Thermal Effects of 445 nm Laser Irradiation on the Bovine Tongue Tissues Ex Vivo

Abstract

The purpose of this study was to employ the use of thermographic techniques to compare temperature changes and thermal heat transfer patterns in soft tissues when using the 445 nm diode laser with initiated and non-initiated tips. Bovine tongue slices measuring 5 mm in thickness were placed in between two microscope glass slides at a distance of 11 cm from a thermographic camera. Fifteen 2 cm long incisions were made along the surface of the soft tissue parallel to the glass slides and the camera capture field. Incisions were performed using a 445 nm diode laser (continuous wave at 2 watts) with 320 μm-thick glass initiated and non-initiated fiber tips for a total 30-second irradiation period. The maximum temperature changes in °C (ΔT) in the soft tissues, as well as the vertical and lateral heat transfer (in mm), were recorded at 10-second intervals for a duration of 30 s, using the thermographic images captured using the infrared camera and a special image analysis software. Descriptive statistical analysis occurred to evaluate the temperature changes over the critical temperature threshold. The maximum ΔT in °C for the initiated lasers was 17.48 ± 9.05 and for non-initiated lasers was 10.72 ± 2.29. The heat transfer in the two groups for vertical/lateral was 7.50 ± 1.4/18.30 ± 4.01 for the initiated lasers and 7.10 ± 1.82/19.24 ± 3.86 for the non-initiated lasers. Initiated tips and non-initiated tips of 445 nm laser present deep penetration depths and high temperatures in bovine homogenous soft tissues. The irradiation period and clinical indication must be strictly followed to avoid complications from overheating in soft tissues.

Received: 29 January 2024 | Revised: 15 April 2024 | Accepted: 23 April 2024

Conflicts of Interest

The authors declare that they have no conflicts of interest to this work.

Data Availability Statement

Data available on request from the corresponding author upon reasonable request.

Author Contribution Statement

Jamie Wu: Software, Validation, Investigation, Data curation, Writing – original draft, Visualization. Ed Gheorghe Roibu: Investigation, Writing – original draft. Wei Hou: Formal analysis. Rafael Delgado-Ruiz: Writing – review & editing. Georgios E. Romanos: Conceptualization, Methodology, Investigation, Resources, Writing – original draft, Writing – review & editing, Supervision, Project administration.