Survival and complications: A 9- to 15-year retrospective follow-up of dental implant therapy.

Long-term follow-up of oral implant therapy seldom report all biological and technical complications. The objective of this study was to evaluate the long-term (9-15 years) outcome after dental implant therapy, assess survival and complication rates. In addition, to identify the risk indicators of these complications at patient and implant levels. Patients (n = 376) treated with dental implants (n = 1095) between 1999 and 2005 at a specialist clinic in Stockholm, Sweden, were included. Longitudinal data were collected retrospectively from digital dental records. A subset of the included patient underwent a clinical examination at the 9-15 years follow-up (n = 163). Chi-square tests, Kaplan-Meier analyses and the general estimating equations (GEE) procedure were adopted for multilevel analyses. The cumulative implant survival rate up to 15 years was 82.6% (SE 4.1%). The prevalences of biological and technical complications at patient level were 52% and 32%, respectively. In total, 763 complications occurred, 65% of patients experienced at least one complications. Implant loss occurred significantly more frequently in subjects with a history of treated severe periodontitis Stage III-IV (P = .008) and in cases when complications were registered during implant surgery (P = .010). Smoking was a significant risk indicator for peri-implantitis (P = .006). The long-term implant survival and complication rates at patient level were 83% and 79%, respectively. Implant loss was significantly more frequent for subjects with a history of treated severe periodontitis and if complication was registered during implant surgery. Smoking was a significant risk indicator for peri-implantitis.