Presenting a novel model to visualize the interaction process between blue (445 nm) and infrared laser radiation (810...

Lasers are increasingly being employed in oral surgery, whereby blue lasers are state of the art. Aiming to advance understanding of laser-tissue interactions, this study presents a novel model system for displaying oral mucosa, to analyse effects of all proposed laser types prior to clinical use.

Exemplary, diode lasers with wavelengths of 445 nm and 810 nm were used for the experiments. Based on the histological structure of oral mucosa, the epithelial and the subepithelial connective tissue were simulated using variously modified gelatine layers for 20 test devices (n = 10 for each wavelength). In the simplified setup, each test device (consisting of a glass receptical and tissue model) was irradiated statically in non-contact mode with 2 W CW for 10 s. During the experiment, the thermal development within the tissue model was documented with a thermographic camera at time points 2.5 s, 5 s and 10 s. Additionally, the morphological changes were recorded with a video camera.

For the wavelength 810 nm, the average temperature in the irradiated target area (interface at the simulated subepithelial connective tissue) rose approx. 62 °C. For the wavelength 445 nm, there were clear thermal changes at this interface leading to an incision of the simulated epithelium. Here, a mean temperature of approx. 151 °C was measured.

The study results underscore that this tissue modelling is a promising approach to display laser-tissue-interactions in oral mucosa prior to clinical use.

The clinical use of laser technology requires preclinical experience and basic knowledge regarding the tissue-interaction process to ensure patient safety. This investigation is an approach to visualize the different effects appear by the use of two representative laser wavelengths 445 and 810 nm in oral soft tissue surgery.