Survival rates of short (6mm) micro-rough surface implants: a review of literature and meta-analysis

Objective The aim of this review was to test the hypothesis that 6mm micro-rough short Straumann((R)) implants provide predictable survival rates and verify that most failures occurring are early failures. Materials and methods A PubMed and hand search was performed to identify studies involving micro-rough 6-mm-short implants published between January 1987 and August 2011. Studies were included that (i) involve Straumann((R)) 6mm implants placed in the human jaws, (ii) provide data on the survival rate, (iii) mention the time of failure, and (iv) report a minimum follow-up period of 12months following placement. A meta-analysis was performed on the extracted data. Results From a total of 842 publications that were screened, 12 methodologically sound articles qualified to be included for the statistical evaluation based on our inclusion criteria. A total of 690 Straumann((R)) 6-mm-short implants were evaluated in the reviewed studies (Total: placed-690, failed-25; maxilla: placed-266, failed-14; mandible: placed-364, failed-5; follow-up period: 1-8years). A meta-analysis was performed on the calculated early cumulative survival rates (CSR%). The pooled early CSR% calculated in this meta-analysis was 93.7%, whereas the overall survival rates in the maxilla and mandible were 94.7% and 98.6% respectively. Implant failures observed were predominantly early failures (76%). Conclusion This meta-analysis provides robust evidence that micro-rough 6-mm-short dental implants are a predictable treatment option, providing favorable survival rates. The failures encountered with 6-mm-short implants were predominantly early and their survival in the mandible was slightly superior.