Fig. 3.

Association between the levels of P. gingivalis and TNFα/ miR-155 and between TLR-4 and miR-155 in patients with periodontitis with (G1) and without diabetes (G2) diagnosed with COVID-19. The scatter diagram depicts that in both groups, the correlation between P. gingivalis abundance and mRNA expression of TNFα or miR-155 was significantly negative (A-D). At the same time, the relationship between transcription levels of TLR-4 and miR-155 was significantly positive in G1 and negative in G2 (E-F). Spearman correlation coefficient (r) and exact p-value are shown.