title: Comparison of different ultrasonic vibration modes for post removal.
abstract: This in vitro study compared different ultrasonic vibration modes for intraradicular cast post removal. The crowns of 24 maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the canals were treated endodontically. The post holes were prepared and root canal impressions were taken with self-cured resin acrylic. After casting, the posts were cemented with zinc phosphate cement. The samples were randomly distributed into 3 groups (n=8): G1: no ultrasonic vibration (control); G2: tip of the ultrasonic device positioned perpendicularly to core surface and close to the incisal edge; and G3: tip of the ultrasonic device positioned perpendicularly to core surface at cervical region, close to the line of cementation. An Enac OE-5 ultrasound unit with an ST-09 tip was used. All samples were submitted to the tensile test using an universal testing machine at a crosshead speed of 1 mm/min. Data were subjected to one-way ANOVA and Tukey's post-hoc tests (α=0.05). Mean values of the load to dislodge the posts (MPa) were: G1 = 4.6 (± 1.4) A; G2 = 2.8 (± 0.9) B, and G3= 0.9 (± 0.3) C. Therefore, the ultrasonic vibration applied with the tip of device close to the core's cervical area showed higher ability to reduce the retention of cast post to root canal.
authors.affiliation: Department of Dentistry, State University of Montes Claros, MG, Brazil.
authors.forename: Neilor Mateus Antunes
authors.initials: NM
authors.lastname: Braga
authors.forename: Juliana Monteiro da
authors.initials: JM
authors.lastname: Silva
authors.forename: Jacy Ribeiro de
authors.initials: JR
authors.lastname: Carvalho-Júnior
authors.forename: Raquel Conceição
authors.initials: RC
authors.lastname: Ferreira
authors.forename: Paulo César
authors.initials: PC
authors.lastname: Saquy
authors.forename: Manoel
authors.initials: M
authors.lastname: Brito-Júnior
mesh_terms: D000704:Analysis of Variance; D002484:Cementation; D003481:Cuspid / Q000601:surgery; D017005:Dental Debonding / Q000295:instrumentation*; D003799:Dental Stress Analysis / Q000379:methods; D006801:Humans; D066298:In Vitro Techniques; D011176:Post and Core Technique / Q000295:instrumentation*; D012390:Root Canal Therapy / Q000379:methods; D014465:Ultrasonics / Q000295:instrumentation*; D014732:Vibration; D015036:Zinc Phosphate Cement / Q000737:chemistry*
chemical_list: D015036:Zinc Phosphate Cement