Materials and Methods: Plaque index (PI), gingival index (GI) and probing depth (PD), width of attached mucosa (WAM), mucosal thickness (MT), mucosal recession (MR), marginal bone loss (MBL) and matrix metalloproteinase-8 level were detected around 116 single-tooth implants at the 1st and 3rd years of loading. The implants were categorised depending on WAM and MT as follows: WAM<2 mm (Group A), WAM ≥2 mm (Group B), MT≤1.5 mm (Group C) and MT>1.5 mm (Group D).
Results: Group A exhibited higher values of GI, PD, MR, MMP-8 and smaller values of MT. Mean MBL in group A was greater at the 3rd year. WAM demonstrated negative correlations with GI, PD, MR and MMP-8 level. Group C demonstrated higher GI, PD and MR and lower WAM values. MT showed a positive correlation with WAM and negative correlations with GI, PD, MR and MMP-8 level.
Conclusions: The dimensions of peri-implant mucosa affect clinical and biochemical parameters. Insufficiency of attached mucosa may lead to peri-implant pocket formation, mucosal recession and marginal bone loss.