The first long-term successful outcome of short dental implants was demonstrated by Frieberg et al. in 1991, however, the definition of “short” implants is still controversial and without uniform consensus nowadays. The specific aim of this review was to evaluate and to compare cumulative survival rate (CSR) of short dental implants of the two groups. The survival rate of short dental implants was the primary outcome variable to be extracted and analyzed. An electronic search was conducted through the Medline (PubMed) database of the National Library of Medicine, and EMBASE to find all relevant articles published between January 1, 1990, and April 30, 2015. The electronic search identified 347 publications, which were all carefully screened by title and abstract. About 65 articles qualified for a thorough full-text analysis: 35 studies were excluded because CSR% was not calculable. Finally, 30 studies with relevant data on CSR were selected to be included in this review. Articles were divided into two groups: All relevant articles published between 1991 and 2000 as Group 1 and between 2001 and 2015 as Group 2. In Group 1 CSR was 83.53% ± 19.46%, a considerable statistically significant difference compared to 93.65% ± 7.94% of Group 2. This review further identified the causes of failure: In Group 1 the majority of short implant failures occurred early, within the first 4 months, for an insufficient quantity of bone tissue. In Group 2, causes of early failures considered were low bone quality while prosthetic reasons were responsible for delayed failures
