Immediate placement and loading of dental implants: A human histologic case report

Background: 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. Methods: Two teeth in need of extraction and localized in two symmetric quadrants of one patient were extracted, and dental implants were placed immediately into fresh extraction sites. One of them was connected with a heating abutment (control), whereas the other one was loaded immediately (test) with a resin crown in occlusion with the antagonist teeth. Clinical examinations were made, and radiographs were taken at follow-up visits. After 6 months, control and test implants were removed, together with the peri-implant bone, and a histomorphometric analysis was made. Results: Both implants appeared radiographically osseointegrated and clinically stable at retrieval. Mineralized tissue was found at the implant interface. The percentage of bone-to-implant contact 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 areas of remodeling and some osteons, whereas the bone tissue surrounding the unloaded implant was constituted of only thin bone trabeculae. Conclusions: Immediate loading did not seem to impair osseointegration of an immediate postextraction implant compared to an unloaded postextraction one. Further studies with a larger number of samples are needed to confirm these preliminary results.