Purpose: to investigate the ability to use XP for nonsurgical endodontic retreatment and to compare its performance with 2 other single-file systems with regard to the amount of remaining root filling material after retreatment, operation time, and the amount of apically extruded debris after instrumentation
•N = 90 extracted single canal human mandibular incisors
•Excluded teeth with open apices, resorptive defects, caries, root fillings, cracks, calcifications, initial apical diameter > #25, apical curve > 10°
•PA radiographs taken in MD and BL direction and CBCT scans taken
•60 teeth with type I Weine configuration that are similar in length and canal shape and apical diameter were divided into 3 groups (n = 20)
•File systems are:
•Hyflex EDM “one file” (EDM) (Coltene/Whaledent, Alstatten, Switzerland)
•WaveOne Gold (WOG) (Dentsply Sirona, Ballaigues, Switzerland)
•XP Shaper (XP) (FKG, La Chaux de Fonds, Switzerland)
Treatment Procedure:
•Incisal edge flattened to create a reproducible ref poin
•Root canals prepared with Vortex Blue up to size 30/04 and obturated by WV and AH+ sealer then access sealed with cotton and TF. RG taken.
•Each tooth coded and kept in humidity for 30-45 days before retreatment procedure
Re-Treatment Procedure:
•Each group allocated to one of the single file rotary systems (n = 20) 1.WOG group: primary file size 25/07 (reciprocating motion) 2.EDM group: size 25/08 3.XP group: size 27/01
•All procedures done by single endodontist under DOM and tooth/instrument temp maintained
•Once WL achieved, 10 strokes applied followed by visual examination of the canal; if GP present repeat
•Debris were collected and examined
•CBCT scan taken pre-op, after obturation, after removal of GP and after retreatment procedure and remaining RCF material was calculated
Results:
•4 samples were excluded
•Sig difference among groups in operating time (XP > EDM > WOG)
•% of remaining RCF material was greater with WOG 25% > EDM > XP
•No diff in amount of extrusion
•When the speed was increased to 3000 rpm, XP was successfully able to penetrate and remove gutta-percha (speed was based on pilot studies)
Conclusion:
XP appears to be a suitable instrument for endodontic retreatment when operated at a higher speed (3000 rpm). It was the most efficient in gutta-percha removal from the canals followed by EDM and WOG.
