Number of (a) CD68+ total monocytes and pro-inflammatory macrophages; (b) CD163+ anti-inflammatory tissue macrophages; (c) MHC-II+ antigen-presenting cells; (d) total T lymphocytes; (e) mast cells; and (f) activated natural killer cells in the peri-implant tissue of Lewis rats after i.m. implantation of unmodified Ti6Al4V plates (Ti, white boxes), Ti6Al4V plates treated with plasma immersion ion implantation of copper (Ti-Cu, light gray boxes) or Ti6Al4V plates treated with plasma immersion ion implantation of copper and an additional plasma polymerized allylamine film (Ti-Cu-PPAAm, dark gray boxes) after 7, 14 and 56 days. Boxes represent median and interquartile range and whiskers minimum and maximum values; p-values indicate differences in pairwise comparison by non-parametric Wilcoxon signed rank test.