title: An in vivo comparison of the step-back technique versus a step-back/ultrasonic technique in human mandibular molars.
abstract: This study compared the in vivo debridement efficacy of the step-back preparation versus a step-back/ultrasound preparation in the mesial root canals of vital human mandibular molars. Group 1 consisted of 15 teeth prepared with a step-back technique using intermittent irrigation with 5.25% sodium hypochlorite. Group 2 consisted of 23 teeth prepared with a step-back technique as in group 1 followed by 3 min of ultrasonic instrumentation (Cavi-Endo) using 5.25% sodium hypochlorite (30 ml per min). Group 3 consisted of 21 teeth which were uninstrumented and served as controls. Following extraction and histological preparation, the 1- and 3-mm levels of the canal and isthmus were evaluated for percentage of tissue removal using a compensating polar planimeter. At the 3-mm level, there were no statistical differences in canal or isthmus cleanliness between the step-back group and the step-back/ultrasound group. At the 1-mm apical level, statistical analysis indicated that the step-back/ultrasonic technique was superior to the step-back technique in canal (99.6% versus 88%) and isthmus (86% versus 10%) cleanliness.
authors.forename: J
authors.initials: J
authors.lastname: Haidet
authors.forename: A
authors.initials: A
authors.lastname: Reader
authors.forename: M
authors.initials: M
authors.lastname: Beck
authors.forename: W
authors.initials: W
authors.lastname: Meyers
mesh_terms: D000328:Adult; D006801:Humans; D008334:Mandible; D008963:Molar; D012390:Root Canal Therapy / Q000379:methods*; D014464:Ultrasonic Therapy / Q000379:methods