Lasers Med Sci (2009) 24:961–970
DOI 10.1007/s10103-009-0676-1

The increased annual placement of oral implants around the world is also associated with a higher number of complications, such as pathological reactions in the soft tissue surrounding the implant and peri-implant bone defects with continuous loss of supporting bone. Bacterial contamination of implant surfaces is a common reason for implant failure. The modern concepts of clinical treatment for periimplantitis are not well studied and sometimes do not lead to successful results.

Ideally, bone-to-implant contact should be increased histomorphometrically, and implants should become reosseointegrated. At present, there is no evidence that antiinfective treatment of implant surfaces prolongs the longevity of an implant.

In the past few years a wide spectrum of indications in modern implant dentistry has been proposed for laser systems. In general, lasers can be used in oral implantology for second-stage surgery of submerged implants, surgery to establish the health of soft tissue surrounding the implant,decontamination of titanium implant surfaces, and, experimentally, for implant site preparation. There is a potential interest in the clinical use of the 980 nm diode laser, which has excellent properties of incision, excision and coagulation of the soft tissues. Intraoperative and postoperative clinical findings were excellent, due to its sufficient cutting abilities, precise incision margin, good coagulation effect,and extremely small zone of thermal necrosis in surrounding tissues.

According to recent literature concerningthe application of different laser wavelengths in the
treatment of peri-implant lesions, the use of CO2 laser (cw as well as pulsed mode) and diode laser (especially 980 nm)seems to be effective against bacteria without changing the
implant surface pattern, as shown by scanning electron microscopy. It has also been noted that irradiation of the implant does not significantly increase the temperature of the implant body. In this respect,Kato et al. noted a slight temperature increase, which did not negatively influence the attachment of fibroblasts or osteoblasts to the implant surface. With regard to the impact of the laser on the tissue surrounding the implant, there is decreased penetration depth due to absorption of the carbon dioxide radiation by the high water content of the mucosa.Both laser systems also showed excellent results in surgical procedures such as excision, incision and coagulation of soft tissues. Laser was advantageous in comparison with
conventional methods, such as scalpel or electrosurgery,because of reduced pain and lack of haemorrhage.Furthermore, electrosurgery may damage the implant surface.

The Er:YAG laser also showed a bactericidal effect,which could be used for peri-implantitis therapy,although some authors observed modifications of the implant surface after irradiation. Based on the findings in recent literature, the Er:YAG laser may be used clinically
for implant site preparation with good results for osseointe gration and bone healing, and with a statistically significant higher percentage of bone-to-implant contact than that with conventional methods of site preparation.

The Nd:YAG laser produces sufficient decontamination in terms of sterilization of the implant surface. The application of Nd:YAG laser for treatment of periimplantitis, hyperplastic mucositis and second-stage surgery of submerged implants is contraindicated, due to the
significant increase in the temperature during laser irradiation, the extensive melting of the implant surface and the higher penetration depth of the laser beam.