title: Effect of ultrasonic vibration on post removal in extracted human premolar teeth.
abstract: The purpose of this study was to determine the effectiveness of ultrasonic vibration in removing Paraposts from extracted teeth. Paraposts were cemented in mandibular premolars to a depth of 9 mm with zinc phosphate cement and the teeth placed in four groups. Group 1 received no vibration. Group 2 received vibration for 4 min, group 3 received vibration for 12 min, and group 4 received vibration for 16 min. Tensile forces were applied to the posts and mean dislodgment forces compared. The mean force (kg) required to dislodge the Parapost in group 1 was 24.92 +/- 1.64 SEM; in group 2, 25.01 +/- 1.80; in group 3, 24.08 +/- 2.29; and in group 4, 12.41 +/- 2.60. There was a significant difference between group 4 and groups 1 to 3 (p = 0.0003). Results of this study indicate that 16 min ultrasonic vibration is an effective method for removing Paraposts from human premolar teeth.
authors.affiliation: Department of Endodontics, University of Iowa College of Dentistry, Iowa City 52242-1001, USA.
authors.forename: W T
authors.initials: WT
authors.lastname: Johnson
authors.forename: J M
authors.initials: JM
authors.lastname: Leary
authors.forename: D B
authors.initials: DB
authors.lastname: Boyer
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D002484:Cementation; D017005:Dental Debonding / Q000295:instrumentation* / Q000379:methods; D003762:Dental Instruments; D003799:Dental Stress Analysis; D005069:Evaluation Studies as Topic; D006801:Humans; D011176:Post and Core Technique / Q000295:instrumentation*; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D014465:Ultrasonics; D014732:Vibration