A 12-year Retrospective Analytic Study of the Implant Survival Rate in 177 Consecutive Maxillary Sinus Augmentation Procedures

Purpose: This retrospective study sought to demonstrate the outcome of maxillary sinus elevation surgery in a series of 177 procedures performed over 12 years and to determine the existence of variables that could independently predict implant survival. Materials and Methods: A retrospective descriptive and analytic study of a series of maxillary sinus elevation procedures performed between 1996 and 2007 was undertaken. The sample was composed of patients with severe atrophy of the posterior maxilla who had been rehabilitated with osseointegrated implants placed in grafted maxillary sinuses. Several features of the patients (smoking habit, presence of comorbidities, and previous oral carcinoma) and of the surgical procedure (grafting material, associated procedures, associated materials, simultaneous/delayed implant placement, and complications) related to implant survival or failure were monitored during the follow-up period. Implant survival and the existence of variables that could predict implant survival independently were analyzed statistically. Results: One hundred seventy-seven sinus augmentation procedures were performed in 119 consecutive patients (mean age 50.02 years; SD 11.5). Of the 272 implants placed in sinus-augmented regions, 19 were lost. The mean follow-up period was 60.7 months (SD 36.5). The overall cumulative implant survival rate was 93% after 5 years. The multivariate analysis showed that the presence of complications related to the sinus augmentation procedure (membrane perforation and sinusitis) and peri-implantitis were factors in predicting implant failure. Conclusions: On the basis of this retrospective analysis, it might be concluded that sinus augmentation is a very versatile procedure. Its efficacy and predictability in terms of implant survival rate is extremely high and independent of the graft material, surgical technique, associated comorbidities, smoking habits, and timing of implant placement. Complications such as membrane perforation, sinusitis, and peri-implantitis appeared to influence implant failure. Keywords: implant survival rate, multivariate analysis, sinus augmentation, univariate analysis