Retrospective Study of the Survival and Associated Risk Factors of Wedge-Shaped Implants

Purpose: To assess the long-term behavior of wedge-shaped implants and evaluate the influence of the associated risk factors on implant survival rates. Materials and Methods: A retrospective review of clinical records of patients treated with wedge-shaped implants between 1992 and 2011 was conducted. Data on patient sex, age, smoking habits, and history of periodontitis; details of implant length, diameter, angle, and location; and data on surgical, reconstructive, and prosthetic procedures, and systemic disease were selected for analysis. Results: A total of 1,169 implants placed in 154 patients (mean age 55.17 ± 11.33 years) were evaluated. Women received 637 implants, and men received 532 implants; 60.4% were placed in patients who were undergoing periodontal maintenance care, 17.9% in smokers, 17.7% in hypertensive patients, 5.7% in diabetic patients, and 4.4% in cardiac patients. The mean overall survival for implants was 194.26 ± 9.91 months. Seventy-three implants were lost: 3 before implant loading and 70 after loading. The cumulative survival rates at 5 and 10 years were 96.6% (confidence interval [CI]: 95.5% to 97.7%) and 91.8% (CI: 90.1% to 94.1%), respectively. Univariate analysis indicated tobacco smoking (P = .014) and implant location (P .001) as significant risk factors for implant failure. The multivariate analysis showed tobacco smoking (P = .016), location (P = .001), and male sex (P = .038) as significant, and the latter factor was associated with previous periodontal disease. Conclusions: Overall survival of the wedge-shaped implant showed good long-term results. Male sex, tobacco smoking, and posterior maxillary location were associated with a greater risk of implant failure.