MMP9 and periodontitis: Though the overall levels of MMP-9 were markedly lower than the results of our study, which might owe to the use of a different diagnostic fluid for analysis (GCF instead of saliva) and other factors, the overall increase in MMP-9 levels can be seen to be elevated by almost twice as much in subjects with type-II DM compared to non-diabetic chronic periodontitis subjects, which is synonymous with our findings.