title: Heat production by 3 implant drill systems after repeated drilling and sterilization.
abstract: OBJECTIVE
  The goal was to measure heat generated in bone by 3 implant drill systems after repeated drilling and sterilization.
  
  
  METHODS
  Temperature was measured with thermocouple technology in vitro using the bovine femoral cortical bone model. Intermittent drilling was accomplished at a constant 2.4-kg load and drill speed of 2,500 rpm. External irrigation at 40 mL/min with normal saline was used. Three implant drill systems-system A (triple twist drills with a relief angle), system B (triple twist drills without a relief angle), and system C (double twist drills with a relief angle)-were evaluated and heat was measured at the final drill in the drilling sequence (4.0 mm or 4.2 mm) at a depth of 15 mm. Thermocouples were placed 0.5 mm from the osteotomy at a depth of 15 mm. Heat measurements were recorded out to 25 uses.
  
  
  RESULTS
  Results showed temperature increased with multiple uses. System A and C drills had temperature measurements that were below 47 degrees C, even after 25 uses. System B drills had temperatures that exceeded 47 degrees C from the initial use. Light microscopy showed little drill wear even after 25 uses.
  
  
  CONCLUSIONS
  Drill geometry plays a major role in heat production and may explain the increased temperature readings seen in system B. These drills lack relief angles and have the smallest clearance angles of the 3 systems. It also has fewer drills in its drilling sequence compared with systems A and C. This study shows that temperatures increase when drills are used multiple times. Systems A and C had acceptable temperature measurements out to 25 uses. System B drills showed significantly higher heat production with little visual signs of wear.
authors.affiliation: Department of Oral and Maxillofacial Surgery, College of Dentistry, The Ohio State University, Columbus, OH 43218-2357, USA. chacon.4@osu.edu
authors.forename: Guillermo E
authors.initials: GE
authors.lastname: Chacon
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Bower
authors.forename: Peter E
authors.initials: PE
authors.lastname: Larsen
authors.forename: Edwin A
authors.initials: EA
authors.lastname: McGlumphy
authors.forename: F Michael
authors.initials: FM
authors.lastname: Beck
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000601:surgery; D002417:Cattle; D003758:Dental Implantation, Endosseous / Q000009:adverse effects / Q000295:instrumentation; D003762:Dental Instruments / Q000009:adverse effects*; D004867:Equipment Design / Q000009:adverse effects; D005269:Femur / Q000601:surgery; D006358:Hot Temperature; D010027:Osteotomy / Q000295:instrumentation*