Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2017-03-17, 12:41:55 | version 1.38.0
research | Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 energy in the coloured cell walls of the bacteria1–4 and stimulation of wound healing.6–9 Fig. 10: An 11-mm pocket on the buccal side 21. Fig. 11: X-ray shows the deep pocket on 21 and a heavy subgingival resorption distally from 22. Fig. 12: Restitutio ad integrum, clinically. Fig. 13: Radiological health, CO2 positive. Fig. 14: Three years later, a healthy periodontal situation at 21. Fig. 15: A 12-mm active pocket mesially from tooth 33. Fig. 16: X-ray, teeth 33, 34 and 37. Fig. 17: Ten months later: A small recession of the gum. Fig. 18: Ten months later: regeneration of the periodontal bone. laser 1 2017 11 2.2.2 The second treatment session for the patient is normally one week after the first treatment and is done without anaesthesia. The conventional pocket treatment is only an ultrasonic cleaning of the pocket followed by the second laser treatment: First, a diode hardlaser with a wavelength of 810 nm (White Star) is applied directly after the conventional pocket treatment. The output power is 1 Watt in cw mode, and the application time lasts three times 30 seconds for each pocket side. The laser fibre has a diametre of 0.4 mm. The energy is emitted at the fibre end with a divergence angle of about 12°. The fibre is placed at the pocket bottom. In his other hand, the operator holds e.g. a 5 ml syringe with physiological NaCl solution. Before starting the laser, blood in the pocket is washed out with the rinsing solution. To avoid any formation of “hotspots” (Fig. 3) at the end of the laser fibre, the pocket is rinsed simultaneously with the isotonic saline solution during the applica- tion of the laser energy. A “hot spot” is black burned soft tissue at the fibre end. The emitted energy will be absorbed there with an absorption coefficient of about 102 /cm (Fig. 1). For this reason, the fibre end solution as a photosensitiser and a softlaser of 670 nm wavelength having a maximal output power of 300 milliwatt (mW) in continous wave (cw) mode. The Er:YAG-irradiated pocket needs to be completely coloured with the methylene blue solution. After one minute, the pocket is washed out with a 3 % H2O2 solu- tion and then irradiated during one minute with the softlaser at 670 nm and a maximum output power of about 250 to 300 mW from the buccal and oral sides. After the Er:YAG irradiation the pocket is always bleeding because of the intervention by itself and the very low duty cycle37 of the Er:YAG pulse. The blood must be washed out with water or an isotonic saline solution, otherwise the laser energy will be absorbed in the blood and cannot enter deep enough into the pocket tissue. Figure 1 shows that the laser has an ab- sorption coefficient of about 101 /cm for venous blood at 670 nm. The penetration depth of the laser energy is per definitionem the reciprocal value of the absorption coefficient and in our example ~ 10–1 cm or ~ 1 mm. In this layer, about 2/3 of the emitted laser energy is already absorbed (Beer-Lambert absorption law). For the same reason, methylene blue coloura- tion of the outside of the gum must be avoided. The patient must not feel any warmth. The expected ther- apeutic effect is decontamination of the pocket due to formation of oxygen radicals by absorption of the Fig. 15 Fig. 16 Fig. 17 Fig. 18