This study reports a case of peri-implantitis correlated with floss fibers trapped by the implant-prosthetic macrostructure. Discrepancy between the radiographic feature and probing depth was the starting point for a correct evaluation. The minimally invasive removal of the trapped material with the aid of a periodontal endoscope resulted in a complete resolution of the peri-implantitis with a stable long-term result (6 years). This case report argues for some reconsiderations in hygienic, diagnostic, and therapeutic approaches in oral implantology. Keywords: diagnosis, endoscopy, floss, nonsurgical therapy, peri-implantitis