The Efficacy of D-Race and Different NiTi rotary Instruments in the Removal of Root Canal Filling Materials

摘要

Although endodontic treatment has high success rate, but endodontic treatment can fail.Several methods were tried to remove root filling material. The aim of this study is to evaluate theefficacy of D-Race retreatment file with different NiTi rotary instruments (RECIPROC blue (RB),ProTaper NEXT (PTN), ProTaper Gold (PTG)) in the removal of root canal filling materials. Sixty mandibular premolar teeth with straight canal were selected. Teeth were instrumentedwith PTN in sequence (X1-X4) then obturated by using single cone with GuttaFlow 2 obturationmaterial. The teeth were divided into four groups for retreatment: D-RaCe, D-RaCe+ RB, D-RaCe+PTN, D-RaCe+ PTG. The specimens were sectioned longitudinally and inspected by digitalStereomicroscope at 12.5X magnification. Statistical analysis was performed by Kruskal-Wallis test(P>0.05). A non-significant difference was found between groups (I, II, III, IV) at all levels (Apical, Middle,Coronal) (P>0.05). In each group a non-significant difference between levels was found (P>0.05). The highest remnant was found at the coronal level of group I (9.83 %), while the lowestremnant was found at coronal level of both groups III&IV (0%). Although shaping instruments with different motions and designs were used, the additional useof shaping instruments (RECIPROC blue, ProTaper Next, ProTaper Gold) with D-RaCe systemdidn’t enhance root filling material removal significantly.