Comparative Clinical Outcomes of Mini Implants Retained Mandibular Overdenture vs. Standard Diameter Implants: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Abstract

Background: Mini dental implants (MDIs) have emerged as a promising solution for retaining mandibular overdentures, particularly when standard-diameter implants (SDIs) are not viable due to anatomical limitations. Despite their increasing use, a comprehensive evaluation of their effectiveness, patient satisfaction, and prosthetic complications compared to SDIs is essential. Objective: This systematic review and meta-analysis aimed to evaluate the survival rates, patient satisfaction, and complications associated with MDIs in comparison to SDIs for retaining mandibular overdentures. Methods: A systematic search across five electronic databases and handsearching identified 576 records. Statistical analyses were conducted using mean differences (MD) and risk ratios (RR) to assess continuous and dichotomous outcomes, including survival rate, patient satisfaction, prosthetic complications, and peri-implant marginal bone loss. Subgroup analyses explored the impact of the number and distribution of implants on these outcomes. Results: With eight randomised controlled trials meeting the inclusion criteria, the analysis revealed no statistically significant difference in survival rates between MDIs and SDIs. However, MDIs demonstrated superior patient satisfaction scores (MD:9.12,95%CI:6.51– 11.74,p<0.00001) and statistically significant result of 2MDI vs 2SDI peri-implant marginal bone loss (MD:-0.92,95%CI [-1.15, -0.70],p<0.00001). Additionally, the results implied that prosthetic complications had lower frequency for intervention compare to control group. Conclusion: MDIs represent a viable alternative to SDIs for retaining mandibular overdentures, offering comparable survival rates and improved patient satisfaction. Their use is particularly advantageous in patients with limited alveolar bone. However, further long- term research is warranted to confirm these findings and refine clinical guidelines for implant selection.