title: Comparison of the cleaning efficacy of passive sonic activation and passive ultrasonic activation after hand instrumentation in molar root canals.
abstract: The purpose of this study was to compare the cleaning efficacy of passive ultrasonic activation with that of passive sonic activation after hand instrumentation. Sixty curved molar canals were hand-instrumented to size 35 and divided into three groups. Group 1 received no further treatment. Group 2 received 3 min of passive sonic activation. Group 3 received 3 min of passive ultrasonic activation. The roots were split and photomicrographs (x20) were made of the apical 6 mm of canal. A transparent grid was placed over projected images, and the total number of squares covering the apical 6 mm of canal space and the number of squares containing debris were counted. A debris score was calculated for each specimen by dividing the number of squares with debris by the total number of squares. The mean debris scores were 31.6% for hand instrumentation only, 15.1% for the sonic group, and 16.7% for the ultrasonic group. The debris scores for the sonic and ultrasonic activation groups were significantly lower than that for the hand instrumentation only group (p < 0.01); however, there was no significant difference between the sonic and ultrasonic activation groups. Passive sonics after hand instrumentation produces a cleaner canal than hand instrumentation alone and is comparable with that of passive ultrasonics.
authors.affiliation: Naval Dental School, National Naval Dental Center, Bethesda, MD 20889-5602, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Jensen
authors.forename: T L
authors.initials: TL
authors.lastname: Walker
authors.forename: J W
authors.initials: JW
authors.lastname: Hutter
authors.forename: B K
authors.initials: BK
authors.lastname: Nicoll
mesh_terms: D000704:Analysis of Variance; D003754:Dental High-Speed Equipment; D006801:Humans; D008963:Molar; D010784:Photomicrography; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D013010:Sonication; D018709:Statistics, Nonparametric; D019227:Tooth Apex; D014464:Ultrasonic Therapy