Pages 408-420, Language: EnglishSennerby / RoosPurpose: This article reviews the current knowledge about the influence of surgical factors on implant failure in routine cases and in those where implants have been used in conjunction with bone augmentation procedures. Materials and Methods: Clinical reports published in major scientific journals served as the basis for this review. Results: With few exceptions, most clinical reports were on screw-shaped titanium implants. High failure rates are associated with poor bone quality and the use of short implants in the athrophic maxilla, irradiation, and bone-grafting procedures of the athrophic maxilla. Evidence for high long-term failure rates of press-fit cylinders was found. Moreover, limited clinical experience, lack of preoperative antibiotics, and smoking may lead to higher failure rates. Conclusion: There is a need for further research to increase the success rates in the severely resorbed maxilla. Because of a lack of proper documentation with respect to the great majority of currently used oral implant designs, the influence of different factors and their long-term results remain unknown.