improved residue removal(P< 0.05)and there was no statistical significance between them.Conclusion: The XP-Endo Finisher R and TFA systems are more effective at removing filler material through mechanical wear in contact with the root canal wall than using passive ultrasonic shock to activate the rinse solution.Additional use of these three devices with different motion mechanics can improve the removal of residual fillings.However,no device can completely remove the filling material from the root canal.