Accepted for/Published in: JMIR Research Protocols
Date Submitted: Oct 1, 2025
Date Accepted: Oct 27, 2025
(closed for review but you can still tweet)
Warning: This is an author submission that is not peer-reviewed or edited. Preprints - unless they show as "accepted" - should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.
Effectiveness of different methods of interdental hygiene in daily practice among young adults: Protocol for a randomized, single-blind controlled trial
ABSTRACT
Background:
Interdental spaces are particularly susceptible to biofilm accumulation and gingival inflammation, which contribute to periodontal diseases and their systemic associations. While interdental brushes (IDBs) are recognized as the most effective method of interdental cleaning, their efficacy depends on proper adaptation to the interdental space. Calibration with a periodontal probe may enhance their effectiveness and comfort. However, evidence directly comparing calibrated and non-calibrated IDBs, especially in young adults—a key target group for preventive strategies—remains limited. The HIJA trial was designed to address this gap.
Objective:
To assess the effectiveness of calibrated interdental brushes in improving interdental health in young adults compared with non-calibrated brushes.
Methods:
The HIJA (Hygiene of Interdental Junctions in Adults) trial is a monocentric, randomized, controlled, single-blind, parallel-arm study. Fifty-six healthy, non-smoking adults aged 18–30 will be randomized (1:1) to receive either calibrated or non-calibrated IDBs. Participants will perform daily interdental cleaning in addition to conventional toothbrushing for 3 months. The primary outcome is the change in bleeding on probing (BoP) proportion at 3 months. Secondary outcomes include interdental microbiota composition (16S rRNA sequencing), periodontal indices (plaque index, gingival index, probing depth, clinical attachment loss), and acceptability assessed with the Theoretical Framework of Acceptability questionnaire at 1, 2, and 3 months. Adherence will be monitored through a participant logbook.
Results:
HIJA trial will generate evidence on whether calibrated interdental brushes provide additional benefits over non-calibrated brushes in reducing interdental inflammation and improving oral health in young adults.
Conclusions:
HIJA findings could contribute to the implementation of clinical guidelines and preventive strategies for interdental hygiene in daily practice. Clinical Trial: Trial Registration: ClinicalTrials.gov NCT06848790
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