Effect of Magnesium-Modified Titanium Implants on Osseointegration: A Systematic Review and Meta-Analysis of Preclinical Studies

<b>Objectives</b>: This study systematically evaluated and quantitatively synthesized preclinical evidence on the effects of magnesium (Mg) incorporation into or coating of titanium dental implants on osseointegration and peri-implant bone formation. <b>Methods</b>: Electronic searches of PubMed, Scopus, and Web of Science were performed up to May 2025 to identify animal studies evaluating Mg-modified titanium implants. Eligible studies compared Mg-incorporated or Mg-coated implants with non-modified titanium controls and reported quantitative histomorphometric outcomes. Primary outcomes included the values of bone-to-implant contact (BIC) and bone area (BA) around implants. Study quality was assessed using the ARRIVE 2.0 guidelines. Meta-analyses were performed using weighted mean differences with 95% confidence intervals under fixed- or random-effects models based on heterogeneity. <b>Results</b>: Eleven preclinical animal studies conducted in rabbit and rat models were included. Mg was incorporated using various surface-modification techniques, including ion implantation, Mg-substituted hydroxyapatite coatings, mesoporous titania layers, and nanotubular structures. Overall, the studies' quality was high, with most studies rated as excellent and with a low-to-moderate risk of bias. Furthermore, the meta-analysis revealed a significant increase in BIC for Mg-modified implants compared with uncoated implants (Z = 4.38, <i>p</i> < 0.001), implying improved osseointegration. Meanwhile, pooled BA values showed no significant differences between the groups (Z = 0.93, <i>p</i> = 0.35). <b>Conclusions</b>: Mg coating onto or incorporation into titanium implant surfaces can improve BIC in preclinical models, indicating improved osseointegration in the early stages.