title: Temperature evolution of preheated irrigant injected into a root canal ex vivo.
abstract: OBJECTIVE
  The aim of this study is to test the influence of the temperature of the surrounding medium, flow rate, duration of irrigation, and apical patency on the evolution of the temperature of irrigants injected in a root canal.
  
  
  METHODS
  Thermocouples were inserted into an incisor at different positions to monitor irrigant temperature during and after injection at 21, 45, or 60 °C. The tooth was immersed in a water bath at 21 and 37 °C.
  
  
  RESULTS
  Preheated syringes were used for up to 2.5 min before being cooled down from 60 to below 45 °C. The irrigant temperature was higher apically than at coronal levels (P ≤ 0.028). The duration of irrigation had no influence on the average temperatures during delivery (P ≥ 0.337), but the apical patency lowered the intracanal temperature (P = 0.004). The highest temperature measured on the outside of the tooth was 39 °C.
  
  
  CONCLUSIONS
  Preheating the irrigant at 60 °C resulted in temperatures higher than 45 °C throughout the root canal, during irrigant delivery. After completion, the temperature dropped rapidly.
  
  
  CONCLUSIONS
  These results contribute to a better understanding of the optimum irrigant delivery time at given temperature, the cooling rate of irrigant in the syringe, and the influence of heated irrigant temperature in the periodontium, which should guide the preheated syringe turnover.
authors.affiliation: Centre for Dentistry and Oral Hygiene, University Medical Centre Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands. rgdmacedo@gmail.com.
authors.forename: Ricardo G
authors.initials: RG
authors.lastname: Macedo
authors.affiliation: Physics of Fluids Group, Faculty of Science and Technology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
authors.forename: Bram
authors.initials: B
authors.lastname: Verhaagen
authors.affiliation: Physics of Fluids Group, Faculty of Science and Technology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
authors.forename: Michel
authors.initials: M
authors.lastname: Versluis
authors.affiliation: Centre for Dentistry and Oral Hygiene, University Medical Centre Groningen, University of Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
authors.forename: Luc
authors.initials: L
authors.lastname: van der Sluis
mesh_terms: D006801:Humans; D066298:In Vitro Techniques; D007180:Incisor; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D013594:Syringes; D013696:Temperature; D007507:Therapeutic Irrigation / Q000379:methods*
chemical_list: D012388:Root Canal Irrigants
keywords: Heat; Root canal irrigant; Sodium hypochlorite; Temperature