AIM : To compare (i) canal‐centring ability and transportation of K‐files, ProGlider and One‐G files after glide path preparation in curved root canals; (ii) changes in canal volume after glide path preparation, using micro‐computed tomography.
METHODOLOGY : A total of 135 mesiobuccal root canals of maxillary molars were randomly divided into three glide path groups: (i) pre‐curved sizes 10‐15‐20 K‐files (n = 45); (ii) size 10 K‐file followed by One‐G (n = 45); and (iii) size 10 K‐file followed by ProGlider (n = 45). Micro‐CT was used to scan teeth before and after glide path preparation; the isotropic voxel size of the micro‐CT scans was 22 μm. Centring ratio values and canal transportation values were compared between the three glide path preparation groups at the apical, midroot and coronal levels. Changes in canal volume were compared for all glide path groups. The results were analysed statistically using a one‐way anova and Kruskal–Wallis H tests.
RESULTS : One‐G and ProGlider displayed significantly greater mean centring ratio values than K‐files at all levels examined (P < 0.05). Apical canal transportation values after glide path preparation were significantly higher for the K‐files (P < 0.05). At the midroot and coronal levels, canal transportation results were statistically similar for all glide path groups (P > 0.05). Changes in canal volume were statistically similar for the three glide path groups (P > 0.05).
CONCLUSION : One‐G and ProGlider were significantly more centred at the apical, midroot and coronal levels than K‐files. Apical canal transportation ratio values after glide path enlargement were significantly higher for K‐files than for One‐G and ProGlider. All groups resulted in similar canal volume changes.