title: Temperature rise during experimental light-activated bleaching.
abstract: The purpose of this study was to evaluate the surface and intrapulpal temperatures after treatments with different bleaching gels subjected to different types of light activation. A K-type thermocouple and infrared thermometer were used to measure the temperature increase during the 15- or 30-min treatment period. Light-emitting diode with a center wavelength of 405 nm (LED405), organic light-emitting diode (OLED), and femtosecond laser were tested and compared to ZOOM2. The tooth surface was treated with five bleaching agents and Vaseline which served as a control.The generalized estimating equation (GEE) model was applied for testing the differences in temperature increase. The ZOOM2 light source led to the largest increase in mean pulpal and tooth surface temperatures of 21.1 and 22.8 °C, followed by focused femtosecond laser which increased the pulpal and surface temperatures by up to 15.7 and 16.8 °C. Treatments with unfocused femtosecond laser, LED405, and OLED induced significantly lower mean temperature increases (p < 0.001 for each comparison with ZOOM2 and focused femtosecond laser), both in the pulp chamber (up to 2.7, 2.5, and 1.4 °C) and at the tooth surface (up to 3.2, 3.4, and 1.8 °C). Significant differences between pulp chamber and tooth surface measurements were obtained for all types of bleaching gel, during treatments with ZOOM2 (p < 0.001), LED405 (p < 0.001), and unfocused (p < 0.001) and focused femtosecond laser (p ≤ 0.002). Different bleaching agents or Vaseline can serve as an isolating layer. Focused femtosecond laser and ZOOM2 produced large temperature increases in the pulp chamber and at the tooth surface. Caution is advised when using these types of light activation, while LED405, OLED, and unfocused femtosecond laser could be safely used.
authors.affiliation: Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Gunduliceva 5, 10000, Zagreb, Croatia, eklaric@sfzg.hr.
authors.forename: Eva
authors.initials: E
authors.lastname: Klaric
authors.forename: Mario
authors.initials: M
authors.lastname: Rakic
authors.forename: Ivan
authors.initials: I
authors.lastname: Sever
authors.forename: Zrinka
authors.initials: Z
authors.lastname: Tarle
mesh_terms: D001831:Body Temperature; D003782:Dental Pulp; D003786:Dental Pulp Cavity / Q000528:radiation effects; D006801:Humans; D007180:Incisor / Q000528:radiation effects*; D007259:Infrared Rays; D053685:Laser Therapy / Q000379:methods*; D007834:Lasers; D016877:Oxidants; D013696:Temperature; D013821:Thermometers; D013997:Time Factors; D014073:Tooth Bleaching / Q000295:instrumentation* / Q000379:methods
chemical_list: D016877:Oxidants