title: Evaluation of root external temperature during the application of ultrasound in removal of intraradicular posts.
abstract: This study evaluated the temperature rise on external root surfaces by simulating the removal of metallic posts by applying ultrasound, with or without refrigeration and at different times. The crowns of 30 healthy maxillary central incisors were removed and the roots were treated endodontically. The prosthetic spaces were prepared and impressions were taken with self-curing acrylic resin. After casting with a copper-aluminum alloy, the posts were blasted with aluminum oxide and cemented with resin cement. The specimens were randomly assigned to three groups according to the time of ultrasonic vibration (30, 60, or 120 seconds) and were subdivided into two groups, those cooled with and without water refrigeration. A thermocouple connected to a digital thermometer was positioned on the root external surface and the maximum temperature was recorded. Data were submitted to ANOVA and Tukey's test. Analysis of the results revealed statistical difference among groups (p < 0.01). Ultrasound (with and without water spray) increased root temperature significantly, reaching values of more than 50 degrees C. The exception was the group that used 30 seconds of ultrasound with refrigeration; root temperature reached 35.4 degrees C, making it the only tested condition that remained below the critical value (50 degrees C).
authors.affiliation: Ribeirao Preto School of Dentistry, University of Ribeirao Preto, Sao Paulo, Brasil.
authors.forename: Angela Delfina Bittencourt
authors.initials: AD
authors.lastname: Garrido
authors.forename: Tabajara Sabbag
authors.initials: TS
authors.lastname: Fonseca
authors.forename: Yara Teresinha Correa
authors.initials: YT
authors.lastname: Silva-Sousa
authors.forename: Edson
authors.initials: E
authors.lastname: Alfredo
authors.forename: Manoel Damiao
authors.initials: MD
authors.lastname: Sousa-Neto
mesh_terms: D000704:Analysis of Variance; D001831:Body Temperature; D017005:Dental Debonding; D003799:Dental Stress Analysis; D020878:Device Removal / Q000379:methods*; D006358:Hot Temperature; D006801:Humans; D007180:Incisor; D011176:Post and Core Technique; D012034:Refrigeration; D019279:Resin Cements; D014092:Tooth Root / Q000502:physiology*; D014465:Ultrasonics; D014732:Vibration
chemical_list: D019279:Resin Cements