Comparison of nickel titanium file systems with different angle of taper with rotational motion on amount of apical extrusion of debris

The aim of this thesis study is to compare the amount of apically extruded debris from nickel titanium file systems with different taper angles that rotate. Sixty mandibular premolars with a fully formed apex, no fractures, no previous endodontic treatment, and one root canal were selected. Only premolars with Vertucci type I classification were selected. The selected teeth were divided into three groups as twenty each. In these groups, canal preparation was completed with files with 3 different tapers. Each tooth was prepared with Ni-Ti rotary instrument files in its own group. The files used in the preparation were removed from the root canal each time and cleaned with sterile sponge. After each file use, the teeth were irrigated with 2.5% NaOCl and patency was checked using a #15 K-file in the apical foramen. An apparatus previously described in this study was adopted to collect the extruded debris (82). It was fixed to the cap of an Eppendorf tube through a pre-made hole with the apical 5 mm part inside the tube and the coronal part out. The opennes between the sample and the Eppendorf tube was sealed with Top Dam (FGM, Joinville, SC, Brazil). Next, the Eppendorf tube was inverted and the bottom cut off, creating an opening into which 1.5% agarose gel was poured until the apical root was completely approximated. The apparatus remained in the same position until the gel solidified. The agarose gel provided a matrix to collect debris (82). The weight of the overflowing dentin shavings was determined by subtracting the initial weight (empty tube weights) from the final weight. . One way Anova test was used to determine whether there was a difference in the amount of extruded debris according to the changed tapering of the file system. Bonferroni test was used as Post Hoc test for pairwise comparison of the groups. All instruments were associated with apical debris extrusion. According to the results obtained, there was a statistically significant difference between the groups in terms of the amount of extruded debris (F=469.279, p<0.05). It was determined that the weight of extruded debris was highest in 0.6 Taper file (0.031±0.003) and lowest in 0.2 Taper file (0.008±0.002).