Comparison of two endodontic handpieces during the preparation of root canals in extracted human teeth

Abstract

This in vitro study compared and assessed two endodontic handpieces during the preparation of root canals in extracted human teeth. Eighty extracted human teeth, with single root canals, were divided into eight matched groups. They were prepared using Shaper files activated by the MM1500 Sonic Air handpiece (Micro-Mega, Besançon, France) or Excalibur files activated by the W & H Excalibur 969 handpiece (W & H, Bürmoos, Austria). The files were 21 mm or 25 mm in length. When preparing the canals, the files were used either in line with or perpendicular to any canal curvature. Preparation of the canals was carried out using the techniques described in the manufacturers' literature. A variety of parameters were used to compare the handpieces, including canal preparation time, deformation or fracture of instruments, loss of canal length, weight loss from the prepared teeth and the overall postpreparation canal shape. A microradiographic technique was used to produce a tracing record of the pre- and postpreparation canal shape. Both handpieces provided an efficient and easy method of preparing and shaping the root canal with little operator fatigue. The MM1500 Sonic air handpiece took significantly more time (P < 0.001) to prepare the canals than the Excalibur. Few aberrations in the shapes of prepared canals were created by either handpiece. No endodontic file fractured but a few of them were permanently deformed. The effects of two variables--file length and the plane of use of the file--on performance of the handpieces, were also assessed.