Introduction: The aim of this study was to evaluate apical transportation and working length changes after instrumentation using EndoSequence (Brasseler USA, Savannah, GA) and Guidance V-taper (Guidance Endo, Albuquerque, NM) rotary files.
Methods: Forty-four mesiobuccal and mesiolingual canals of extracted mandibular first and second molars were instrumented by using EndoSequence or Guidance NiTi rotary files. Group 1 (n = 22) was instrumented with EndoSequence #30/.06, #25/.06, and #20/.06 files in a crown-down technique until apical enlargement with #25/.06 was achieved at the working length. Group 2 (n = 22) was instrumented with Guidance #30/.10, #25/.08, and #20/.06 files in a crown-down method until apical enlargement with #25/.08 was reached. A double digital radiographic technique was used to measure the loss of working length and canal transportation at 0, 1, and 3 mm from the working length. Measurements were analyzed by using repeated-measures analysis of variance.
Results: The average amount of transportation at 0, 1, and 3 mm was 0.077 mm, 0.039 mm, and 0.040 mm for the EndoSequence group and 0.066 mm, 0.046 mm, and 0.05 mm for the Guidance group, respectively. The loss of working length was 0.001 mm for the EndoSequence group and -0.002 mm for the Guidance group.
Conclusion: There was no statistically significant difference in the loss of working length or transportation at the measured level between EndoSequence and Guidance rotary files.