title: Changes in intrapulpal temperature after Er:YAG laser irradiation.
abstract: OBJECTIVE
  This study was performed to investigate the changes in temperature induced by an Er:YAG laser irradiation and to find the means to minimize potential thermal damage due to temperature rise after irradiation.
  
  
  BACKGROUND
  Intrapulpal temperature rise was found to last after irradiation at times, although the addition of appropriate water spray during tooth ablation by Er:YAG laser produced efficient ablation with little thermal damage.
  
  
  METHODS
  To investigate intrapulpal temperature change, each extracted tooth specimen was embedded into a resin block and temperature-measuring probes were placed on the irradiated and the opposite pulpal walls. An Er:YAG laser irradiation was performed at 300 mJ/pulse and 20 Hz, with a water flow rate of 1.6 mL/min for 3 sec. Each lasing was followed by (1) no application of post-irradiation water spray, (2) post-irradiation water spray for 1 sec and (3) for 2 sec.
  
  
  RESULTS
  No significant temperature change was found on the irradiated pulpal wall during Er:YAG laser, while there existed significant temperature rise on the irradiated pulpal wall after irradiation. However, the addition of water spray for 1 or 2 sec after irradiation significantly decreased intrapulpal temperature compared to no application of post-irradiation water spray. There were no significant differences between the 1- and 2-sec groups.
  
  
  CONCLUSIONS
  It is suggested that the addition of water spray for 1 or more seconds after irradiation reduces post-irradiation temperature rise, possibly leading to thermal damage on the dental pulp tissue.
authors.affiliation: Department of Oral Medicine, Dankook University School of Dentistry, Cheonan, Korea.
authors.forename: N S
authors.initials: NS
authors.lastname: Park
authors.forename: K S
authors.initials: KS
authors.lastname: Kim
authors.forename: M E
authors.initials: ME
authors.lastname: Kim
authors.forename: Y S
authors.initials: YS
authors.lastname: Kim
authors.forename: S W
authors.initials: SW
authors.lastname: Ahn
mesh_terms: D001831:Body Temperature / Q000528:radiation effects*; D003782:Dental Pulp / Q000502:physiology / Q000528:radiation effects*; D006801:Humans; D053685:Laser Therapy; D014867:Water
chemical_list: D014867:Water