Temperature rises during tooth bleaching with different light-curing units

Ozyilmaz O. Y., Yavuz T., Sari T., Aykent F., Ozturk A. N.

Journal of Adhesion Science and Technology, vol.29, no.15, pp.1572-1580, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 29 Issue: 15
  • Publication Date: 2015
  • Doi Number: 10.1080/01694243.2015.1035490
  • Journal Name: Journal of Adhesion Science and Technology
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1572-1580
  • Keywords: light-curing units, laser, thermocouple, bleaching, pulpal health
  • Istanbul Medipol University Affiliated: Yes


The aim of this study was to evaluate the influence of three different light-curing units on the temperature rise induced in the pulpal cavity, when bleached with 35% hydrogen peroxide (HP). Forty extracted maxillary central incisors were randomly divided into four groups according to photoactivation procedure (n = 10). Whiteness HP (WHP) bleaching agent which contains 35% HP bleach was placed on the facial tooth surface and no photoactivation device was used (control); an blue light-emitting diode (LED, 40 s), a diode laser (4 W, Continous mode, 20 s), and Nd:YAG laser (4 W, 60 Hz frequency, 20 s). Temperature rise in the pulpal chamber was measured with a J-type thermocouple wire that was connected to a data logger before and immediately after each 20-40 s application. One tooth of each group was selected for scanning electron microscope analysis. Data were analyzed using one-way ANOVA followed by the Games Howell post hoc test at a preset of 0.05. One-way ANOVA revealed that there was a significant difference among the light-curing units (p < 0.05) and between control group and light-curing units (p < 0.05). The Nd:YAG induced significantly, which resulted in higher temperature increase than other light-curing units (10.7 °C). The LED unit produced the lowest temperature changes (3.2 °C) among the light-curing units. The presence of the bleaching gel did not cause a temperature increase in control group (0 °C). The results suggested that using light-curing units caused temperature changes in the intrapulpal cavity during tooth bleaching. The use of LED will be more safer for pulpal health when assisted with WHP bleaching gel.