title: An in vitro comparison of the step-back technique versus a step-back/ultrasonic technique for 1 and 3 minutes.
mesh_terms: D003786:Dental Pulp Cavity / Q000648:ultrastructure; D003804:Dentin / Q000648:ultrastructure; D006801:Humans; D008963:Molar; D012390:Root Canal Therapy / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors; D014464:Ultrasonic Therapy / Q000295:instrumentation / Q000379:methods*