Different populations with adult periodontitis have been investigated for IL-1 genotypes. The aim of the present study was to investigate this genetic association in 2 forms of periodontitis: early onset- (EOP, n = 12) and adult periodontitis (AP, n=18). EOP patients were selected according to clinical parameters and radiographs (age Keywords: periodontitis, periodontal diagnosis, genetic polymorphisms, 1L-10 polymorphism, polymerase chain reaction