ABSTRACT Aim: This study aimed to evaluate the safety and efficiency of rotary instrumentation as the first file to length (FFL) in establishing patency using the Woodpecker Ai handpiece with an integrated electronic apex locator (EAL). Methods: Mesial canals of extracted mandibular molars ( n = 56) were randomly assigned to two groups. In the control group (CTL, n = 25), working length was determined with a #10 K-file prior to instrumentation with 15/0.03 miniKUT rotary files using the Woodpecker Ai handpiece. In the experimental group (FFL, n = 31), canals were instrumented directly with the 15/0.03 miniKUT rotary files without preliminary scouting or working length determination. Incidence of file separation and time to achieve patency were recorded. Statistical analysis compared the time between groups and assessed the correlation between canal lengths determined by the Root ZX II (gold standard) and the Woodpecker Ai EAL. Results: Patency was achieved in all canals. Median times to achieve patency were 55.22 s (CTL) and 24.24 s (FFL). No file separations occurred in either group. Lengths determined by the Root ZX II and Woodpecker AI EAL showed strong correlation (98% at 0.5 and 98.4% at 0.0 points). Conclusions: Rotary instrumentation, as the FFL, significantly reduced patency time compared to traditional hand file working length determination before rotary use. This technique appears safe in selective cases but requires further research to confirm its safety and efficacy in more complex scenarios.
Daigle et al. (Fri,) studied this question.