Association between peri-implantitis and diabetes

Background + Aims

• Diabetes is a well-established risk factor for periodontitis. Dental implants are a common treatment after tooth loss, but roughly 1 in 5 patients eventually develop peri-implantitis, which can lead to further bone loss and, ultimately, loss of the implant.
• Whether diabetes also increases the risk of peri-implantitis has been debated. Earlier studies were small, often did not distinguish between Type 1 diabetes mellitus (T1DM) and Type 2 diabetes mellitus (T2DM), and produced conflicting results. Very little was known specifically about T1DM.
• This study aimed to:
  • Evaluate the association between diabetes (both T1DM and T2DM) and peri-implantitis using nationwide Swedish health and dental registers.

Materials + Methods

• Register-based cohort study using 3 Swedish nationwide registers: the National Diabetes Register, the Swedish Quality Registry for Caries and Periodontal disease (SKaPa) and the Total Population Register.
• Follow-up period: 2010–2020.
• 4 Four groups of adults with dental implants were identified
  • With T1DM
  • Without T1DM
  • With T2DM
  • Without T2DM
• Peri-implantitis was primarily defined by recorded treatment codes (non-surgical treatment, surgical treatment or implant removal linked to a peri-implantitis diagnosis). A sensitivity definition (an alternative definition used to test whether results still hold) based on a probing depth ≥6 mm (how deep the periodontal probe reaches around the implant) was also examined.
• Glycaemic control was categorised from repeated HbA1c measurements: good control (HbA1c <52 mmol/mol at least 75% of the time) versus poor control (HbA1c >62 mmol/mol at least 75% of the time).
• 2 analyses were run:
  • Prevalence (existing cases): 18,975 individuals, using logistic regression adjusted for age, gender, education, income and number of implants; results expressed as odds ratios (OR — how much more likely the outcome is in one group compared with another).
  • Incidence (new cases developing over time): 2,030 individuals, using flexible parametric survival analysis after propensity-score matching (a statistical technique that pairs people with and without diabetes who have similar characteristics, to mimic a fairer comparison). Results expressed as hazard ratios (HR — how much faster new cases develop in one group compared with another).
• All analyses were repeated with additional adjustment for periodontitis.

Results

• Prevalence of peri-implantitis
  • T1DM vs. non-T1DM 21.1% vs. 15.2%; OR 1.46 (95% CI 1.05–2.04) – a statistically significant increase.
  • T2DM vs. non-T2DM: 20.5% vs. 18.2%; OR 1.06 (95% CI 0.98–1.16) – no significant difference.
• Prevalence of implant loss due to peri-implantitis
  • T1DM: OR 2.39 (95% CI 1.10–5.20) – significantly higher.
  • T2DM: OR 1.33 (95% CI 1.06–1.66) – significantly higher.
• Incidence of peri-implantitis (new cases during follow-up)
  • T1DM: HR 1.52 (95% CI 0.96–2.42) – a trend towards higher risk, not statistically significant.
  • T2DM: HR 1.36 (95% CI 1.02–1.82) – statistically significant.
• Incidence of implant loss
  • T1DM: HR 3.11 (95% CI 0.84–11.49) – a suggestive but non-significant trend, with wide uncertainty.
  • T2DM: HR 0.88 (95% CI 0.39–1.95) – no clear difference.
• Effect of adjusting for periodontitis
  • Estimates were largely unchanged, indicating that the diabetes–peri-implantitis link is not simply explained by co-existing gum disease.
  • Periodontitis itself remained a strong independent risk factor for peri-implantitis (OR 2.54 in the T1DM cohort; OR 3.67 in the T2DM cohort).
• Glycaemic control
  • T1DM with poor control:
    • Peri-implantitis prevalence: 31.7%; OR 2.46 (95% CI 1.52–4.00) vs. non-T1DM.
    • Implant loss: OR 4.24 (95% CI 1.61–11.19).
  • T1DM with good control
    • Peri-implantitis prevalence only 5.6%; no significant increase.
  • T2DM:
    • No significant difference in peri-implantitis prevalence by control category
    • Implant loss was more frequent under poor control (OR 1.84, 95% CI 1.04–3.27).
• Sensitivity analysis
  • Defining peri-implantitis by probing depth (≥6 mm) rather than treatment codes produced broadly similar estimates.

Limitations