Human histologic assessment of a platform-switched osseointegrated dental implant.

This case report examined crestal bone level maintenance surrounding a platform-switched implant that was retrieved due to prosthetic difficulty. The retrieved platform-switched implant threads demonstrated tight contact with the surrounding bone and demonstrated both radiographic and histologic features that were indicative of successful osseointegration. Very high bone-to-implant contact (BIC) without epithelial downgrowth to the implant thread was noted. The BIC consisted of a combination of newly formed bone and native bone. The buccal and lingual bone levels coincided with the original platform position noted at the time of the surgery, and did not appear to resorb at all. The result of the present investigation confirms the maintenance of the crestal bone level for platform-switched implants.

Sinus graft with biogran, autogenous bone, and PRP: a report of three cases with histology and micro-CT.

Three sinuses were grafted with a bioactive glass bone substitute (Biogran) mixed with autogenous bone retrieved from intraoral donor sites. In two of the three sinuses a platelet-rich plasma (PRP) gel was added to the graft. Bone biopsies retrieved after 5, 6, and 15 months were analyzed. Micro-computerized tomography (micro-CT) values of total bone volume/total volume (TBV/TV) were very reliable compared to histomorphometry. Biogran mixed with autogenous bone and PRP seems to have a positive effect in sinus grafting, with TBV/TV values ranging between 40% and 68%. Micro-CT results have never been compared with histomorphometry for the evaluation of grafted biomaterials. Micro-CT evaluation of some morphometric parameters was difficult, because the radiodensities of Biogran and a certain grade of bone mineralization were similar.