A number of candidate gene studies showed that IL1A, IL1B, IL4, IL6, IL10, TNFA, FcγR, VDR, TLR2, TLR4, and MMP1 [60,61,62,63,64,65,66,67,68,69] were the main genes associated with periodontal disease. This evidence concerns the gene IL1A and periodontal disorder.