Purpose: Bleaching procedures photoactivated by blue LED devices are commonly used. Since there are no scientific reports about pulp chamber temperature changes during blue LED use for bleaching agent activation, the purpose of this study is to quantify the intrapulpal temperature changes following irradiation at the enamel surface with a new blue LED system. Materials and Methods: Nine extracted permanent teeth (3 central maxillary incisors, 3 central mandibular incisors, 3 canines) were used. A high-precision thermocouple was inserted into the pulp chamber with a thermal conducting paste, and temperature changes were plotted. Results: The temperature increased by as much as 9°C, which would probably cause permanent pulpal damage. Conclusion: With the data obtained, it is possible to program the bleaching procedure accordingly to avoid thermal sensitivity and damage.

Keywords: LED, bleaching agent, human enamel, temperature response, photo activation