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Completed

NCT Number: NCT07767721

Comparison of Three Tongue Cleaners for Removing Tongue Coating

This randomised three-period crossover study compared the effectiveness of three tongue-cleaning devices - a bristled tongue brush, a plastic tongue scraper and a metal tongue scraper - in removing tongue biofilm. Thirty healthy volunteers aged 18 to 30 used each device once daily for 14 consecutive days, with 7-day washout periods between devices during which no tongue cleaning was performed. Tongue biofilm was measured objectively by Quantitative Light-induced Fluorescence-Digital (QLF-D) imaging, alongside the visual Tongue Coating Index, salivary pH, and participant-reported acceptability including gag reflex.

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Key information

Conditions

Tongue Coating Dental Deposits Dental Plaque Oral Biofilm Oral Hygiene Stomatognathic Diseases Tooth Diseases

Age range

18 year–30 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Istanbul Kent University, Faculty of Dentistry

Istanbul, Turkey (Türkiye)

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy volunteers aged 18 to 25 years
  • No professional dental cleaning within the previous two weeks
  • Willing to maintain usual toothbrushing and interdental hygiene practices throughout the study period

Exclusion criteria

  • -History of significant systemic disease (e.g. diabetes mellitus, immune disorders)
  • Clinical salivary gland dysfunction or self-reported xerostomia
  • Active oral or mucosal infection (e.g. severe periodontitis, extensive caries)
  • Active mucosal lesions
  • Fixed orthodontic appliances
  • Conditions predisposing to severe gagging beyond normal clinical sensitivity
  • Use of topical or systemic antimicrobials or antibiotics within the previous month

Treatment and study plan

Bristled tongue brush

Device

Over-the-counter tongue brush with a bristled cleaning surface (R.O.C.S. Pro Lingua, Moscow, Russia). Participants used the device once daily for 14 consecutive days, performing a single-directional sweeping motion from the posterior vallate papillae to the anterior tip of the tongue dorsum, using gentle self-regulated pressure sufficient to alter tissue curvature without causing mucosal discomfort.

Plastic tongue scraper

Device

Over-the-counter smooth plastic tongue scraper (Pearldent, DentaRAM, Istanbul, Türkiye). Participants used the device once daily for 14 consecutive days, performing a single-directional sweeping motion from the posterior vallate papillae to the anterior tip of the tongue dorsum, using gentle self-regulated pressure sufficient to alter tissue curvature without causing mucosal discomfort.

Metal tongue scraper

Device

Over-the-counter rigid metal tongue scraper (Glimo, Haltron, Istanbul, Türkiye).

Participants used the device once daily for 14 consecutive days, performing a single-directional sweeping motion from the posterior vallate papillae to the anterior tip of the tongue dorsum, using gentle self-regulated pressure sufficient to alter tissue curvature without causing mucosal discomfort.

Primary outcomes

  1. Change From Baseline in Maximum Fluorescence Loss (Delta F Max) of Tongue Dorsum Biofilm Assessed by Quantitative Light-Induced Fluorescence-Digital (QLF-D) Imaging

    Time frame: Baseline (Day 1), Day 7 and Day 14 of each 14-day intervention period

Secondary outcomes

  1. Change From Baseline in Average Fluorescence Loss (Delta F Average)

    Time frame: Baseline (Day 1), Day 7 and Day 14 of each period

  2. Change From Baseline in Total Fluorescence Loss (Delta Q)

    Time frame: Baseline (Day 1), Day 7 and Day 14 of each period

  3. Change From Baseline in White Spot Area

    Time frame: Baseline (Day 1), Day 7 and Day 14 of each period

  4. Change From Baseline in White Spot Delta R

    Time frame: Baseline (Day 1), Day 7 and Day 14 of each period

  5. Change From Baseline in Tongue Coating Index (TCI)

    Time frame: Baseline (Day 1), Day 7 and Day 14 of each period

    The tongue dorsum is divided into nine regions (three posterior, three middle, three anterior). Each region is scored for coating thickness (0 = no coating,

    • = thin, 2 = thick) and for discolouration (0 = none, 1 = white,
    • = yellow/light brown, 3 = brown), following Shimizu et al. Higher scores indicate a greater quantity of tongue coating.

  6. Change From Baseline in Unstimulated Salivary pH

    Time frame: Baseline (Day 1), Day 7 and Day 14 of each period

    Unstimulated whole saliva collected with participants seated after refraining from eating and drinking for at least 60 minutes. Measured immediately with MQuant pH indicator strips (Merck KGaA, Darmstadt, Germany); the median of two readings was recorded.

  7. Participant-Reported Device Acceptability

    Time frame: End of study (Day 14 of the third period)

  8. Participant-Reported Gag Reflex Severity

    Time frame: End of study (Day 14 of the third period)

Sponsors and collaborators

Lead sponsor

Istanbul Kent University

Other

Registry information

Official study title

Investigation Into the Effectiveness of Tongue Cleaning With Different Materials Using Visual and Fluorescence Methods

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Aug 17, 2026
Registry last updated
Aug 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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