Silver Nanoparticle vs Chlorhexidine Mouthwashes for Reducing Streptococcus Mutans and Improving Salivary pH in Children

Official title

A Randomized Clinical Trial Comparing Silver Nanoparticle and Chlorhexidine Mouthwashes on Streptococcus Mutans Levels and Salivary pH in Pediatric Patients

Overview

Dental caries remains one of the most common chronic diseases in children, with Streptococcus mutans playing a major role in its development. Chlorhexidine mouthwash is an effective antimicrobial agent but its use in pediatric patients is limited by adverse effects such as tooth staining, taste alteration, and mucosal irritation. Silver nanoparticle (AgNP) mouthwash has emerged as a potential alternative with broad-spectrum antimicrobial activity and a potentially improved safety profile. This randomized, double-blind, parallel-group clinical trial will compare the efficacy of 10 ppm silver nanoparticle mouthwash with 0.2% chlorhexidine mouthwash in reducing salivary Streptococcus mutans levels in children aged 6-12 years at high caries risk.

Detailed description

Dental caries remains the most prevalent chronic disease affecting children worldwide and continues to represent a major public health concern. The disease results from a complex interaction between dental biofilm, fermentable carbohydrates, susceptible tooth surfaces, and host factors. Among the microorganisms associated with caries development, Streptococcus mutans plays a central role because of its ability to adhere to tooth surfaces, synthesize extracellular polysaccharides, produce organic acids, and tolerate acidic environments. Consequently, reducing salivary and plaque levels of S. mutans is considered an important strategy for preventing and controlling dental caries in children at high caries risk.

Chlorhexidine gluconate is widely recognized as the reference antimicrobial mouthwash because of its broad-spectrum antibacterial activity and prolonged substantivity. Despite its effectiveness, routine use in pediatric patients may be limited by adverse effects, including tooth staining, taste alteration, oral mucosal irritation, and reduced patient acceptance during repeated use.

Silver nanoparticles (AgNPs) have attracted increasing interest as an alternative antimicrobial agent because of their broad-spectrum activity against oral microorganisms through multiple mechanisms, including disruption of bacterial cell membranes, interference with intracellular metabolic processes, and inhibition of biofilm formation. At appropriate concentrations, AgNP formulations have demonstrated favorable biocompatibility and may provide an alternative approach for reducing cariogenic bacteria while minimizing some of the undesirable effects associated with chlorhexidine.

This randomized, double-blind, parallel-group clinical trial is designed to evaluate the comparative effectiveness and safety of a silver nanoparticle mouthwash and a chlorhexidine mouthwash in children with high caries risk. The study will assess the antimicrobial effect of both interventions on salivary Streptococcus mutans while also evaluating changes in the oral environment and treatment tolerability. The findings are expected to provide evidence regarding whether silver nanoparticle mouthwash represents a suitable alternative to chlorhexidine for antimicrobial management in pediatric dentistry and to contribute to the development of safer and more acceptable preventive strategies for children at increased risk of dental caries.

Interventions

• Drug Silver nanoparticle mouthwash (10 ppm)
  Participants assigned to the experimental group will receive a 10 ppm silver nanoparticle (AgNP) mouthwash. They will rinse with 10 mL of the mouthwash for 60 seconds twice daily (morning and evening) after toothbrushing for 14 consecutive days. Participants will be instructed not to eat or drink for 30 minutes after each rinse and to maintain their usual oral hygiene practices throughout the study period.
• Drug Chlorhexidine mouthwash (0.2%)
  Participants assigned to the active comparator group will receive a 0.2% chlorhexidine gluconate mouthwash. They will rinse with 10 mL of the mouthwash for 60 seconds twice daily (morning and evening) after toothbrushing for 14 consecutive days. Participants will be instructed not to eat or drink for 30 minutes after each rinse and to maintain their usual oral hygiene practices throughout the study period.

Primary outcome measures

• Change in salivary Streptococcus mutans levels [Time frame: Baseline and Day 14]

Eligibility criteria

Inclusion criteria

• Age 6-12 years with mixed dentition.
• American Society of Anesthesiologists (ASA) physical status I or II
• High caries risk, defined as DMFT/dmft score ≥ 3, Dentocult SM Strip mutans score ≥ 2, or salivary S. mutans ≥ 10⁵ CFU/mL at screening
• Presence of at least 20 natural teeth.
• No antibiotic therapy in the preceding 3 months.
• Parent/guardian willing to provide written informed consent.
• Child assent obtained using age-appropriate methods.

Exclusion criteria

• Systemic diseases affecting salivary flow (e.g., Sjögren's syndrome, uncontrolled diabetes, cystic fibrosis).
• Special healthcare needs or developmental disabilities affecting. compliance
• Active fixed or removable orthodontic appliances.
• History of allergy to silver compounds, chlorhexidine, or mint flavoring.
• Use of any antimicrobial mouthwash in the preceding 3 months.
• Active oral mucosal lesions or periodontal disease.
• Professional fluoride treatment within the past month.
• Participation in another clinical trial 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: Yes

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Quadruple blind

Primary purpose

Prevention

Study locations

Center list to be confirmed — check the primary protocol.

Identifiers

NCT: NCT07728409 · 17-2026-0004

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗