Histologic analysis of an immediately loaded implant retrieved after 2 months

Human biopsy of immediately loaded implants is the most important way to determine the occurrence of osseointegration. Implants inserted in sites with poor bone quality have been associated with lower success rates. The aim of this study is to document the early healing processes in a man around an immediately loaded implant retrieved after a 2-month loading period. An implant was inserted in the mandible of a 32-year-old patient and was loaded into a nonfunctional loading mode with a fixed provisional prosthesis the same day of the implant surgery. After 2 months, because the patient had difficulty accepting the implant, the implant was retrieved with a 5-mm trephine drill. Before retrieval, the implant appeared to be clinically osseointegrated, and no mobility was present. The preexisting bone quality was type D4. The implant was surrounded by newly formed bone lamellae with a width of 200 to 400 microm. In many areas it was possible to observe osteoblasts producing osteoid matrix directly on the implant surface. Bone-to-implant contact percentage was 71% +/- 3.2%. Even in a poor bone site and after a healing period of only 2 months, we observed a high bone-to-implant contact percentage. We can confirm that immediately loaded implants placed in soft spongy bone after a 2-month healing period can present mineralized tissue at the interface.