An in vitro study on taper of single root canal of mandibular second premolars of 13-23 year-old people / 华西口腔医学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To determine the root canal initial taper of mandibular second premolars of 13-23 year-old people by using Micro-CT.</p><p><b>METHODS</b>23 extracted, single root, human root canal of mandibular second premolars of 13-23 year-old people were selected. The teeth were embedded in resin. The resins were scanned using Micro-CT at a resolution of 10 microm. The photographs at each level of 1 mm perpendicular to the long axis of the tooth were chosen. Bucco-lingual (BL) and mesio-distal (MD) diameters of each canal were measured at cervical, middle and apical third of the canals. Finally the taper were calculated and analyzed.</p><p><b>RESULTS</b>The average taper of cervical, middle, and apical third of adolescents' root canals were 0.06, 0.08, 0.07 (mesio-distal direction) and 0.32, 0.21, 0.25 (bucco-lingual direction). The difference was not observed among thee level on mesiodistal direction about the canal taper by t-test (P > 0.05), but there was difference among three level on bucco-lingual direction about the canal taper by t-test (P < 0.05).</p><p><b>CONCLUSION</b>The change of bucco-lingual taper of mandibular second premolar of 13-23 year-old people is obvious, and the smallest taper is in middle third of the canal. The mesio-distal taper of the canals is smaller than the bucco-lingual taper and the change of mesio-distal taper isn't obvious.</p>