Mini-invasive Implant Placement in Combination with Maxillary Sinus Membrane Perforation During Transcrestal Sinus Floor Elevation: A Retrospective Study

The aim of this retrospective study was to report preliminary outcomes of a modified technique for transcrestal sinus floor elevation with simultaneous implant placement. A total of 165 implants were placed in 110 patients using a modified Summers technique. During implant site preparation, after fracturing the sinus floor, a small perforation of the membrane was made using the first osteotome. After grafting with anorganic bovine bone mixed with venous blood, standard-length implants were inserted. The prosthetic phase occurred after 4 to 5 months. Patients were followed for at least 2 years after loading. During the follow-up, sinus condition was assessed by cone beam computed tomography. Periapical radiographs were taken to assess graft height and peri-implant bone levels. Three implants failed within 2 months of placement, yielding an overall implant survival of 98.2%. The mean follow-up was 38.3 months (range: 28 to 60 months) from placement. All other implants were stable and peri-implant soft tissues were healthy throughout the observation period. Peri-implant bone loss averaged 0.62 ± 0.26 mm after 1 year of function. No biologic or biomechanical complications occurred. No evidence of graft material dispersion into the sinus space was detected, except for two cases that resolved spontaneously. After 1 year of loading the graft height averaged 4.8 ± 1.3 mm above the sinus floor level. In the presence of sinus membrane perforation, the proposed modified osteotome technique may allow a predictable rehabilitation of the atrophic posterior maxilla by means of standard length implants without the occurrence of adverse events.