Peri-implantitis are inflammatory lesions which effect the tissue near the implant in function. It is the main cause which dues to failed implant. Its clinical manifestations are fistula, bleeding or suppuration on probing, bone loss in the X-ray picture. There are many reasons for peri-implantitis, such as bacterial contamination, overloading. Besides biomechanical factors, genetic susceptibility, patients who have a history of periodontitis and smoking status are more at risk for peri-implant diseases. Most scholars think that smoking and a history of periodontitis may affect implant success rates, but they do not agree on the relationship between genotype and periimplantitis. This article is an overview about the polymorphisms in the interleukin-1（IL-1） gene, the history of periodontitis and smoking status, researching their relations with peri-implantitis.
