Absorption and diffusion of a 645 nm diode laser beam in the bone. An ex vivo study

The present preliminary ex vivo study aims to assess the possible interaction between complex biological systems and laser light, through irradiation of different hard tissue samples. A 645 nm wavelength diode laser was adopted to perform the present evaluation. Due to known similarities to human tissues, swine tissue samples were used. Two samples of cortical bone measuring 4.4 mm and 4.7 mm of thickness and 2 samples of spongeous bone measuring 2.45 mm and 2.9 mm were harvested for the analysis of hard tissues. Mean absorption values were as follows: 128.82 mW standard deviation 8.74 for 2.45 mm spongeous bone sample; 132.34 mW standard deviation 7.66 for 2.9 mm spongeous bone sample; 140.59 mW standard deviation 5.97 for 4.4 mm cortical bone sample and 152.20 mW standard deviation 3.36 for 4.7 mm mucosa and cortical bone sample. Red-light laser with 645nm wavelength has the ability to reach cells in each layer of measured tissues.