MMP3 and periodontitis: As outlined in Table 3, in the comparisons between the three groups, all biomarkers were found to be significantly different (p value < 0.05), except for: (i) OPG and IL-8 between the health and gingivitis groups; (ii) IL-8 between the health and periodontitis groups; and (iii) MMP-3 between the gingivitis and periodontitis groups.