The inflammatory lesions that develop in the tissue around dental implants are collectively recognized as peri-implant diseases (Albrektsson & Isidor 1994). Manifestation of peri-implant diseases represents a widespread problem. Cross-sectional studies reported that peri-implant mucositis, I.E. bleeding on probing without concomitant alveolar bone loss, occurred in about 79% of the subjects and 50% of the implants (Roos-Jansåker et al. 2006). The prevalence of subjects with peri-implantitis varied between 25% and 45% in several publications in accordance with the selected population (Karoussis et al. 2004a, Brägger et al. 2005, Fransson et al. 2005, Roos-Jansåker et al. 2006, Fransson et al. 2008).