Impact of Age-Related Bone Density Variations on Dental Implant Stability and Success Rates: A Retrospective Analysis

Dental implant success depends on factors such as age and bone density; this study evaluates how age-related bone density changes affect implant stability and survival.

This retrospective cohort study included patients receiving dental implants at the Affiliated Stomatological Hospital of Chongqing Medical University (March 2019-2024). Peri-implant bone density was measured by cone-beam computed tomography (CBCT) in Hounsfield units (HU) at coronal and apical sites 1, 2, 3, and 6 months postoperatively. The primary outcome was implant stability, assessed with resonance frequency analysis (RFA). Secondary outcome was early implant failure within 6 months. Implant success required stability without mobility or infection. Quality of life was the tertiary outcome, measured using the Oral Health Impact Profile-14 (OHIP-14).

A total of 1,621 subjects with 1,821 implants were analyzed. Older adults (66-80 years) demonstrated lower bone density and stability, with markedly higher early failure (14.56%) and infection rates (22.78%, both P < .001), compared with younger groups (failure rate: 4.99% in 20-35 years; 1.07% in 36-50 years; 0.64% in 51-65 years). At 6 months, cumulative implant survival declined to 85.4% in the 66-80 years group versus >95% in younger groups. Logistic regression further identified age (OR = 0.481, P = .014) and low bone density (OR = 1.89, P = .019) as significant risk factors for early implant failure. The model showed good discrimination (AUC = 0.823) and acceptable fit (Nagelkerke R² = 0.21), supporting the robustness of these estimates.

Age-related bone loss may impair implant success. Older adults showed higher early failure risks, while younger patients experienced greater QoL gains, suggesting a need for age-specific, personalized implant strategies.