Intrapulpal Temperature Increases Caused by 445-nm Diode Laser-Assisted Debonding of Self-Ligating Ceramic Brackets During Simulated Pulpal Fluid Circulation

Photomed Laser Surg. 2018 Apr;36(4):185-190. doi: 10.1089/pho.2017.4356. Epub 2018 Jan 3.

Abstract

Objective: This study investigated temperature increases in dental pulp resulting from laser-assisted debonding of ceramic brackets using a 445-nm diode laser.

Materials and methods: Eighteen ceramic brackets were bonded in standardized manner to 18 caries-free human third molars. Pulpal fluid circulation was simulated by pumping distilled water at 37°C through the pulp chamber. The brackets were irradiated with a 445-nm diode laser. Temperatures were measured using a thermal camera at points P1 (center of the pulp) and P2 (in the hard dental tissue) at the baseline (T0), at the start and end of laser application (T1 and T2), and the maximum during the sequence (Tmax).

Results: Significant differences in the temperatures measured at P1 and P2 were observed among T0, T1, T2, and Tmax. Significant increases in temperature were noted at points P1 and P2, between T1 and T2, T1 and Tmax, and T2 and Tmax. The maximum P2 values were significantly higher than at P1. The maximum temperature increase measured in the pulp was 2.23°C, lower than the critical threshold of 5.5°C.

Conclusions: On the basis of the laser settings used, there is no risk to the vitality of dental pulp during laser-assisted debonding of ceramic brackets with a 445-nm diode laser.

Keywords: 445nm diode laser; bracket debonding; pulpal temperature; simulated pulp circulation; thermal camera.

MeSH terms

  • Body Temperature*
  • Ceramics
  • Dental Debonding*
  • Dental Pulp / radiation effects*
  • Humans
  • Lasers, Semiconductor / therapeutic use*
  • Low-Level Light Therapy*
  • Molar / radiation effects
  • Orthodontic Brackets*
  • Tissue Culture Techniques