Inflammatory and regenerative processes in the patients with developing periimplant mucositis (PM) and peri-implantitis in comparison with the patients with severe periodontitis taking into account the expression of VEGF (vascular endothelial growth factor), SMA (myofibroblastic cell differentiation marker), and Ki-67 (proliferative activity marker). This evidence concerns the gene SMN1 and Peri-Implantitis.