Abstract: Peri-implant diseases have a relatively high incidence, and immune-inflammatory responses are closely associated with peri-implant mucositis and peri-implantitis. The complement system is a vital component of the immune system. Its activation not only regulates the initiation and progression of inflammatory responses but also plays a crucial role in bone remodeling. This review summarizes the roles of the core complement components C3 and C5 in various stages of bone remodeling after implant placement, as well as in peri-implant mucositis and peri-implantitis. The aim of the paper was to provide novel insights for the prevention and treatment of peri-implantitis through targeted regulation of complement protein levels.