Immediate vs. Delayed Loading of Dental Implants in the Posterior Maxilla: A Systematic Review and Meta-Analysis

Abstract Background: Immediate loading of dental implants offers advantages such as reduced treatment time and earlier function. However, in the posterior maxilla—characterized by low bone density—concerns remain about implant survival and marginal bone loss (MBL). Objective: To compare implant survival rates and marginal bone loss between immediate and delayed loading protocols in the posterior maxilla. Methods: A systematic search was conducted in PubMed, Embase, Cochrane CENTRAL, Scopus, and Web of Science for studies published between 2010 and April 2025. Randomized controlled trials and cohort studies comparing immediate (within 72 hours) and delayed (≥3 months) loading of implants in the posterior maxilla were included. Primary outcomes were implant survival and MBL. Risk of bias was assessed using the Cochrane RoB 2 tool for RCTs and the Newcastle-Ottawa Scale for cohort studies. Meta-analysis was performed using RevMan. Results: Five studies (3 RCTs, 2 cohort studies) with 6–36 months of follow-up were included. Implant survival rates were comparable between immediate (95.5–100%) and delayed loading (96.0–100%) with no significant difference (RR = 0.98 [0.95, 1.01], p = 0.18; I² = 12%). MBL was slightly higher in the immediate loading group (+0.22 mm [0.08, 0.36], p = 0.004; I² = 26%) but remained within clinically acceptable limits (<0.5 mm). Conclusion: Immediate loading in the posterior maxilla shows similar implant survival to delayed loading, with a modest increase in MBL that remains clinically acceptable. When primary stability and case selection are adequate, immediate loading can be a predictable treatment option offering reduced treatment time and improved patient satisfaction.