Peri-implant mucositis is a condition caused by the build-up of bacteria on the dental implant, leading to inflammation of the surrounding gingival tissue. It is usually the result of poor oral hygiene but can also be attributed to smoking or a history of periodontitis. When peri-implant mucositis is left untreated, it can progress into a more severe condition called peri-implantitis, which is characterised by increased inflammation and bone loss surrounding the implant. This may result in the implant becoming loose in the deteriorated bone and requiring replacement.