Microbiological Profile and Human Immune Response Associated with Peri-Implantitis: A Systematic Review

Area of Science:

• Oral microbiology
• Immunology
• Periodontology

Background:

• Peri-implantitis is a significant complication following dental implant placement.
• Understanding the microbiological and immunological factors is crucial for managing peri-implantitis.
• Existing evidence needs synthesis to clarify the distinct responses in peri-implantitis versus healthy implants.

Purpose of the Study:

• To systematically review and synthesize current research on the microbiological and immune responses in peri-implantitis.
• To compare these responses with those observed around healthy dental implants.
• To elucidate the role of microbial shifts and host immune reactions in peri-implantitis pathogenesis.

Main Methods:

• A comprehensive literature search was conducted across MEDLINE, Embase, and Cochrane Library in October 2019.
• Two independent reviewers screened studies and extracted data from full texts.
• A qualitative synthesis was performed due to heterogeneity; meta-analysis was not feasible.

Main Results:

• Forty studies were included, examining microbiota (20 studies) and immune response (19 studies).
• Peri-implantitis is associated with obligate anaerobe Gram-negative bacteria, asaccharolytic anaerobic Gram-positive rods, and other Gram-positive species.
• Elevated levels of pro-inflammatory mediators (IL-1β, IL-6, IL-17, TNF-α) and osteolytic mediators (RANK, RANKL, Wnt5a, MMPs, Cathepsin-K) were observed in peri-implantitis.

Conclusions:

• Peri-implantitis exhibits a complex microbiota, including bacteria, archaea, fungi, and viruses, differing from healthy implants.
• These microbial differences can trigger enhanced inflammatory and osteolytic responses.
• The combined microbial and host immune factors are key contributors to the physiopathology of peri-implantitis.