Peri‐implant mucositis has been defined in previous workshops as an inflammatory lesion of the mucosa surrounding an endosseous implant without loss of supporting peri‐implant bone. The important criteria for the definition of peri‐implant mucositis are inflammation in the peri‐implant mucosa and the absence of continuing marginal peri‐implant bone loss. The clinical sign of inflammation is bleeding on probing, while additional signs may include erythema, swelling, and suppuration (Table 1). The clinical case definition of peri‐implant mucositis has been addressed in another review prepared for this workshop.