Comparison of the Amount of Debris Extruded From the Apex During Retreatment Procedures Using Several File Systems and to Gauge the Effect of Same and Different Taper on the Debris Extrusion: An In Vitro Study

A BSTRACT Background: To determine the amount of apical extrusion between various file systems during the retreatment procedure and to determine the effect of taper on the same. Materials and Method: Seventy mandibular extracted premolars were taken, and preparation was performed using a Woodpecker file (Woodpecker Medical Instrument Co., Ltd., Guilin, China) (25/0.06). The gutta-percha (GP) was removed from each specimen with H file (#40/0.02) to simulate retreatment in seven groups ( n = 10) using ProTaper Next (PTN;Dentsply, Maillefer, Ballaigues, Switzerland) (PTN) (30/0.07), Reciproc (25/0.08), Hyflex CM (30/0.06), Mtwo (30/0.05), Neoendo flex (30/0.04), Neoendo hybrid (30/0.04), and Flexicon file (30/0.06). The specimens were held with the help of a rubber stopper and put in the Eppendorf tube of volume 4 mL (pre-weighed before retreatment). The debris that was on the root surface of the specimen was washed with distilled water with 1 mL volume, kept in the oven, and then again weighed after 7 days. Results: Apical extrusion was found in the following order: HYFLEX CM (LEAST) < FLEXICON < PROTAPER NEXT < RECIPROC < NEOENDO FLEX < NEOENDO HYBRID < MTWO (HIGHEST). Conclusion: W Hyflex CM and Flexicon files showed lesser extrusion of debris than others.