Immediately loaded postextraction implants: a human histologic case report.

The possibility of immediately loading postextraction implants was proposed recently. However, histologic evidence of osteointegration in such cases is still lacking. In this case report, two implants placed into fresh extraction sites, one immediately loaded and the other one unloaded, were compared clinically and histologically. Two teeth in need of extraction and localized in two symmetric quadrants were selected. Baseline clinical and radiographic exams were performed. Teeth were extracted and dental implants immediately inserted into fresh extraction sites. One of them was connected with a healing abutment (control), while the other one was immediately loaded (test) by a resin crown. Clinical and radiographic examinations were performed at follow-up visits. After six months both control and test implants were removed, together with the peri-implant bone, and histologically examined. Both implants appeared radiographically osseointegrated and clinically stable at retrieval time. No sign of failure was found. Histologically, mineralized tissue was detected at the implant interface. The bone-to-implant contact percentage in the control and test implants was 58 ± 4.0% and 52 ± 3.2%, respectively. In the loaded implant a more compact, mature, well-organized peri-implant bone was found, with many remodelling areas and some osteons, whereas the bone tissue surrounding the unloaded implant was constituted only by thin bone trabeculae.Immediate loading did not seem to impair osseointegration of an immediately loaded postextraction implant, compared to an unloaded postextraction one. Further studies, with a larger number of samples, are needed to confirm these preliminary results.