Association of matrix metalloproteinase (MMP)-1, 3, 9, interleukin (IL)-2, 8 and cyclooxygenase (COX)-2 gene polymorphisms with chronic periodontitis in a Chinese population

► MMP-1, MMP-3, MMP-9 and IL-8 polymorphisms might be suspicious of CP onset. ► Firstly found an association of MMP-3,-9 and IL-8 polymorphisms with CP in Chinese. ► The CP patients' genes are related to clinical parameters and the serum cytokines. ► Before restoration, dentists should consider genotype and phenotype of CP patients. ► MMPs, cytokines and COX-2 genes showed significant differences between the groups.