More and more people choose to replace missing teeth with dental implants. This product has given us revolutionary changes in the dentists' world, where patients are given a permanent solution without involving other teeth. Assumption of course is that you have enough bone to anchor the implant. Many implants have succeeded, but some have failed. After some years of experience with implants, we face a new challenge; peri-implantitis. This is a growing problem around implants which, at worse, can result in the loss of the implant itself and the bone it sits in. Peri-implantitis is an inflammatory process affecting the tissues surrounding an implant, leading to loss of supporting tissue. It is caused by bacteria which organize themselves in a biofilm, a word often associated with dental plaque. We can define biofilm as a microbial community, enveloped by self-produced extracellular biopolymers. Biofilms may cause fouling of surfaces, clogging of pipes, and contribute to many forms of human diseases (Costerton et al., 1999).