Originally, the main principle of cutting soft tissue by dental diode laser is to heat the tissue by touching with a hot tip end. The high temperature produced by converting light energy into heat energy at the end of tip can reached high enough to vaporize the soft tissue. The principle of the 450nm blue laser is a little different. It uses the ultra-high absorption in human tissue to increase the tissue temperature and directly cause tissue vaporization, so the cutting efficiency is much higher.
The absorption constant shows 450nm wavelength has a high level of absorption in melanin and hemoglobin. Furthermore, it also has high absorption in collagen. But its absorption in water is lower than conventional infrared diode lasers’. Besides, scattering in the blue light spectrum also increases. These effects mean that, compared with the infrared diode lasers, 450nm wavelength has higher absorption in human tissue so it can it can directly act on the human tissue to vaporize the tissue. In this way, the working effectiveness is higher at the same power settings when you use 450nm blue laser.
Before the beginning of excision or incision procedure, tip initiation is an essential process if you use conventional infrared diode lasers. Initiation of the fiber tip should be accomplished by activating the laser while touching the tip to a dark chromophore. Though many practitioners use articulating fiber or cork, neither produces a satisfactory, complete or thorough initiation. The best initiation is performed by using black ink suitable for painting onto glass surface and a good quality, very thin paintbrush. The paintbrush is dipped into the ink and painted onto the tip of the laser fiber and allowed to dry for 30 seconds. The purpose is to concentrate heat energy at the fiber’s tip, increasing the thermal interaction with the tissue and accelerating debridement.
Obviously, the tip initiation is not easy and to achieve the best initialization effect, it is even less likely. Poor initiation will greatly reduce the cutting efficiency. While 450nm doesn’t has this requirement and its limit, because of high level of absorption in melanin and hemoglobin, tip initiation is not needed and power setting could be much lower.
With regard to tissue vaporization, intensive absorption may improve cutting effects. The increased level of absorption in comparison with conventional diode lasers could lead to a reduction of the thermal side effects outside the work area. The specific absorption constants related to blue light are therefore a basis for an effective limiting of biological side effects outside the radiation field.
The absorption of light at 445 nm in water is low. This means that, during surgical procedures, the radiation energy is almost completely transmitted through the non-pigmented mucin layer. Therefore, the cutting procedure starts immediately at the accurate operation area, with very limited impact on the nearby tissue.
Because of High cutting efficiency with lower power setting and fewer thermal side effects, 450nm blue laser is very good for wound healing after excision or incision procedure. Besides, antimicrobial effects are highly exceeded in comparison with infrared radiation and promote an effective disinfection of contaminated tissue areas. In this way, the blue light can be used to prevent wound infections.