A new root canal instrument and instrumentation technique: a preliminary report.

Cleaning and shaping the root canal system has been and continues to be a challenge for even the most experienced endodontist. Curved, narrow canals, in particular, cause difficulties for the beginner as well as the specialist. A new instrument designed to incorporate new concepts was developed to ameliorate the problems in cleaning and shaping root canal systems. This new instrument has been given the name of SW (Senia and Wildey). The new SW instrument uses controlled right and left rotational forces. This motion was used to clean and shape simulated root canals in plastic blocks and root canals in extracted teeth. Instrumentation appeared to be easier, faster, and more precise than with conventional instruments, especially in curved canals where there was remarkable reduction of canal transportation. A mechanical version of the SW instrument was also developed. It was used to flare the coronal portion of the root canal system.