The Effect of Arginine on Biofilm Composition, Architecture and Metabolism

Study Overview
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Brief Summary
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Arginine is an adjunct to oral health care that has the potential to modulate the composition and activity of the microbial community of dental biofilms towards a health-related status without harmful effects for the resident oral microbiota. The aim of the study is to investigate the effects of arginine treatment compared to placebo on the composition, metabolism, and microarchitecture of biofilms grown in situ in the oral cavity of caries-active participants.

Official Title
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The Effect of Arginine on Biofilm Composition, Architecture and Metabolism in Caries-active Patients: a Split-mouth in Situ Trial

Conditions
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Dental Caries, Dental Plaque, Microbial Colonization

Intervention / Treatment
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* Other: Arginine
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males and females ≥ 18 years old. Three or more active carious lesions. Anatomically possible to manufacture an intraoral lower-jaw splint. Able to understand and follow instructions, as well as to read and sign the informed consent form. Exclusion Criteria: History of allergies towards any of the ingredients in the test products Self-reported pregnant or nursing Antibiotic or anti-inflammatory medication within 90 days of the screening visit. Orthodontic appliances, including retainers, or removable partial dentures. Self-reported serious medical conditions.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: Split-mouth design
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Arginine solution<br>Arginine treatment is performed outside the oral cavity (ex vivo) by immersing one side of a splint into a solution of arginine 1.5% (w/v). Treatment is performed 3 times a day for 30 min. | Other: Arginine<br>* See arm description<br>|
| Placebo Comparator: Placebo<br>Placebo treatment is performed outside the oral cavity (ex vivo) by immersing one side of a splint into distilled water. Treatment is performed 3 times a day for 30 min. | Other: Placebo<br>* See arm description<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Biofilm pH | Extracellular biofilm pH measured after sucrose challenge using pH ratiometry | Measured after in situ biofilm growth | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Biofilm microbial composition | Microbial community of dental biofilms determined by 16S rRNA gene sequencing. Distribution of specific microbial targets in the biofilms is visualized by fluorescence in situ hybridization. | Analyzed after in situ biofilm growth | 
| Biofilm matrix architecture | Matrix components are visualized in the dental biofilms by confocal microscopy. | Analyzed after of in situ biofilm growth | 
| Biofilm thickness | Measured using confocal laser scanning microscopy and/or optical coherence tomography. | Measured after in situ biofilm growth |