Apically extruded debris in filling removal of curved canals using 3 NiTi systems and hand files

Abstract

The aim of this study was to assess the amount of apically extruded debris during filling removal with WaveOne Gold (WOG), ProTaper Universal Retreatment (PTR), D-RaCe Retreatment (DRR) or hand files (HF), to compare the working time during filling removal, and to describe failures of NiTi instruments. Forty mesiobuccal roots of maxillary first molars were prepared with WOG Primary, obturated and divided into 4 groups (n=10), according to the instruments used: WOG, PTR, DRR or HF. Distilled water was used as irrigant and the extruded debris were collected in Eppendorf tubes and dried. The amount of extruded debris was determined by subtracting the final from the initial weight. The time of filling removal for each canal was recorded and the instruments used were analyzed pre and post-operatively by SEM. Kruskal-Wallis and Dunn's test analyzed extruded debris data and ANOVA, followed by Tukey's test, compared the working time data (α=0.05). Instrument deformation and fracture were described. WOG produced significantly less debris compared with HF and DRR (p<0.05), and similar to PTR (p>0.05). HF, PTR and DRR showed no significant difference (p>0.05). Working time in HF group was significantly higher than others (p<0.05). SEM analyses showed, from the 18 instruments evaluated, 3 fractures and 10 deformations. All instruments tested caused debris extrusion. WOG was associated with less extrusion than DRR and HF. Filling removal with HF was slower than with the other instruments. All NiTi systems presented fracture and deformation.

Apically Extruded Debris following Programmed Over Instrumentation of Curved Canals with Three Nickel Titanium Rotary Instruments

“…The quantification of extruded debris was done in the laboratory by using an experimental model well-defined to collect the debris, in addition to an analytic balance of high sensitivity used. Contrary to most of the published studies where evaluation of apical extrusion was performed with a WL of 1 mm from the apical foramen, 10,11,30,31 the instrumentation of the canal system was accomplished at the foramen and beyond, which might limit comparison with previous studies. Most studies related to this subject have calculated the amount of extrusion of debris after instrumentation at the WL which corresponds to the apical constriction.…”

“…Most studies related to this subject have calculated the amount of extrusion of debris after instrumentation at the WL which corresponds to the apical constriction. 10 To the investigators' knowledge, no study has reported extrusion of debris beyond the foramen.…”

“…In the present study, evaluation of the apical extrusion of debris produced by continuous rotary-file systems versus single-file reciprocating system demonstrated that all instruments created apical debris extrusion, in agreement with the previous studies. 1,5,10,29,[31][32][33] Dincer at al reported that continuous rotary systems extruded more debris than reciprocating systems (dried extruded debris) at the WL. 31 In addition, Karataş et al specified that WOG system produced less debris than the continuous rotation systems such as the ProTaper Gold and ProTaper Universal systems.…”

“…ProTaper Next and WaveOne Gold have been currently investigated regarding the amount of apical extrusion debris identified in their applications. 9,10 Other file systems have limited information concerning this subject, such as the BT Race system. 11,12 The ProTaper Next system (PTN; Dentsply Maillefer, Ballaigues, Switzerland) is used with continuous rotation.…”

Evaluation of Three Ni-Ti Systems in Retreatment of Curved Root Canals Obturated by Gutta-Percha With iRoot SP

“…Numerous studies presented that some mechanical nickel-titanium (Ni-Ti) instruments, in particular rotary and reciprocating systems, exhibited e ciency in root canal retreatment [11,12,13,14,15,16,17]. In these studies, Protaper Universal Retreatment (PTR) system, Waveone Gold (WOG) system, and Reciproc Blue (RB) system are regularly applied to curved root canal retreatment.…”