Si M, et al. - In this retrospective study, researchers assessed the clinical and radiographic results of small-diameter implants (SDIs: diameter <3.5 mm) supporting fixed prostheses without bone augmentation in the posterior region, as well as examined the potential influencing factors related to SDI failures. After 2 to 12 years of follow-up, clinical and radiographic data of 243 SDIs in 156 patients were retrospectively assembled. According to results, no implant fracture was identified in this analysis. The only factor that significantly influenced SDI failures was the implant type (bone-level or tissue-level). Investigators observed that predictable long-term clinical outcomes were achieved by SDIs supporting fixed prostheses in the posterior region. However, if possible, tissue-level titanium SDIs should be avoided.