Background: Short dental implants (≤6 mm) are increasingly used for posterior rehabilitation in patients with limited alveolar bone height. This review examines their survival rates, marginal bone loss (MBL), peri-implantitis, and technical/prosthetic complications compared with standard-length implants. Methods: A narrative review of the literature was conducted using PubMed, Scopus, and Cochrane Library databases. Search terms included 'short dental implants', 'posterior edentulism', 'survival rates', 'marginal bone loss', 'peri-implantitis', and 'bone augmentation'. Randomized controlled trials (RCTs), systematic reviews, meta-analyses, and prospective and retrospective clinical studies published between 2018 and 2024 were included. Studies were selected based on implant intrabony length of ≤6 mm, a minimum follow-up of 12 months, and reporting of at least one primary outcome. Results: Evidence from a meta-analysis of 16 RCTs (408 short implants; 475 standard-length implants) demonstrates statistically higher survival rates for longer implants (99.4% vs. 95.1%; 95% CI: 2–5%, p < 0.001), though no significant difference was found in early or late implant failure rates. MBL was marginally but non-significantly lower for short implants (0.23 mm vs. 0.27 mm). Peri-implantitis prevalence (0–6% vs. 0–13%) and technical/prosthetic complication rates were comparable between groups. Crown-to-implant ratios of 1.55–1.86 in short implants did not translate to elevated complication rates when prostheses were splinted. A systematic review and meta-analysis of 13 RCTs confirmed equivalent survival at all follow-up intervals without the need for bone augmentation. Conclusions: Short dental implants represent a valid, minimally invasive alternative to bone augmentation in appropriately selected patients. Optimal outcomes depend on modern nano-structured implant surfaces, adequate prosthetic splinting, bone quality assessment, and rigorous peri-implant maintenance. Further long-term RCTs with standardized peri-implantitis criteria are needed.