The purpose of the present study is to evaluate
smear layer generation and residual debris after using self-adjusting file (
SAF) or rotary instrumentation and to compare the debris and
smear layer removal efficacy of the
SAF cleaning/shaping irrigation system against final agitation techniques. One hundred and eight maxillary lateral incisor teeth were randomly divided into nine experimental groups (n = 12), and root canals were prepared using ProTaper Universal rotary files, with the exception of the
SAF instrumentation group. During instrumentation, root canals were irrigated with a total of 16 mL of 5% NaOCl. For final irrigation, rotary-instrumented groups were irrigated with 10 mL of 17%
EDTA and 10 mL of 5% NaOCl using different irrigation agitation regimens (syringe irrigation with needles, NaviTip FX, manual dynamic irrigation, CanalBrush, EndoActivator, EndoVac, passive ultrasonic irrigation (PUI), and
SAF irrigation). In the
SAF instrumentation group, root canals were instrumented for 4 min at a rate of 4 mL/min with 5% NaOCl and received a final flush with same as syringe irrigation with needles. The surface of the root dentin was observed using a scanning electron microscope. The
SAF instrumentation group generated less
smear layer and yielded cleaner canals compared to rotary instrumentation. The EndoActivator, EndoVac, PUI, and
SAF irrigation groups increased the efficacy of irrigating solutions on the
smear layer and debris removal. The
SAF instrumentation yielded cleaner canal walls when compared to rotary instrumentation. None of the techniques completely removed the
smear layer from the root canal walls.