Micro-computed tomographic evaluation of the shaping characteristics of different root canal preparation techniques in primary and permanent teeth

This micro-computed tomography (μCT) study was conducted to evaluate the changes in root canal morphology following root canal preparation with rotary and conventional file systems in primary and permanent teeth. Extracted primary and permanent molars (both n=36) were selected and randomly assigned to 6 subgroups (n=12/group) with regard to the file system tested. Following prescanning of teeth, the root canals were prepared using a multi-file rotary system, a single-file rotary system and conventional endodontic files. Thereafter, the teeth were rescanned by (μCT) with the preoperative alignment and parameters fixed. The data obtained from baseline and post-instumentation scans were superimposed using mage analysis toolkit, and the morphological changes were calculated. Statistical analysis of the data was made using Mann-Whitney U Test, Kruskal-Wallis Test and Conover's Multiple Comparison Test. In both primary and permanent teeth, the differences in volume and surface area was significantly higher after rotary instrumentation compared to conventional shaping (p<0,001). The percentage of untouched surface area was significantly lower in both rotary file groups (p=0,009 ve p<0,001). Permanent teeth had significantly less untouched surface area than primary teeth (p<0,001). Apical transportation in both mesiodistal and buccolingual directions were significantly greater in permanent teeth (p=0,002 ve p<0,001).