title: Temperature rise of the post and on the root surface during ultrasonic post removal.
abstract: OBJECTIVE
  To determine the temperature rise on the root surface caused by ultrasonic post removal using different devices and techniques in a laboratory setting.
  
  
  METHODS
  Two ultrasonic devices, one piezoelectrical (Pi) and one magnetostrictive (Ma), were investigated. A serrated titanium post was placed into the distal root canal of a human mandibular first molar. Four coolant parameters were utilized: no air, no water, no evacuation (NN), air only with high-speed evacuation (A), 15 mL min(-1) water coolant with high-speed evacuation (W15) and 30 mL min(-1) water coolant with high-speed evacuation (W30). Five simulated post removals were measured at two locations, the post (P) and the root (R), for each coolant parameter. Temperature rise was measured at 30, 60, 90 and 120 s intervals using calibrated infrared thermography (n = 80). Temperatures were recorded at 45 ms intervals. Data were analysed using repeated measures anova with the Scheffe post hoc test (P < or = 0.05).
  
  
  RESULTS
  The overall mean pooled effect showed that temperature rise for P = 20.1 +/- 27.9 degrees C and R = 10.9 +/- 7.9 degrees C were significantly different. Significant differences in temperature rise were: Pi > Ma, P > R, NN > A = W15 = W30 however, A > W30.
  
  
  CONCLUSIONS
  There were significant differences in temperature rise as a function of ultrasonic device, location on the tooth and cooling method utilized for post removal.
authors.affiliation: Department of Preventive and Restorative Dental Sciences, School of Dentistry, University of California, San Francisco, CA, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Budd
authors.forename: D
authors.initials: D
authors.lastname: Gekelman
authors.forename: J M
authors.initials: JM
authors.lastname: White
mesh_terms: D000388:Air; D000704:Analysis of Variance; D001831:Body Temperature; D020878:Device Removal / Q000295:instrumentation*; D006358:Hot Temperature; D006801:Humans; D008963:Molar; D011176:Post and Core Technique; D014092:Tooth Root / Q000502:physiology*; D014159:Transducers; D014465:Ultrasonics / Q000009:adverse effects*; D014867:Water
chemical_list: D014867:Water