title: Temperature rise caused in the pulp chamber under simulated intrapulpal microcirculation with different light-curing modes.
abstract: OBJECTIVE
  To evaluate and compare intrapulpal temperature rise with three different light-curing units by using a study model simulating pulpal blood microcirculation.
  
  
  METHODS
  The roots of 10 extracted intact maxillary central incisors were separated approximately 2 mm below the cement-enamel junction. The crowns of these teeth were fixed on an apparatus for the simulation of blood microcirculation in pulp. A J-type thermocouple wire was inserted into the pulp chamber through a drilled access on the palatal surfaces of the teeth. Four measurements were made using each tooth for four different modes: group 1, 1000 mW/cm(2) for 15 seconds; group 2, 1200 mW/cm(2) for 10 seconds; group 3, 1400 mW/cm(2) for 8 seconds; and group 4, 3200 mW/cm(2) for 3 seconds. The tip of the light source was positioned at 2 mm to the incisor's labial surface.
  
  
  RESULTS
  The highest temperature rise was recorded in group 1 (2.6°C ± 0.54°C), followed by group 2 (2.57°C ± 0.62°C) and group 3 (2.35°C ± 0.61°C). The lowest temperature rise value was found in group 4 (1.74°C ± 0.52°C); this value represented significantly lower ΔT values when compared to group 1 and group 2 (P  =  .01 and P  =  .013, respectively).
  
  
  CONCLUSIONS
  The lowest intrapulpal temperature rise was induced by 3200 mW/cm(2) for 3 seconds of irradiation. Despite the significant differences among the groups, the temperature increases recorded for all groups were below the critical value of 5.6°C.
authors.affiliation: a  Associate Professor and Department Chair, Department of Orthodontics, Faculty of Dentistry, Bezmialem Vakif University, Istanbul, Turkey.
authors.forename: Sabri Ilhan
authors.initials: SI
authors.lastname: Ramoglu
authors.forename: Hilal
authors.initials: H
authors.lastname: Karamehmetoglu
authors.forename: Tugrul
authors.initials: T
authors.lastname: Sari
authors.forename: Serdar
authors.initials: S
authors.lastname: Usumez
mesh_terms: D001831:Body Temperature / Q000502:physiology* / Q000528:radiation effects; D055117:Curing Lights, Dental / Q000145:classification; D003782:Dental Pulp / Q000098:blood supply* / Q000528:radiation effects; D003786:Dental Pulp Cavity / Q000502:physiology* / Q000528:radiation effects; D006801:Humans; D055115:Light-Curing of Dental Adhesives / Q000295:instrumentation / Q000379:methods*; D008422:Materials Testing; D008833:Microcirculation / Q000502:physiology / Q000528:radiation effects; D013821:Thermometers; D013997:Time Factors
keywords: Bonding; Light-curing units; Microcirculation; Temperature rise