title: In Vivo Intracanal Temperature Evolution during Endodontic Treatment after the Injection of Room Temperature or Preheated Sodium Hypochlorite.
abstract: BACKGROUND
  Heating a sodium hypochlorite solution improves its effectiveness. The aim of this study was to measure the in vivo temperature changes of sodium hypochlorite solutions that were initially preheated to 66°C or at room temperature inside root canals during routine irrigation.
  
  
  METHODS
  Thirty-five root canals were prepared to ISO size 40 with 4% taper. A type K (nickel-chromium-nickel) thermocouple microprobe (Testo NV, Ternat, Belgium) was positioned within 3 mm of the working length to measure the temperature at 1-second intervals. In each canal, 2 test protocols were evaluated in a randomized order with 3% sodium hypochlorite solutions: (1) preheated to 66°C and (2) at room temperature. The temperature measurements began 5 seconds before the 25 seconds of irrigant injections and continued for 240 seconds. This resulted in 270 data points for each protocol.
  
  
  RESULTS
  The temperature of the irrigant at room temperature increased from the initial intracanal temperature after injection of 20.7°C (±1.2°C) to 30.9°C (±1.3°C) in 10 seconds and to 35°C (±0.9°C) after 240 seconds. The temperature of the preheated to 66°C solution decreased from 56.4°C (±2.7°C) to 45.4°C (±3.0°C) after 5 seconds, reached 37°C (±0.9°C) after 60 seconds, and reached 35.7°C (±0.8°C) after 240 seconds.
  
  
  CONCLUSIONS
  The original temperatures of the sodium hypochlorite solutions were buffered inside the root canal and tended to rapidly evolve to equilibrium. The findings of this study contribute to an improved understanding of the thermodynamic behaviors of irrigant solutions inside root canals in vivo.
authors: Department of Oral Health Sciences, Free University of Brussels (VUB), Brussels, Belgium. Electronic address: ferdehemptinne@yahoo.fr.
authors: Ferdinand
authors: F
authors: de Hemptinne
authors: Department of Oral Health Sciences, Free University of Brussels (VUB), Brussels, Belgium.
authors: Gunter
authors: G
authors: Slaus
authors: Department of Oral Health Sciences, Free University of Brussels (VUB), Brussels, Belgium.
authors: Mathieu
authors: M
authors: Vandendael
authors: Department of Oral Health Sciences, Free University of Brussels (VUB), Brussels, Belgium; Department of Educational Sciences EDWE, Free University of Brussels (VUB), Brussels, Belgium.
authors: Wolfgang
authors: W
authors: Jacquet
authors: Department of Restorative Dentistry and Endodontology, Dental School, Ghent University, Ghent University Hospital, Gent, Belgium.
authors: Roeland J
authors: RJ
authors: De Moor
authors: Department of Oral Health Sciences, Free University of Brussels (VUB), Brussels, Belgium.
authors: Peter
authors: P
authors: Bottenberg
mesh_terms: D003786:Dental Pulp Cavity / Q000502:physiology*; D004202:Disinfectants / Q000008:administration & dosage*; D006801:Humans; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D018915:Root Canal Preparation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000008:administration & dosage*; D013696:Temperature
chemical_list: D004202:Disinfectants; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite
keywords: In vivo; intracanal temperature; irrigation; sodium hypochlorite