Immediate implants in diabetics survive — but bone pays the price of glycemic control

As dental implants become routine even in medically complex patients, clinicians increasingly face the question of whether immediate implant placement (IIP) — inserting the implant at the same appointment as tooth extraction — is safe in patients with diabetes. Prior evidence on this specific combination has been fragmented. This systematic review and meta-analysis searched PubMed, Embase, Web of Science, Cochrane, Google Scholar and CNKI (January 2000–March 2025) for studies comparing implant survival rate (SR), marginal bone loss (MBL), probing depth (PD) and bleeding on probing (BOP) between diabetic (well- and poorly-controlled) and healthy patients undergoing IIP.

Ten studies met inclusion criteria, covering 1,350 patients and 1,623 implants, with moderate-to-high overall methodological quality (Newcastle-Ottawa Scale). The headline finding: implant survival was not significantly different between diabetics and healthy controls, regardless of glycemic control — well-controlled diabetics showed RR 1.00 (95% CI 0.97–1.02) and even poorly-controlled diabetics showed RR 0.96 (95% CI 0.88–1.06) versus healthy patients.

However, survival is not the whole picture. Marginal bone loss was significantly higher in diabetics than in healthy patients, and — critically — the magnitude scaled with glycemic control: well-controlled diabetics showed a modest but significant MBL increase (MD 0.08 mm), while poorly-controlled diabetics showed a much larger increase (MD 0.39 mm). A similar gradient appeared for inflammatory markers: well-controlled diabetics had significantly higher BOP than healthy patients but comparable probing depth, while poorly-controlled diabetics showed significantly higher values for both BOP (MD 0.24) and PD (MD 0.62).

The clinical message is nuanced rather than reassuring-or-alarming: IIP is feasible in diabetic patients, including as an evidence-based option rather than a contraindication, but glycemic control is the variable that determines how much peri-implant bone and soft-tissue health is traded away. For well-controlled patients, the added risk is small; for poorly-controlled patients, it is substantial enough to warrant either deferring implant placement until control improves or intensifying postoperative monitoring. The authors flag notable heterogeneity as a limitation, but the consistency of the dose-response pattern strengthens confidence in the underlying biological relationship.