Background and Objective
To assess inflammatory reactions of fibroblasts in the pathophysiology of peri-implantitis, we
compared the pro-inflammatory and matrix-degrading responses of gingival and granulation tissue fibroblasts from periodontally
healthy controls, peri-implantitis, and periodontitis lesions to an in vitro challenge with Porphyromonas gingivalis.
from periodontally healthy, peri-implantitis and periodontitis donors were challenged with viable P. gingivalis. The inflammatory
reactions of fibroblasts were analyzed before and after 6 h P. gingivalis challenge, and 2.5 and 18 h after removal of the
challenge. Gene expression and induction of pro-inflammatory mediators, and matrix metalloproteinases (MMPs) were assessed
by real-time polymerase chain reaction. Protein expression was measured by enzyme-linked immunosorbent assay.
fibroblasts from peri-implantitis and periodontitis lesions expressed higher levels of interleukin (IL)-1β, IL-8, and monocyte
chemotactic protein (MCP)-1 than fibroblasts from periodontally healthy individuals. The P. gingivalis challenge induced expression
of IL-1β, IL-8, IL-6, MCP-1, and MMP-1 in periodontitis and peri-implantitis fibroblasts, but not in fibroblasts from periodontally
healthy individuals. MMP-8 expression was higher in non-challenged peri-implantitis fibroblasts than in fibroblasts from periodontally
healthy individuals. However, the P. gingivalis challenge downregulated MMP-8 gene expression in peri-implantitis fibroblasts.
After removal of the P. gingivalis challenge, peri-implantitis fibroblasts sustained higher induction of IL-1β, MCP-1, and
MMP-1 compared to periodontitis fibroblasts.
Fibroblasts from peri-implantitis and periodontitis
lesions gave a more pronounced inflammatory response to the P. gingivalis challenge than fibroblasts from healthy donors.
They may therefore be involved in the development of inflammation in peri-implantitis and periodontitis. Moreover, the sustained
upregulation of inflammatory mediators and MMP-1 in peri-implantitis fibroblasts may play a role in the pathogenesis of peri-implantitis.