Osseointegrated dental implants are an inseparable treatment option in the armament of reconstructive dentistry, and when maintained appropriately, can survive life-long. The biocompatibility and biostability properties of those devices are paramount for their long-term survival and optimal functional performance in an otherwise challenging oral environment. At the same time, the implant's metallic surface exposed to the oral cavity is a novel oral site for microbial colonization and biofilm formation. This biofilm will consequently challenge peri-implant tissues to produce an inflammatory response that can be detrimental for the integrity of the tissue, and consequently the longevity of the implant. Therefore, early risk indicators of peri-implant health may have paramount diagnostic and prognostic value for ensuring early prevention and maintaining long-term peri-implant health. This chapter discusses clinical parameters as well as microbiological and immunological indicators of risk factors for the establishment of peri-implant mucositis and early peri-implant bone loss.