Metformin Versus Chlorhexidine Gel as Adjuncts to Scaling and Root Planing in Stage II Grade B Periodontitis

Comparative Study Between Metformin and Chlorhexidine Gel as Adjunctive to Conventional Non-Surgical Treatment of Stage II Grade B Periodontitis: A Randomized Controlled Clinical Trial

This clinical trial is designed to evaluate two locally delivered gels, metformin and chlorhexidine, as adjunctive therapies to scaling and root planing (SRP) in patients with Stage II, Grade B periodontitis. Periodontitis is a chronic inflammatory condition that damages the supporting tissues of the teeth. Although SRP is the standard non-surgical treatment, it may not fully eliminate harmful bacteria or prevent disease recurrence.

Chlorhexidine is a widely used antimicrobial gel, while metformin, a medication commonly prescribed for diabetes, has shown anti-inflammatory and bone-supportive effects when used locally in the gums. This study will directly compare the effectiveness of 1% metformin gel and 0.2% chlorhexidine gel, both applied subgingivally after SRP, against SRP alone.

Sixty adult participants diagnosed with Stage II, Grade B periodontitis will be randomly assigned into three groups: SRP only (control), SRP plus metformin gel, and SRP plus chlorhexidine gel. Clinical outcomes (plaque index, gingival index, probing pocket depth, and clinical attachment level), inflammatory markers (MMP-8 in gingival crevicular fluid), and radiographic bone density will be measured at baseline, 1 month, 3 months, and 6 months.

The goal is to determine whether metformin gel or chlorhexidine gel provides superior improvements in periodontal healing when compared with SRP alone. Findings from this trial may guide evidence-based decisions on optimizing non-surgical periodontal therapy.

This is a randomized, controlled, single-blind clinical trial conducted at the Department of Oral Medicine, Periodontology, Oral Diagnosis, and Oral Radiology, Faculty of Dentistry, Kafrelsheikh University, Egypt. Sixty participants aged 18-60 years with Stage II, Grade B periodontitis will be enrolled. Participants will be randomly allocated (1:1:1) into three groups:

Group A (Control): SRP only

Group B (Test 1): SRP + 1% Metformin Gel

Group C (Test 2): SRP + 0.2% Chlorhexidine Gel

Subgingival gels will be applied after SRP using sterile syringes, followed by periodontal pack placement for one week. All patients will receive standardized oral hygiene instructions.

Outcome Measures:

Primary Outcomes: Clinical attachment level (CAL) changes, reduction in inflammatory markers (MMP-8), and radiographic bone density gain.

Secondary Outcomes: Probing pocket depth (PPD), plaque index (PI), and gingival index (GI).

Follow-up assessments will be performed at 1, 3, and 6 months. Data will be statistically analyzed using ANOVA and paired t-tests, with significance at p < 0.05.

The trial has been reviewed and approved by the Scientific Research Ethics Committee, Faculty of Dentistry, Kafrelsheikh University (Approval No. KFSIRB200-564, dated 24 February 2025).

Inclusion Criteria:

Adults aged 18-60 years.

Diagnosis of Stage II, Grade B periodontitis.

Probing pocket depths ≤ 5 mm with clinical attachment loss of 3-4 mm in selected sites.

Generally healthy individuals without systemic conditions affecting periodontal health.

Exclusion Criteria:

Current smokers or users of tobacco products.

Pregnant or lactating women.

Known allergy to metformin or chlorhexidine.

Use of antibiotics or anti-inflammatory drugs within the past 3 months.

History of periodontal therapy within the past 6 months.