Survival rates of immediately loaded single implants compared to early / conventionally loaded: An overview of systematic reviews

Title: Survival rates of immediately loaded single implants compared to early/conventionally loaded: An overview of systematic reviews. Background: Immediate loading of single dental implants has become increasingly popular due to the demand for function and esthetics within shorter treatment times. However, concerns persist regarding its long-term predictability compared with early or conventional loading. This overview of systematic reviews, complemented by a de novo meta-analysis of randomized controlled trials (RCTs), aimed to evaluate implant survival, marginal bone loss (MBL), complications and patient satisfaction between loading protocols. Methods: A comprehensive search of PubMed, Embase, Scopus, Epistemonikos and the Cochrane Database was conducted up to October 2025. Systematic reviews including only RCTs comparing immediate versus early/conventional loading in single-tooth implants were eligible. Primary studies were re-extracted to prevent data overlap and quantitative synthesis was performed in R using random-effects meta-analysis. Overlap was quantified with the Corrected Covered Area (CCA). Methodological quality was assessed via AMSTAR-2 and certainty of evidence via GRADE. Results: Seven systematic reviews and two additional RCTs (40 unique trials; >1,200 implants; follow-up 1–10 years) were included. Evidence overlap was high (CCA=11.5%). Pooled analyses showed no significant difference in implant survival at 1 year between immediate and conventional loading (n=13; RR=1.00; 95%CI: 0.98–1.02; I2=0%) and between immediate and early loading (n=3; RR=0.99; 95% CI: 0.961–1.02; I2=0%), at 2 years immediate versus conventional (n=3; RR=1.01; 95%CI: 0.96 – 1.05; I2=0%), and immediate versus early/conventional at 3 years (n=3; RR=1.01; 95%CI: 0.97–1.05; I2=0%), or 5 years (n=5; RR=1.00; 95%:CI 0.97–1.03; I2=0%). MBL was minimal and clinically negligible (1-year immediate versus conventional: n=12, MD≈0.00 mm, 95%CI: −0.1 to 0.08, I2=56%; immediate versus early/conventional 3-year: n=3, MD=0.06 mm, 95%CI: −0.50 to 0.62, I2=50.1% and 5-year: MD=−0.07 mm, 95% CI: −0.42 to 0.28, I2=91%). Patient satisfaction did not differ between immediate and conventional loading (n=3, SMD=−0.20, 95%CI: −1.90 to 1.50, I2=79.3% 1-year; n=2, SMD=0.03, 95%CI: −3.43 to 3.48, I2=37.9% 5-year) and prosthetic/biological complications were rare. Certainty was moderate for survival, low for MBL and complications and very low for patient satisfaction. Funnel plot and Egger’s test suggested no publication bias. Conclusion: Immediate loading of single implants yields survival, marginal bone stability and patient satisfaction similar to early/conventional loading when applied under proper clinical conditions.