IL1B and Peri-Implantitis: With regard to the IL-1B+3954 polymorphism, He et al. (2020) observed that, in the peri-implantitis group, the allelic frequency for the C allele was 68.8% and for the T allele was 31.2%, while in the health group the allelic frequency was 79.9% for the C allele and 20.1% for the T allele.