The Effect of Arginine on Biofilm Composition, Architecture and Metabolism

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

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.

Study Overview

• Status: Completed
• Conditions: Dental Caries; Microbial Colonization; Dental Plaque
• Intervention / Treatment: Other: Placebo; Other: Arginine

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aarhus, Denmark, 8000
    • Aarhus University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Single Group Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arginine solution; 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; See arm description
Placebo Comparator: Placebo; 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; See arm description

What is the study measuring?

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

Collaborators and Investigators

• Sponsor: University of Aarhus
• Investigators: Principal Investigator: Sebastian Schlafer, University of Aarhus

Study record dates

Study Major Dates

• Study Start (Actual): October 19, 2023
• Primary Completion (Actual): February 13, 2024
• Study Completion (Actual): February 13, 2024

Study Registration Dates

• First Submitted: November 13, 2023
• First Submitted That Met QC Criteria: November 13, 2023
• First Posted (Actual): November 18, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 19, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Stomatognathic Diseases; Pathologic Processes; Disease Attributes; Tooth Diseases; Dental Deposits; Tooth Demineralization; Infections; Communicable Diseases; Dental Plaque; Dental Caries
• Other Study ID Numbers: 97473

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Due to general data protection regulations, individual participant data will not be made available publicly. Summary data will be made available upon publication of the results.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No