A human histologic report of an implant placed with simultaneous sinus floor elevation without bone graft

A titanium implant with an acid-etched surface was placed simultaneously with sinus floor elevation in a severely resorbed ridge of a 52-year-old man. The height of the residual crest was less than 3 mm, and no bone substitute was used to graft the sinus cavity. Six months after placement, the implants were uncovered, and no signs of mobility were recorded. The implant at the second molar site and surrounding bone were removed for prosthetic convenience. The specimen was harvested and processed for undecalcified histologic analysis. Poor bone quality around the implant was evident, characterized by large marrow spaces and scarce trabeculation. Signs of osseointegration could be seen mainly toward the apical third of the implant. A cortical wall was present apical to the implant, suggesting the formation of a new sinus floor. The relationship between the histologic evidence and possible clinical implications are discussed.