Objective: This paper reports the results of a prospective multicenter clinical study on immediately fully occlusally loaded full-arch screw-retained prostheses with distal extensions (hybrid prostheses) supported by Osseotite implants inserted in edentulous lower jaws.
Method and material: Sixty-two patients were enrolled in four clinical centers. Three hundred and twenty-five Osseotite implants were inserted and occlusally loaded according to an immediate loading protocol. The temporary prosthesis was delivered 4 h from surgery. The final prosthesis was delivered after 6 months. Marginal bone loss was monitored from periapical radiographs using a computerized technique.
Results: Two implants failed to integrate within 2 months of occlusal loading. A cumulative implant success rate of 99.4% was achieved for a period of 12-60 months postplacement (mean 28.6+/-14.1 (SD) months). Crestal bone loss around the immediately loaded implants was similar to that reported for standard delayed loading protocols.
Conclusion: The results of this study suggest that the rehabilitation of the edentulous mandible by an immediate occlusally loaded hybrid prosthesis supported by five to six Osseotite implants represents a viable alternative treatment to classic delayed loading protocols.