Comparing short dental implant and standard dental implant in terms of marginal bone level changes: A systematic review and meta-analysis of randomized controlled trials

Purpose To compare short implants (SH; 4-8 mm) to standard implants (ST; longer than 8 mm) in edentulous jaws, evaluating pri-implant marginal bone levels (MBLs) changes, implant failures (IFs), complications, and prosthesis failures (PFs). Materials and Methods Electronic searches were conducted through the PubMed, Web of Science, EMBASE, Scopus, the Cochrane Central Register of Controlled Trials, and to locate all randomized controlled trials (RCTs) comparing SH to ST. Meta-analysis procedures were performed on the weighted mean difference (WMD) and standardized mean difference (SMD) of MBLs using Stata. Results Twenty-three articles were included in this review. The WMD of MBLs when comparing SH to ST in both jaws up to 1-year follow-up was statistically significant preferring SH (WMD: -0.09 [CI: -0.12, -0.06], I-2: 67.0%). The efficacy of SH vs ST on SMD of MBLs was moderate (SMD: -0.43 [CI: -0.57, -0.28], I-2: 55.7%). There were no significant differences in IF (RR: 0.75 [0.44,1.27]) and PF (RR: 0.58 (0.22,1.581), and significantly higher biological complications (RR: 0.25 [0.15, 0.40]) for SH was observed compared to the ST in both jaws up to 1-year follow-up. Conclusions SH and ST implants showed the comparable outcomes except biological complication preferring SH. Future systematic review and meta-analysis with longer and larger RCTs are required to confirm the present outcomes.