In vitro study of the pulp chamber temperature rise during light-activated bleaching

Area of Science:

• Dentistry
• Biomaterials Science
• Dental Therapeutics

Background:

• Light-activated dental bleaching is a common cosmetic procedure.
• Pulp chamber temperature rise during bleaching is a concern for pulpal health.
• Different light sources may induce varying thermal effects.

Purpose of the Study:

• To evaluate in vitro the pulp chamber temperature rise induced by different light sources used in dental bleaching.
• To compare the thermal effects of halogen light, LED unit, and LED-laser systems.
• To assess if the presence of a bleaching agent influences temperature rise.

Main Methods:

• Extracted human mandibular incisors were prepared with sensors in the pulp chamber.
• Teeth were subjected to 35% hydrogen peroxide gel or no gel.
• Three light sources (halogen, LED, LED-laser) were applied for 30 seconds at 5 mm distance.
• Temperature changes were recorded and analyzed using the Kruskal-Wallis test.

Main Results:

• Halogen light induced significantly higher temperature rises compared to LED and LED-laser systems, both with and without bleaching agent.
• LED and LED-laser systems showed comparable and significantly lower temperature increases.
• The highest temperature rise was observed with halogen light without bleaching agent (2.38°C), and the lowest with LED-laser system with bleaching agent (0.33°C).

Conclusions:

• Halogen light sources generate greater pulp chamber temperature increases during light-activated dental bleaching than LED and LED-laser systems.
• The tested light-curing units resulted in temperature increases within safe limits for pulpal health.
• LED and LED-laser systems are preferable for minimizing thermal stress on the pulp during bleaching procedures.