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

Official title

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

Overview

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.

Detailed description

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).

Interventions

• Procedure Arm 1 Scaling and Root Planing (SRP)
  Full-mouth supragingival and subgingival debridement performed with ultrasonic and hand instruments (Gracey curettes). SRP performed to remove plaque and calculus and root-surface decontamination. Standardized oral hygiene instruction is provided after the procedure.
• Drug Arm 2 Metformin Gel 1% (locally delivered)
  1% metformin hydrochloride formulated in a gellan-gum gel base (as per protocol). After SRP, gel is delivered subgingivally with a sterile syringe (23-gauge cannula) and left undisturbed for approximately 5 minutes; a periodontal dressing is placed for one week. Gingival crevicular fluid sampling and clinical follow-up at 1, 3, and 6 months.
• Drug Arm 3 Chlorhexidine Gel 0.2% (locally delivered)
  0.2% chlorhexidine digluconate gel prepared in carbopol base. After SRP, gel is delivered subgingivally with a sterile syringe and left undisturbed for approximately 5 minutes; a periodontal dressing is placed for one week. Clinical follow-up at 1, 3, and 6 months.

Primary outcome measures

• Change in Gingival Crevicular Fluid MMP-8 Levels [Time frame: Baseline, 1 month, and 3 months]
• Change in Clinical Attachment Level (CAL) [Time frame: Baseline, 1 month, 3 months, and 6 months]
• Change in Alveolar Bone Density [Time frame: Baseline, 3 months, and 6 months]

Secondary outcome measures (3)

• Change in Probing Pocket Depth (PPD) [Time frame: Baseline, 1 month, 3 months, and 6 months]
• Change in Gingival Index (GI) Score [Time frame: Baseline, 1 month, 3 months, and 6 months]
• Change in Plaque Index (PI) Score [Time frame: Baseline, 1 month, 3 months, and 6 months]

Eligibility criteria

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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT07215156 · KFSIRB200-564

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗