Follow-Up of the Sinus Membrane Elevation Technique for Maxillary Sinus Implants without the Use of Graft Material

Background: There is a limited amount of studies evaluating long-term results of the sinus membrane elevation technique for bone formation around implants in the maxillary sinus floor without the use of bone graft material. Purpose: To investigate the long-term results of this technique with regard to implant survival and bone gain in the maxillary sinus floor. Materials and Methods: A retrospective study was conducted on patients who had undergone the surgical procedure from November 2001 to August 2008. Thirty-six patients with a total of 87 implants (ASTRA TECH Implant System (TM)) in 53 sinuses were examined. After a submerged healing period of 6 months and at least 12 months of loading, the patients were examined clinically and radiologically. Implant stability was measured using resonance frequency analysis (RFA). Results: The mean follow-up time was 4.6 years (range 1.5-7 years). Five implants were lost giving a survival rate of 94.3%. Subantral preoperative vertical bone levels were in the range of 1 to 10 mm. The average bone gain at the sinus floor was 6 mm. The 55 fixtures eligible for RFA displayed a mean implant stability quotient of 77 (range 56-85.5). Conclusion: The present study illustrates the long-term reliability of the technique.