Intracellular infection of Cutibacterium acnes in macrophages of extensive peri-implantitis lesions: A clinical case series.

Cutibacterium acnes is a facultative anaerobic, gram-positive rod, and a commensal bacterium of the body surface including oral cavity. A causal relationship between C. acnes and chronic granulomatous diseases, such as sarcoidosis and orthopedic implant-associated infections, has been previously reported.