CyPA and Emmprin play a role in peri-implantitis

Cyclophilin A (CyPA) and Emmprin play important roles in peri-implantitis. However, their roles in the diagnosis and treatment of the disease are still unclear.

The aim of this split-mouth animal study was to describe variable trends of biomarkers during the progression of peri-implantitis and to define relationships among CyPA, Emmprin, and peri-implantitis.

Six male adult Labradors were used. The mandibular premolars and the first molar were extracted, and sixteen implants were placed after 3 months. Peri-implantitis was induced around the implants on one side, which were the test group, and the implants on the other side were included in the control group. Clinical parameters such as probing depth, gingival index, and bleeding index and periapical X-rays were recorded at weeks 0, 2, 4, 6, 8, 10, and 12. Peri-implant crest fluid (PICF) and gingiva around the implants were collected and analyzed by ELISA and real-time PCR, respectively.

The clinical parameters of the test group indicated severe inflammation around the implants. Radiographs showed obvious bone loss beginning at week 4, and it continued over time. The concentration of CyPA in the peri-implantitis group increased at first and then decreased beginning at week 6, and the concentration of Emmprin decreased at first and then increased beginning at week 6. Emmprin, matrix metalloproteinase-9 and Tissue Inhibitor of Metalloproteinase-1 showed similar changes over time. CyPA showed a consistent trend with Interleukin-1β, but showed an opposite trend to Transforming growth factor-β. Both the concentration of CyPA in PICF and gene expression in gingival tissue increased before bone absorption occurred.

Despite the limitations of this study, CyPA may be an early signal for peri-implantitis. A CyPA-Emmprin interaction exists in peri-implantitis and is Emmprin-dependent. Emmprin is related to clinical attachment loss in peri-implantitis.