Canal master instrumentation: an in vitro study of separation frequency

Ninety resin blocks were instrumented by three different operators using the Canal Master Instrumentation system. The frequency of file separation among three operators of varying endodontic experience (novice dental student to endodontist) was compared. Twenty-one of 87 (24%) of the instruments were separated. The #50 Canal Master file failed most frequently (5 of 21). Three ledges (3 of 90 samples) were created by the novice operator with the Canal Master rotary instruments which could not be bypassed. Separation rates among the operators ranged from 12 of 27 (novice) to 4 of 30 (endodontist). The results suggest that the Canal Master file may be prone to fracture in vitro and that there may be a "learning curve" to proficient Canal Master use.