title: Effect of Intracanal Cryotherapy on Reducing Root Surface Temperature.
abstract: BACKGROUND
  The positive effect of cryotherapy has been widely described in medicine. The aim of the present study was to validate a new methodology to reduce and maintain external root surface temperature for at least 4 minutes.
  
  
  METHODS
  Twenty extracted single-rooted teeth were instrumented to size 35/.06 and subjected to 2 different irrigation interventions with a repeated-measures design using 5% sodium hypochlorite first (control) and 2.5°C cold saline solution later (experimental). In both, 20 mL of the irrigant solution was delivered for a total time of 5 minutes with a microcannula attached to the EndoVac system (Kerr Endo, Orange County, CA) inserted to the working length. The initial and lowest temperatures were recorded in the apical 4 mm with a digital thermometer for both irrigants. Data were analyzed with the repeated measure analysis of variance (Greenhouse-Geisser correction) and Bonferroni post hoc tests. Differences in maintaining a -10°C temperature reduction over 4 minutes were assessed with the Fisher exact test.
  
  
  RESULTS
  Although significant differences were found between the initial and lowest temperatures in both the control and experimental irrigation procedures (P < .001), the experimental intervention reduced it almost 10 times that of the control. When maintaining a -10°C temperature reduction over 4 minutes, the teeth in the experimental group also sustained significantly better results (P = 3.047 × 10(-10)).
  
  
  CONCLUSIONS
  Using cold saline solution as the final irrigant reduced the external root surface temperature more than 10°C and maintained it for 4 minutes, which may be enough to produce a local anti-inflammatory effect in the periradicular tissues.
authors.affiliation: Department of Postgraduate Endodontics, University of Tlaxcala, Tlaxcala, Mexico; Private Practice, Puebla, Mexico. Electronic address: jveraro@yahoo.com.mx.
authors.forename: Jorge
authors.initials: J
authors.lastname: Vera
authors.affiliation: Department of Postgraduate Endodontics, University of Tlaxcala, Tlaxcala, Mexico; Private Practice, Jalapa, Mexico.
authors.forename: Jorge
authors.initials: J
authors.lastname: Ochoa-Rivera
authors.affiliation: Department of Postgraduate Endodontics, University of Tlaxcala, Tlaxcala, Mexico; Private Practice, Tlaxcala, Mexico.
authors.forename: Marino
authors.initials: M
authors.lastname: Vazquez-Carcaño
authors.affiliation: Private Practice, Puebla, Mexico; Department of Endodontics, Benemerita Universidad Autónoma de Puebla, Puebla, Mexico.
authors.forename: Monica
authors.initials: M
authors.lastname: Romero
authors.affiliation: Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, California.
authors.forename: Ana
authors.initials: A
authors.lastname: Arias
authors.affiliation: Department of Endodontics, University of North Carolina School of Dentistry, Chapel Hill, North Carolina; Lebanese University Dental School, Beirut, Lebanon.
authors.forename: Philippe
authors.initials: P
authors.lastname: Sleiman
mesh_terms: D003080:Cold Temperature; D017679:Cryotherapy / Q000379:methods*; D006801:Humans; D003765:Models, Dental; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D013499:Surface Properties; D062125:Thermometry; D014092:Tooth Root
chemical_list: D012388:Root Canal Irrigants
keywords: Cryotherapy; EndoVac; negative pressure irrigation; temperature reduction