Effectiveness of the GentleWave System in Removing Separated Instruments

• We evaluated the efficiency of the GentleWave System to remove separated instruments (hand steel files) from the apical third and the midroot regions of the root canal system.
• The GentleWave System cleaned approximately 61% and 83% of separated instruments when broken in the apical third and middle regions of mesial roots and mesiobuccal roots of mandibular and maxillary molars.
• The average treatment time was 10 minutes 44 seconds.
• The success of the removal of separated instruments with the GentleWave System was achieved without the aid of a secondary instrument, in the presence of irrigants, and while maintaining the dentin integrity.
• Of interest is to evaluate the cleaning efficiency of the GentleWave System around and beyond the separated instrument and in cases of nickel-titanium separated instruments.

IntroductionA separated instrument in a root canal system has the potential of severely affecting the outcome of endodontic therapy. This study evaluated the effectiveness of the minimally invasive GentleWave System (Sonendo Inc, Laguna Hills, CA) in removing separated stainless steel endodontic files from the apical and midroot regions of molar root canals.MethodsThirty-six extracted human molars were accessed, and the glide path was confirmed to the apex. ISO #10, #15, and #20 K-file fragments of 2.5-mm length were separated at the apical (n = 18) or midroot (n = 18) region of the molars by engaging a weakened file with downward pressure. During analysis, the teeth were divided into 2 curved groups based on the curvature of the root (<30° and >30°). The success rate of instrument removal and the treatment time were noted. Statistical comparison was done with the Fisher exact test and independent 2-sample t test (P < .05).ResultsThe overall success rate of instrument removal when the separated files were engaged in the apical region was 61%, and for the midroot region, it was 83%. Less curved canals (<30°) showed a 91% success rate (n = 24), whereas canals with an angle of curvature greater than 30° showed a 42% success rate (n = 12). The median treatment time for instrument retrieval was 10 minutes 44 seconds.ConclusionsThe results revealed that the GentleWave System is effective in retrieving separated instruments while conserving the dentinal structure.