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.

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.

Comparative evaluation of apically extruded debris using three different thermomechanically heat treated file systems with two different motions: An in vitro study.

Introduction and Aim: Postoperative inflammation and endodontic failure occur due to apical extrusion of debris. The purpose of this in vitro study was to assess the amount of apically extruded debris during the root canal preparation using rotary and reciprocating nickel-titanium instrumentation systems. Materials and Methods: The mesiobuccal canals of seventy five mature, human mandibular molars were randomly divided into three groups (n = 25 teeth/group). Each group was instrumented using one of the three different instrumentation systems: Hyflex EDM (HEDM) rotary file, Flexicon X7 rotary, and Flexicon X1 reciprocating files. The canals were irrigated using distilled water. The debris extruded apically was collected in preweighed Eppendorf tubes and assessed with an electronic balance and compared. Statistical Analysis: Data were statistically analyzed by one-way analysis of variance and the intergroup comparison with single factor ANOVA. Results: The Flexicon X1 reciprocating system showed the maximum amount of apical extrusion of debris among all the groups. The least amount of debris was observed in Flexicon X7 rotary instrument (P > 0.05). Conclusion: Flexicon X7 rotary extruded significantly lesser amount of debris than Flexicon X1 reciprocating and HEDM rotary file systems.

A comparative evaluation of cyclic fatigue resistance of FlexiCON (Edge Endo) files in rotary versus reciprocating motion at various curvatures - An in vitro study.

AIM: The aim of the study to compare the cyclic fatigue resistance of FlexiCON (Edge Endo) files in rotary versus reciprocating motion in coronal, middle, and apical curvature of the simulated artificial canal. MATERIALS AND METHODS: A total number of 36 new files, 25 mm length of ISO size 25 at the tip and a taper of 0.06, were used for the study and divided into two groups of 18 files each. Group I: FlexiCON X3, was used in a rotary motion and Group II: FlexiCON X1 was used in a reciprocating motion. Cyclic fatigue testing was conducted in a custom-made device that allowed for a reproducible simulation of a curved canal. The canal system, which comprised two adjustable stainless steel blocks, had a 60° angle of curvature and 3 mm width. The groups were further divided into three subgroups with six files in each, representing apical curvature (Group Ia/IIa), middle curvature (Group Ib/IIb), and Coronal curvature (Group Ic/IIc). Using X-Smart plus motor, files were used in rotary and reciprocating mode and the number of cycles to failure was recorded. STATISTICAL ANALYSIS: Data were analyzed using ANOVA and Post hoc followed by Dunnett's test and unpaired t-test using Statistical Package for the Social Sciences 16 version. RESULTS: FlexiCON X1 reciprocating files showed the maximum cyclic fatigue resistance at coronal curvature (1936.50 ± 1.09) followed by middle (1514.50 ± 1.07) and apical curvature (1487.50 ± 6.75), while FlexiCON X3 rotary files showed the maximum cyclic fatigue at the middle curvature (1106.00 ± 4.21), followed by coronal (920.00 ± 1.16) and apical curvature (757.00 ± 5.34). The statistical analysis revealed a statistically significant difference (P = 0.001) between the two groups. CONCLUSION: FlexiCON X1 reciprocating files showed better cyclic fatigue resistance at coronal, middle, and apical curvature compared to FlexiCON X3 rotary files.