Objectives: The purpose of this study was to evaluate differences in marginal bone level and survival rates of implants placed in lateral-window sinus floor elevation (LSFE) sites compared to other sites. Method and materials: Patients with a history of LSFE and subsequent implant placement were identified. Clinical and radiographic data were collected by two calibrated examiners and divided into three cohorts for the analysis, including (1) implants placed in the LSFE-grafted sinus, (2) implants placed in the maxilla at sites other than grafted sinus, and (3) implants placed in the mandible. Implant survival rate and marginal bone level were recorded and calculated. The potential influences of several host-, implant-, and surgery-related factors on implant survival rate and marginal bone level were analyzed using generalized estimating equations. 
Results: 427 implants from 99 patients (63.8 ±12.5 years) with an average follow-up period of 32.3 ± 29.2 months were analyzed. The cumulative implant survival rate at the grafted sinuses was 93.63%. Mean marginal bone level was 0.44 ± 0.79 mm, 0.84 ± 1.21 mm, and 0.85 ± 1.16 mm for implants in group 1 (n = 142), group 2 (n = 129), and group 3 (n = 147) (P = .01). The majority of marginal bone loss occurred within the first 12 months after implant placement. The status of smoking and periodontal disease did not impact implant survival rate or marginal bone level for any group (P > .05). Neither sinus membrane perforation nor grafting materials affected marginal bone level (P > .05) in group 1.
Conclusion: The utilization of LSFE and the presence of sinus membrane perforation during LSFE had no negative impact on implant outcomes.