Impact of obesity on dental implant failure and peri-implant health: a systematic review and meta-analysis

Obesity is a growing epidemic worldwide; however, its impact on dental implant outcomes remains unclear. We systematically reviewed the evidence of the effects of body mass index (BMI) on the risk of implant failure and peri-implant health indices. PubMed, Embase, Scopus, and Web of Science literature databases were searched for studies assessing the impact of BMI on dental implant failure and peri-implant health indices up to June 10, 2025. Implant failure was the primary outcome, while plaque index, bleeding on probing (BOP), probing depth, and marginal bone loss (MBL) were secondary outcomes. The quality of the studies was assessed using the Newcastle-Ottawa Scale for cohort studies and the JBI Critical Appraisal Checklist for Cross-Sectional Studies. Odds ratios (OR) with 95% confidence intervals (CI) were calculated for dichotomous data. Mean difference (MD) or Standardised MD (SMD) were generated for continuous variables. Eleven studies were included in the review, and nine were available for the meta-analysis. Meta-analysis showed that there was no statistically significant difference in the risk of implant failure between obese and non-obese groups (OR: 0.73 95% CI: 0.29, 1.86 I2 = 67%). However, pooled analysis showed that obese patients had significantly higher plaque index values (SMD: 2.24 95% CI: 0.84, 3.64 I2 = 95%), higher probing depth (MD: 1.56 95% CI: 1.32, 1.80 I2 = 95%), higher BOP rates, (SMD: 2.89 95% CI: 1.25, 4.53 I2 = 97%) and greater MBL (MD: 1.20 95% CI: 0.67, 1.72 I2 = 99%) as compared to non-obese patients. Sensitivity analyses confirmed the consistency of the results. Certainty of evidence was ‘very low’ for all outcomes. Low-quality evidence from a limited number of predominantly retrospective studies suggests that obesity may not significantly affect implant failure rates. However, it is associated with worse peri-implant health indices. Further high-quality, prospective studies are necessary to strengthen the evidence base.