title: Instrumentation of root canals in molar using the step-down technique.
mesh_terms: D006801:Humans; D008963:Molar / Q000033:anatomy & histology*; D011670:Pulpectomy / Q000379:methods; D012390:Root Canal Therapy / Q000295:instrumentation / Q000379:methods*; D014092:Tooth Root / Q000033:anatomy & histology