Clinical question: How do titanium dental implants perform over the very long term? Most evidence stops at five or ten years. This systematic review and meta-analysis pushed the horizon to twenty.

Methodology: The authors restricted inclusion to prospective studies only — the most reliable design for survival data — and to cylindrical or conical screw-shaped titanium implants. Ten studies qualified, covering 1,857 implants at baseline; 1,028 of these were followed for at least 20 years. Survival was estimated with a Kaplan-Meier approach that accounted for censored observations, while marginal bone loss (MBL) was pooled with a random-effects meta-analysis. Certainty of evidence was graded with GRADE.

Main findings: Over 20 years, 115 implants failed. The pooled survival rate was 93.0% (95% CI 91.6-94.1%). Where the cause of failure was reported (44 cases), biological and mechanical causes were almost evenly split. Pooled mean MBL was modest — 1.11 mm (95% CI 0.55-1.68 mm) — but the variability was striking: across studies, marginal bone ranged from slight gain to moderate loss. An exploratory subgroup analysis hinted that implant surface characteristics may influence MBL, though the small number of implants and high heterogeneity demand caution. GRADE certainty was moderate for both survival and MBL.

Clinical relevance: A 93% survival rate after two decades is a reassuring number to share with patients weighing implant therapy. It confirms that a well-placed titanium implant is a durable solution, not a provisional one. Two caveats temper the optimism. First, failures are not concentrated on the biological side — mechanical complications matter just as much over the long run, which argues for attention to prosthetic design and occlusal load, not only peri-implant health. Second, the wide spread in marginal bone behaviour reminds clinicians that "average" stability hides individual trajectories; surface type, maintenance and host factors all play a part. The authors call for more well-designed long-term studies, and the heterogeneity here justifies that request. For now the message to the implantologist is grounded: longevity is realistic, but it is earned through case selection, prosthetic precision and long-term maintenance.