The PURPOSE of this study was to compare centering ability and apical
canal transportation of K-files (KF), ProGlider (PG) and G-Files (GF) after glide path
enlargement in curved canals using micro–CT. METHODS : 30 canals each were
randomly assigned to KF; GF and PG. Teeth were scanned before and after glide path
enlargement to compare centering ability at three levels: 1 mm (D1) and 7 mm (D7)
from the apical foramen and at the point of maximum root curvature (Dmc).
Transportation was assessed in 8 directions at D1. RESULTS : KF were significantly less
centered than both NiTi groups at D1. At Dmc PG exhibited a significantly more
centered enlargement than both GF and KF, which were significantly similar. At D7,
PG was significantly more centered than KF but there were no significant differences
between GF and KF or between PG and GF (p<0.016). KF exhibited significantly
more canal transportation at D1 than the NiTi groups (p<0.05). CONCLUSION : NiTi
files cause less transportation than KF. At D1 KF were less centered than both NiTi
files. PG remained more centered at Dmc and D7.