Comparison of balanced forces, endosonic, and step-back filing instrumentation techniques: quantification of extruded apical debris.

Randomly assigned groups of 15 single-canal, extracted human teeth were instrumented by one of three techniques: balanced forces, endosonic, or step-back filing. Debris extruded from the apical foramen during instrumentation was collected onto preweighed filters using a suction filtration apparatus. Following desiccation, weight determinations were made on an analytical electrobalance. A one-factor analysis of variance was performed on the debris weight data revealing that the endosonic technique apically extruded significantly more debris than the balanced forces technique (p less than 0.05). Further analysis of the data, excluding debris weights greater than 1 SD from the mean, using a one-factor analysis of variance revealed the balanced forces technique apically extruded significantly less debris than either endosonic or step-back filing techniques (p less than 0.05). No significant difference was demonstrated between endosonic and step-back filing techniques.