Optimization of 980nm laser radiation parameters for fractional therapy of oral mucosa
Pathologies of the oral mucosa are a common reason for seeking dental care. Fractional laser therapy is a modern, effective, minimally invasive, and safe method of treatment and can be a promising method of tissue regeneration in dentistry. Traditional methods of treating pathologies of the oral mucosa, such as scars and Stillman's cleft, are quite effective, however, the use of most of them is associated with extensive surgical intervention and the risk of complications. It is known that a laser with a wavelength of 980 nm stimulates the regeneration of the oral mucosa of animals [1,2]. The aim of present study is to find a range in which the parameters of 980 nm laser radiation are optimal for fractional therapy of the oral mucosa.
Optical and thermophysical models of the animal (rat) oral mucosa have been developed. Simulation was carried out using TracePro Expert 7.0.1 Release (Lambda Research Corporation, USA) и COMSOL Multiphysics (COMSOL Inc., USA). The calculation of light propagation and temperature distribution in animal oral mucosa as a result of fractional laser action with a wavelength of 980 nm has been performed. The distribution of the Arrhenius function is calculated.
In an experiment on animals (rats), a histological study of the oral mucosa of the animal was carried out in vivo after fractional treatment to laser radiation "StLase" (Dental Photonics. Inc, USA) with a wavelength of 980 nm.
The results of calculations on models of the animal oral mucosa are compared with the data of histological examination.
Optical and thermophysical models of the human oral mucosa have been developed. The criteria for optimal fractional laser impact on the human oral mucosa have been formulated. First criteria - do not overheat the mucosal surface above 100оС in order to avoid its ablation. Second criteria - to act on the lamina of the mucous membrane, in which the defects requiring correction are concentrated, i.e. the depth of the damaged area should be greater than the thickness of the epithelium of the oral mucosa. Third criteria - do not damage the bone, because its degradation can lead to tooth loss, i.e. the area of damage should be less than the thickness of the oral mucosa.
As a result of optical and thermophysical modeling, the optimal ranges of the diameters of the fiber-optic tip, the power and duration of a laser pulse with a wavelength of 980 nm were determined for fractional laser treatment of the human oral mucosa.
1.Gladkova N. D. et al. Histological response of oral mucosa on fractional laser photothermolysis in animal experiments //Modern Technologies in Medicine. – 2012. – Т. 3. – С. 7-11.
2. Belikov A.V., Ermolaeva L.A., Korzhevsky D.E., Sergeeva E.S., Semyashkina Y.V., Gusel'Nikova V.V., Antropova M.M., Fedotov D.Y. Optical and morphological investigation of oral cavity mucosa regeneration after the fractional treatment by radiation of 980 nm diode laser // Proceedings of SPIE - 2019, Vol. 11065, pp. 1106513
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