Effektivität und histologische Auswertung von Gewebeproben nach Bearbeitung mit einem 445nm Halbleiterlaser

When using a 445nm semiconductor laser for incisions precise cutting lines and a moderate, local heat exposure is described. Therefor the purpose of this study was the histologic observation of tissue examples after the incision with a 445nm diode laser. Forty mucosal flaps from the oral vestibule of twenty pig jaws were dissected to be mounted on a mechanical linear unit. The hand piece of a high frequency electrosurgical unit, 970nm diode laser and 445nm diode laser where mounted on the slide of the linear unit. Therefore, all incisions could be operated with the same speed and distance to the tissue surface. Eight incisions where performed on each of the two mucosal flaps from one jaw: (I-III): 445nm Laser without blackened tip, 90° in tissue contact at 1, 2, and 4W cw, (IV-V): 445nm Laser without blackened tip, without tissue contact (1mm) at 2 and 4W cw, (VI): 445nm Laser without blackened tip, 45° in tissue contact at 2W cw, (VII): 970nm Laser with blackened tip, 90°, in tissue contact at 3W cw, (VIII): High frequency electrosurgical unit with a straight tip, 90°, in tissue contact at 50W. The histological analysis took place after HE-staining of the embedded specimen at a 35-fold magnification. Comparing the depth of the incisions, a significant difference depending on wavelength and chosen parameter setup could be observed. The highest depth was seen with the 445nm Laser in tissue contact at 2W cw (p<0.05). The lowest depth was measured after using the HF electrosurgical unit. Using a 445nm semiconductor laser, a higher cutting efficiency compared to a 970nm diode laser and a HF-electrosurgical unit can be expected. Also the non-contact-mode shows acceptable clinical incision depth without signs of extensive necrosis.