Performance of Threaded Versus Sintered Porous-Surfaced Dental Implants Using Open Window or Indirect Osteotome-Mediated Sinus Elevation: A Retrospective Report

Background: The purpose of this retrospective report was to evaluate the performance of dental implants placed in a teaching environment in patients requiring maxillary sinus elevation.Methods: Threaded (acid-washed or sand-blasted acid-etched) and sintered porous-surfaced (SPS) press-fit implants were used. Sinuses were managed using direct (open window) or indirect (osteotome-mediated) techniques. Records were available for 97 implants in 62 patients. Preoperative subantral bone heights were determined from radiographs, primarily panoramic. Of 69 threaded implants used, 40 and 29 were placed using direct (DTH) and indirect (ITH) techniques, respectively. Twenty-eight SPS implants were placed using the indirect technique. Implant failure rates using the Kaplan-Meier method of analysis and cumulative crestal bone loss (the latter based on bone levels seen in the most recent radiographs) were determined for both types of implants.Results: The mean preoperative subantral bone height for DTH implants was 5.0...