Randomized, Controlled Histologic and Histomorphometric Evaluation of Implants With Nanometer-Scale Calcium Phosphate Added to the Dual Acid-Etched Surface in the Human Posterior Maxilla

Background: Placement of dental implants in the posterior maxilla has been associated with higher rates of failure that are due, in part, to the poor bone quality of this region. The purpose of the present study was the histologic and histomorphometric evaluation of the bone around a new implant surface treatment created by a deposition of nanometer-sized calcium phosphate particles added to the dual acid-etched surface.Methods: One custom-made 2 × 10-mm site evaluation implant (SEI) with this novel treatment surface (test) and one SEI with the dual acid-etched surface without treatment (control) were placed in the posterior maxilla of 15 patients. All SEIs were retrieved after 2 months and evaluated under confocal laser scanning microscopy (CLSM) and by light microscopy for histomorphometric analysis of the bone–implant contact (BIC).Results: Histologic observations in control SEIs showed formation of new bone around the implant surface; however, it was not always in direct contact with the entire perime...