Use of adjuncts in periodontal treatment for patients with diabetes

Background + Aims

• Studies have shown that initial periodontal therapy, such as scaling and root planing (SRP), either alone or combined with adjunctive treatments like antimicrobials, can improve clinical outcomes in both diabetic and non-diabetic individuals.
• These benefits are thought to arise from reducing pathogenic bacteria and establishing a microbiota conducive to periodontal health.
• Maintenance programs, including repeated SRP, can help sustain these improvements, although persistent deep pockets, angular defects, and furcation involvements may not respond well to SRP alone. In such cases, surgical approaches or systemic antimicrobials have been proposed to enhance treatment outcomes, especially for unresponsive sites.
• Surgical methods like access flap techniques have demonstrated better reductions in probing pocket depth (PPD) and clinical attachment level (CAL) gains compared to non-surgical treatments.
• While protocols for unresponsive pockets in non-diabetic individuals exist, data on type 2 diabetes patients remain scarce.
• This pilot study evaluates surgical and non-surgical debridement, with systemic metronidazole and amoxicillin, for treating residual pockets in type 2 diabetics using a split-mouth design.

Materials + Methods

• This prospective, split-mouth, randomised controlled clinical study (RCT) involved 21 type 2 diabetic patients (aged 42–67) with generalised chronic periodontitis and residual pockets.
• Inclusion criteria included:
  • Diagnosis of type 2 diabetes for ≥6 years
  • Age >40
  • ≥15 teeth
  • ≥30% sites with PPD and CAL ≥4 mm
• Exclusion criteria included:
  • Pregnancy
  • Recent smoking history
  • Antimicrobial use
  • Systemic conditions other than diabetes.
• All subjects underwent initial SRP without antimicrobials and were enrolled in supportive periodontal therapy.
• After 12 months, 21 patients with at least two non-adjacent residual pockets per half-contralateral quadrant were included.
Residual pockets were defined as sites with PPD ≥5 mm and BOP requiring additional treatment.
• 
Quadrants were randomly assigned via a computer-generated table to surgical or non-surgical debridement. Surgical debridement involved sulcular incisions, full-thickness flap elevation, granulation tissue removal, and meticulous SRP, followed by flap repositioning and suturing. Non-surgical debridement consisted of SRP without flap elevation.
• Each participant received both treatments on opposite sides of the mouth. Surgery was performed first, followed by non-surgical debridement six days later. All participants received one shared course of metronidazole (400 mg) plus amoxicillin (500 mg), each three times daily for 10 days, starting on the surgery day.
• Chlorhexidine 0.12% mouthwash was prescribed twice daily for two weeks from surgery, leaving eight days of rinsing after non-surgical treatment. Standardised toothpaste was provided and medication adherence monitored.
• 
Clinical parameters, including PPD, CAL, plaque index, BOP, and marginal bleeding, were assessed at baseline, 3, and 6 months.
• Gingival crevicular fluid (GCF) was sampled from residual pockets for cytokine analysis using ELISA.
• The primary outcome was the change in probing depth at residual pockets. Analyses distinguished residual pockets from quadrant measurements, which also included neighbouring teeth. Paired comparisons accounted for the split-mouth design; significance was set at p < 0.05. HbA1c was measured only at baseline.

Results

• All 21 participants completed follow-up (13 men and eight women; mean age 53.2 ± 9.1 years). Baseline mean HbA1c was 11.3 ± 2.3%, and mean diabetes duration was 7.1 ± 0.9 years.
• Six participants reported one or two medication-related adverse effects, including diarrhoea, vomiting, headache, metallic taste or irritability.
• Both treatments significantly improved residual-pocket probing depths, attachment levels and counts. No significant between-treatment differences were found for these residual-pocket outcomes. At six months, mean probing-depth reductions were 2.1 mm after surgery and 1.7 mm after non-surgical treatment.
• At quadrant level, which included treated teeth and neighbouring teeth, surgery produced greater probing-depth reduction at six months (0.9 versus 0.4 mm; p < 0.05). Only surgical quadrants showed significant attachment improvement from baseline, but this did not establish a significant attachment advantage over non-surgical treatment.
• Surgical quadrants started with approximately 0.5 mm greater mean probing depth and attachment loss. The authors noted that these baseline differences could partly explain the greater quadrant-level improvement.
• At six months, GCF concentrations of IFN-γ, IL-4, IL-17 and IL-23 were higher at surgically treated sites than at non-surgically treated sites (p < 0.05). In contrast, the sampled sites showed no significant between-treatment differences in probing depth, attachment level or GCF volume.
• The authors proposed prolonged wound healing after surgery as a possible explanation for the cytokine findings. This mechanism was not directly demonstrated, and the clinical significance of the higher cytokine concentrations remains uncertain.

Limitations

• Treatment order and adjunct timing differed: non-surgical treatment occurred six days after surgery, leaving four days of the shared antibiotic course and eight days of chlorhexidine rinsing after non-surgical treatment. These were not separate medication courses or patient groups.
• The examiner could identify which quadrants underwent which treatment based on visible surgical changes, and patients could also distinguish between the treatments. This lack of blinding introduces potential bias in clinical and subjective assessments.
• The study did not include a non-diabetic control group, limiting the ability to evaluate whether the heightened cytokine levels post-surgical debridement were specific to the diabetic population or reflective of a general delayed wound healing and inflammation process.
• The small pilot study and six-month follow-up limit conclusions about long-term outcomes. Absence of a statistically significant difference does not establish treatment equivalence. There was no antibiotic-free comparison, and baseline-only HbA1c measurements preclude assessment of glycaemic improvement.

Conclusion

• Both approaches, combined with the shared antimicrobial regimen, improved residual pockets over six months. Surgery did not demonstrate superior clinical outcomes for the residual pockets themselves, although it produced greater quadrant-level probing-depth reduction and higher local cytokine concentrations.
• The small pilot study does not establish treatment equivalence, isolate the added benefit of antibiotics or explain the biological significance of the cytokine differences.