Impact of periodontal treatment on systemic health

Background + Aims

• Periodontitis, a chronic inflammatory condition affecting tooth-supporting structures, is increasingly recognised as influencing systemic health. Evidence links periodontitis with cardiovascular disease (CVD), atherosclerosis, and metabolic disorders, such as diabetes. The disease’s systemic effects may stem from persistent low-grade inflammation and the spread of oral bacteria and pro-inflammatory cytokines into circulation. Elevated markers like high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) are shared by periodontitis and atherosclerosis.
• Although individual studies suggest periodontal therapy reduces systemic inflammation and improves endothelial function, heterogeneity across trials has led to inconclusive results.
• This systematic review and meta-analysis aimed to synthesise robust evidence on whether treating periodontitis improves biomarkers of atherosclerosis and systemic inflammation, focusing on patients with or without comorbidities such as CVD or diabetes. Improved understanding of this link is vital for clinicians to integrate dental health into broader management of systemic diseases.

• The study aims to assess whether periodontal therapy reduces systemic inflammation, improves lipid and glucose metabolism, and enhances vascular function in patients with periodontitis, with or without comorbidities such as CVD or diabetes, by evaluating changes in biomarkers like hsCRP, IL-6, and HbA1c.

Materials + Methods

• The systematic review and meta-analysis synthesised data from clinical intervention trials on the effects of periodontal therapy.
• Literature was searched up to June 2013 using three databases: Medline-PubMed, Cochrane CENTRAL, and EMBASE. The search was designed to identify studies examining the impact of periodontal therapy on cardiovascular disease (CVD) parameters or markers of systemic inflammation, lipid and glucose metabolism, and vascular function.
• Eligibility criteria:
  • Only randomised controlled trials (RCTs) or controlled clinical trials (CCTs) involving human subjects were included.
  • Studies must have a treatment group receiving periodontal therapy and a control group receiving no periodontal treatment.
  • Reported outcomes included cardiovascular events (angina pectoris, myocardial infarction, stroke, death) and/or markers related to atherosclerosis and CVD risk, such as markers of systemic inflammation and thrombosis, lipid and glucose metabolism and vascular function.
  • Studies without a proper non-treatment control group or focusing on other conditions (e.g., pregnancy outcomes) were excluded.
• Initial screening of 3,928 titles and abstracts identified 491 studies for full-text review. After applying eligibility criteria, 25 trials from 20 publications with 1,748 participants were included.
• Two independent reviewers extracted data on biomarkers, treatment methods, and outcomes. Methodological quality was assessed based on randomisation, blinding, follow-up, and other risk-of-bias criteria.
• Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated for markers using random-effects models. Subgroup analyses were performed for populations with comorbidities, smokers versus non-smokers, and varying BMI levels.

Results

• None of the included trials used a cardiovascular event as the outcome parameter.
• Inflammatory Markers:
  • Periodontal therapy significantly reduced hsCRP levels by an average of 0.50 mg/L, with the reduction being larger in patients with comorbidities, such as CVD or diabetes, at 0.71 mg/L. Non-smokers experienced a reduction of 0.56 mg/L, while smokers showed minimal changes.
  • IL-6 levels decreased by 0.48 ng/L, with the greatest reductions observed in patients with comorbidities (0.87 ng/L).
  • TNF-α decreased by 0.75 pg/mL, and fibrinogen levels dropped by 0.47 g/L, highlighting a significant reduction in inflammatory and thrombotic markers.
• Lipid and Glucose Metabolism:
  • HbA1c levels dropped by 0.43% in patients with diabetes after periodontal therapy, demonstrating improved glycaemic control.
  • Total cholesterol levels were reduced by 0.11 mmol/L, and HDL-C levels improved by 0.04 mmol/L. Triglycerides decreased by 0.24 mmol/L, particularly in patients with systemic conditions.
  • No significant changes were observed in lipid or glucose markers in otherwise healthy participants without comorbidities.
• Vascular Function:
  • Improvements in endothelial function, assessed through measures such as flow-mediated dilation, were reported in five trials. Other vascular function markers, including systolic and diastolic blood pressure, remained largely unchanged.
• Subgroup Analysis:
  • Patients with a follow-up period of less than six months experienced greater reductions in hsCRP (0.89 mg/L) compared to those with longer follow-up durations (0.24 mg/L).
  • Overweight individuals and smokers showed less pronounced improvements than their normal-weight and non-smoking counterparts.
• Most studies consistently highlighted periodontal therapy’s substantial benefits in reducing inflammation and improving metabolic markers, particularly in patients with underlying systemic diseases.

Limitations

• None of the included trials assessed hard clinical outcomes, such as heart attacks or strokes, relying instead on biomarkers, which may not fully reflect long-term cardiovascular benefits.
• The heterogeneity in study designs, populations, and follow-up durations introduced variability, making direct comparisons challenging.
• Many studies included adjunctive treatments, such as antibiotics, which could confound the effects attributed to periodontal therapy alone.
• The focus on patients with comorbidities limits the generalisability to healthy populations.
• Publication bias and methodological variability, including inconsistent blinding and randomisation, may affect the validity of findings.
• The absence of standardised periodontal treatment protocols and varying severities of periodontitis among participants further complicated the interpretation of results.

Conclusion

• The findings highlight that periodontal therapy provides significant systemic health benefits, particularly for patients with comorbidities such as cardiovascular disease (CVD) or diabetes. Treatment effectively reduces systemic inflammation (e.g., hsCRP, IL-6, TNF-α), improves glycaemic control (HbA1c reduction), and enhances lipid profiles (increased HDL-C and reduced total cholesterol and triglycerides). These benefits are most pronounced in individuals with coexisting systemic conditions, underscoring the interconnected nature of periodontal and systemic health.

• Integrating periodontal care into management protocols for CVD and diabetes can enhance systemic health, highlighting the need for collaboration between dentists, doctors, and cardiologists. 

• Future research should focus on long-term, large-scale trials to confirm whether periodontal therapy reduces clinical risks, including heart attacks and strokes, beyond improving surrogate biomarkers.