MMP8 and periodontitis: Also, both MMP13 and MMP8 have been observed to be elevated in patients with peri implantitis.Platelet-derived growth factor (PDGF) supports healing and increased vascular endothelial growth factor (VEGF) expression in epithelialcells and endothelial cells in periodontitis-affected gingiva may be a useful marker for periodontal healing [19].A meta-analysis by Ghassib et al. [11] examined the use of biomarkers inperi-implant crevicular fluid (PICF) to distinguish between healthy implants, peri-implant mucositis and peri-implantitis.