Immediate Loading of Implants in the Maxilla: Survival and Bone Loss After at Least 2 Years in Function

Purpose: To compare survival and peri-implant bone loss around immediately loaded surface-enhanced implants in the maxilla supporting single crowns (SCs), fixed partial dentures (FPDs), and fixed full-arch dentures (FFDs). Materials and Methods: The study included all subjects referred for implant treatment in the maxilla followed by immediate loading between November 2004 and 2007 with at least 2 years of follow-up. Smokers were excluded. Implant survival and bone loss were assessed by a calibrated external examiner who compared digital periapical radiographs taken during recall visits with baseline radiographs (day of loading = day after implant placement). An implant was considered successful when bone loss did not exceed 1 mm. Survival of implants supporting SCs, FPDs, and FFDs was compared using the log-rank test. A linear mixedeffect model analysis was used to evaluate bone loss because of clustering of implants in patients. Results: Three hundred six implants were placed in 55 patients (31 women, 24 men; mean age, 57.5 ± 11.4 years; range, 19 to 77 years) and followed for a mean of 35 ± 10.2 months (range, 24 to 58 months). One implant failed, resulting in an overall survival rate of 99.7% on the implant level and 98.2% on the patient level. No statistically significant differences were observed in the survival rates for SCs (100%), FPDs (98%), and FFDs (100%). The overall mean bone loss was 0.27 ± 0.37 mm (range, 0.00 to 2.55 mm) and was not influenced by the prosthetic reconstruction. Conclusion: Immediate loading of fluoride-modified implants in the maxilla is a predictable and reliable treatment option with high survival rates and limited peri-implant bone loss after 2 years. No statistically significant differences were found between implants supporting SCs, FPDs, and FFDs. Parole chiave: bone loss, dental implant, immediate loading, implant survival