title: Temperature variation on root surface with three root-end cavity preparation techniques.
abstract: BACKGROUND
  Thermal changes can occur on the external root surface when root-end cavity preparation is performed, which may damage periodontal ligament cells and alveolar bone.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the temperature changes during preparation of the root-end cavities at 1 and 3 mm to the sectioned apical root surfaces when either tungsten carbide round bur, diamond round bur or ultrasonic diamond tip was used.
  
  
  METHODS
  Root-end resection was performed at 90 degrees to the long axis of the root, 3 mm from the apex. Specimens were randomly divided into three groups of 12 teeth each for three different root-end cavity preparation techniques to be used, i.e. tungsten carbide bur, diamond bur and ultrasonic diamond retro tip.Thermocouples were used to measure temperature changes at 1 mm (T1) and 3 mm (T2) to the cutting plane during the preparations.
  
  
  RESULTS
  For T1, the lowest and the highest mean temperature increases of 3.53 degrees C and 4.34 degrees C were recorded for the carbide and diamond burs, respectively. For T2, the lowest and the highest mean temperature increases of 2.62 degrees C and 4.39 degrees C where recorded for the carbide and diamond burs, respectively. The mean temperatures with the ultrasonic tip were 3.68 and 3.04 degrees C at T1 and T2 region, respectively. For root-end preparation, the ultrasonic preparation technique took the shortest preparation time (10.25 sec) and the diamond bur took the longest time (28.17 sec).
  
  
  CONCLUSIONS
  Ultrasonic retro tips and burs caused temperature to rise from 2.62 degrees to 4.39 degrees C, and these rises were within safety levels.
authors.affiliation: Endodontics Department, Faculty of Dentistry, Ondokuz Mayis University, Samsun,Turkey. bodrumlu@omu.edu.tr
authors.forename: Emre
authors.initials: E
authors.lastname: Bodrumlu
authors.affiliation: Periodontology Department, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey.
authors.forename: Ilker
authors.initials: I
authors.lastname: Keskiner
authors.affiliation: Dental Surgery Department, Faculty of Dentistry, Ondokuz Mayis University, Samsun,Turkey.
authors.forename: Mahmut
authors.initials: M
authors.lastname: Sumer
authors.affiliation: Dental Surgery Department, Faculty of Dentistry, Ondokuz Mayis University, Samsun,Turkey.
authors.forename: Nazife T
authors.initials: NT
authors.lastname: Telcioglu
mesh_terms: D001047:Apicoectomy; D003737:Dental Cavity Preparation / Q000295:instrumentation / Q000379:methods*; D018130:Diamond; D006801:Humans; D013696:Temperature; D014414:Tungsten; D014465:Ultrasonics
chemical_list: D018130:Diamond; D014414:Tungsten