Dental implants have become a more popular and common therapy in dentistry in order to replace missing teeth nowadays, which means problems would develop with time like peri-implant disease. There are multiple aetiology factors including local and systemic factors. Acknowledgement of the factors is important to avoid possible complications after implant placement. It is also important to treat peri-implant disease to reconstruct of patients' oral health. Perimucositis can be treated by conservative treatment alone. However, periimlantitis needs to be treated by the combination of both conservative and surgical methods.