Impact of periodontal treatment on systemic health

Background + Aims

• Periodontitis is associated with systemic inflammation and has been linked to chronic kidney disease (CKD) and diabetes mellitus (DM).
• Periodontal inflammation may contribute to impaired kidney function through the spread of bacterial products and inflammatory mediators. However, previous research has largely been observational, with inconsistent findings.
• Evidence from randomised controlled trials investigating whether periodontal treatment improves kidney function remains limited.
• This study aimed to:
  • Evaluate the effect of non-surgical periodontal therapy (NSPT) on renal function in patients with CKD and periodontitis.
  • Assess its effect on systemic inflammation and, in participants with diabetes, glycaemic control.

Materials + Methods

• This single-centre randomised controlled trial in Athens, Greece, evaluated patients with CKD stages II–IV and periodontitis over 6-months.
• 60 participants were randomised
  • 53 were included in the reported analysis, including 32 with diabetes.
• The intervention group received non-surgical periodontal therapy and supportive care.
• Controls received baseline oral hygiene advice and supragingival cleaning, with definitive treatment offered after the study.
• Assessments were conducted at baseline and 1-, 3-, and 6-months:
• Primary outcome: estimated glomerular filtration rate (eGFR) calculated using creatinine alone and creatinine with cystatin-C.
• Additional outcomes: urine albumin to urine creatinine ratio (uACR), serum high-sensitivity C-reactive protein (hsCRP) levels, glycated haemoglobin (HbA1c) in participants with diabetes, and periodontal measures.
• The periodontal examiner was blinded to allocation. Analyses adjusted for baseline values and multiple comparisons where applicable.

Results

• Periodontal health: Treatment improved periodontal measures, with bleeding on probing decreasing by 40.6 percentage points versus 6.2 percentage points in controls at 6-months.
• Kidney function: Adjusted eGFR was approximately 10.3–11.2 mL/min/1.73 m² higher in the treatment group than controls, depending on the equation used (both p<0.001).
• Glycaemic control: Among participants with diabetes, adjusted HbA1c was 0.54 percentage points lower in the treatment group at 6-months (95% CI: −0.85 to −0.23; adjusted p=0.003).
• Systemic inflammation: Adjusted hsCRP was lower with treatment: 1.19 versus 2.19 mg/L at six months.
• Albuminuria: uACR favoured treatment, but the difference was not statistically significant after correction for multiple comparisons (p=0.10).

Limitations

• Only 53 participants were analysed, including 32 with diabetes, limiting statistical precision and subgroup analyses.
• A single-centre setting and 6-month follow-up limit conclusions about other populations and long-term kidney outcomes.
• Urine analyser limitations excluded 20 participants from the uACR analysis.
• Complex medical conditions, multiple medications and insulin-dose adjustments complicated interpretation.
• Seven of the 60 randomised participants were excluded before the reported analysis. Later missing observations were handled by carrying the last measurement forward, which does not eliminate attrition bias.
• No formal pre-study sample-size calculation was performed, and participants could not be blinded.
• Treatment improved periodontal health but did not necessarily achieve full disease control in all participants.

Conclusion

• Overall, the findings suggest that NSPT with supportive care may improve kidney filtration estimates, reduce systemic inflammation and improve glycaemic control in patients with CKD and periodontitis.
• These results support collaboration between dental, renal and diabetes teams, but larger trials with longer follow-up are needed before periodontal treatment can be considered a proven strategy for preventing CKD progression.