Short Implants in Maxillae and Mandibles: A Retrospective Study With 1 to 8 Years of Follow-Up

Background: The aims of this study are to evaluate the long-term survival rates of short dental implants in posterior areas in both jaws and analyze the influence of different factors on implant survival. Methods: A retrospective cohort study design was used. Six hundred and sixty-one patients received 1,287 short implants (<8.5 mm) between 2001 to 2008 in Vitoria, Spain. All implant installations were performed by two experienced surgeons and rehabilitations were done by three prosthodontists. Each implant failure was carefully analyzed. The potential influence of demographic factors, clinical factors, surgery-depending factors, and prosthetic variables on implant survival was studied. Implant survival was analyzed using a life table analysis (Wilcoxon [Gehan] test). Results: The overall survival rates of short implants were 99.3% and 98.8% for the implant and subject-based analysis, respectively. The mean follow-up period for the implants was 47.9 +/- 24.46 months. A total of 9 out of 1,287 implants were lost during the observation period. None of the variables studied resulted in statistical association with implant failure because of the low number of failures. Conclusion: Results of the present retrospective study show that treatment with short implants can be considered safe and predictable if used under strict clinical protocols. J Periodontol 2010;81:819-826.