Interdental Hygiene Methods in Young Adults (HIJA)

Effectiveness of Different Methods of Interdental Space Hygiene in Daily Practice Among Young Adults: A Randomized, Single-Blind Controlled Trial

Oral health is essential for overall well-being and systemic health. A key factor in preserving this health is maintaining the balance of the interdental microbiota, which involves regulating the quantity of pathogenic bacteria in interdental spaces (IS). These IS represent a unique ecological niche where the body has limited specific defense mechanisms, making them vulnerable to infections.

In adults, the colonization of interdental spaces by pathogenic bacteria increases the risk of periodontal diseases, which are themselves associated with non-communicable diseases such as cardiovascular diseases, diabetes, and certain types of cancer.

Preventing interdental microbiota dysbiosis from a young age is therefore a priority to maintain quality oral health and contribute to good systemic health throughout life. However, conventional brushing techniques cover only accessible tooth surfaces and cannot reach the interdental spaces. Currently, the use of interdental brushes (IDBs) is recognized as the most effective method for interdental hygiene. There are various types of IDBs, differing in several aspects that influence their effectiveness and usability. The main differences relate to their shape, size, and calibration using an interdental probe or not, allowing adaptation to different interdental space sizes. To date, only one study has demonstrated the effectiveness of daily calibrated interdental brush use in reducing dysbiosis and interdental inflammation among young adults. However, no research has yet been conducted to compare the effectiveness of the various types of IDBs available on the market (calibrated versus non-calibrated).

Study Overview

• Status: Completed
• Conditions: Periodontal Diseases; Oral Hygiene; Microbiota-related Disease
• Intervention / Treatment: Procedure: Calibrated interdental brush

• Study Type: Interventional
• Enrollment (Actual): 51
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Lyon, France
    • Service de Soins Dentaires Et D'Odontologie

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Person between 18 and 30 years old
• Person who has given free, informed, express written consent
• Person affiliated to a French social security system
• Person living or working in Lyon or the Lyon conurbation served by public transport (TCL)

Exclusion Criteria:

• Person with a smoking addiction
• Person participating in another study related to oral hygiene
• Patients at high risk of infective endocarditis
• Person with chronic pathologies
• Person having taken antibiotic treatment during the month preceding the start of the study
• Pregnant, parturient or breastfeeding woman
• Persons deprived of liberty by a judicial or administrative decision
• People receiving psychiatric care
• Persons admitted to a health or social establishment for purposes other than research
• Adults subject to a legal protection measure (guardianship, curatorship)
• Persons not affiliated to a social security scheme or beneficiaries of a similar scheme
• Person with fewer than 20 natural teeth
• Person performing interdental hygiene and/or daily mouthwashes.
• Person wearing orthodontic appliance
• Person with periodontal disease (stage ≥ II periodontal lesions according to the Chicago 2017 classification (i.e. PD ≥ 4 mm, and/or CAL ≥ 4 mm) and/or generalized (>30% of sites )), active caries or during dental care

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Calibrated interdental brush; Healthy adult volunteers (not suffering from chronic pathologies) and non-smokers, agreeing to change their interdental hygiene habits for 3 months by daily using a calibrated interdental brushes .	Procedure: Calibrated interdental brush; participants will use calibrated interdental brushes
No Intervention: Non-calibrated interdental brush; Healthy adult volunteers (not suffering from chronic pathologies) and non-smokers, agreeing to change their interdental hygiene habits for 3 months by daily using a non-calibrated interdental brushes .

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Interdental bleeding at month 3 (in percentage)	Comparison of interdental inflammation (interdental bleeding) following the daily use of calibrated versus non-calibrated interdental brushes at month 3 (T3, expressed as a percentage and assessed at four sites per tooth following probing with a periodontal probe).	Baseline (T0), 3 months after baseline (T3)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composition of the Interdental microbiome (diversity and total bacteria count)	Identification of the composition of the interdental microbiome in healthy young adults using sequencing techniques at T0, in four standardized sites (between teeth 15-16, 25-26, 35-36, and 45-46). If the specified teeth are missing, exhibit pathologies, or have diastemas preventing interdental cleaning, the sample will be taken from the nearest healthy mesial interdental space.	Baseline (T0)
Periodontal health analysis	Comparison of periodontal for all participant's teeth (plaque index, gingival index, interdental inflammation, pocket depth and loss of clinical attachment) before (T0), 1 week after baseline (T1), 1 month after baseline (T2) and 3 months after baseline (T3) following the daily use of calibrated versus non-calibrated interdental brushes	Baseline (T0), 1 week later (T1), 1 month after baseline (T2), 3 months after baseline (T3)
Periodontal health analysis - salivary pH	Comparison of periodontal for all participant's teeth (salivary pH) before (T0), 1 week after baseline (T1), 1 month after baseline (T2) and 3 months after baseline (T3) following the daily use of calibrated versus non-calibrated interdental brushes	Baseline (T0), 1 week later (T1), 1 month after baseline (T2), 3 months after baseline (T3)
Interdental microbiota at T3 (diversity and total bacteria count)	Comparison of the composition of the interdental microbiome in healthy young adults using sequencing techniques after 3 months of calibrated versus non calibrated interdental brushed, in four standardized sites (between teeth 15-16, 25-26, 35-36, and 45-46). If the specified teeth are missing, exhibit pathologies, or have diastemas preventing interdental cleaning, the sample will be taken from the nearest healthy mesial interdental space.	Baseline (T0), 3 months after baseline (T3)
Daily use acceptability of interdental brushes	Evaluation and comparison of the acceptability and ease of integration (by TFA questionnaire) of daily use of calibrated versus non-calibrated interdental brushes, 1 week after baseline (T1), 1 month after baseline (T2) and 3 months after baseline (T3)	1 week after baseline (T1), 1 month after baseline (T2), 3 months after baseline (T3)

Collaborators and Investigators

• Sponsor: Hospices Civils de Lyon
• Investigators: Principal Investigator: Stéphane VIENNOT, HCL

Study record dates

Study Major Dates

• Study Start (Actual): September 17, 2025
• Primary Completion (Actual): April 13, 2026
• Study Completion (Actual): April 13, 2026

Study Registration Dates

• First Submitted: February 17, 2025
• First Submitted That Met QC Criteria: February 24, 2025
• First Posted (Actual): February 27, 2025

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 23, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Oral health; Preventive care; Interdental hygiene; Periodontal disease prevention; Interdental microbiota
• Additional Relevant MeSH Terms: Mouth Diseases; Stomatognathic Diseases; Periodontal Diseases
• Other Study ID Numbers: 69HCL24_1272

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No