Peri-Implantitis: Biofilm-Induced Disease or Prosthetically Driven Complication?

Peri-implantitis is a prevalent biological complication of implant therapy; however, whether it should be understood primarily as a biofilm-induced infection or as a consequence of prosthetically driven mechanical factors remains unclear. This narrative review synthesizes microbiological, biomechanical, and prosthetic evidence to address this question from an interdisciplinary perspective. Peri-implant biofilms occupy a distinct microbial niche, and their dysbiotic transition and the accompanying host response appear to be central to disease initiation, while an implant-directed foreign body reaction may contribute independently to bone loss. Occlusal overload, residual cement, and unfavorable emergence angles or contours do not independently initiate disease but consistently accelerate progression once inflammation is established, with wide emergence angles and cemented restorations with residual material showing particularly strong associations with the marginal bone loss. Epidemiological data confirm a multifactorial risk profile in which a history of periodontitis, smoking, and systemic conditions interact with local biofilms and prosthetic factors. Clinically, these findings support the integration of restorative, periodontal, and relevant endodontic assessments into implant treatment planning and long-term supportive care, as prosthetic design functions as a modifiable determinant of peri-implant health rather than a purely esthetic or mechanical consideration.