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Probiotic Nanofiber Floss and Subgingival Pathogen Suppression

Probiotic-containing Nanofiber-based Dental Floss Suppresses Subgingival Red Complex Periopathogens: A Randomized Double-blind Crossover Study

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07149493
Enrollment
33
Registered
2025-09-02
Start date
2022-02-01
Completion date
2022-06-24
Last updated
2025-09-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Dental Hygiene, Gingivitis and Periodontal Diseases, Oral Microbiome, Periodontal Health, Prevention of Dental Caries, Probiotics, Periodontitis

Keywords

probiotics, dental floss, nanofibers, subgingival biofilm, Ligilactobacillus salivarius, red complex, oral microbiome

Brief summary

This randomized, double-blind, crossover clinical trial evaluated the effect of a probiotic-containing nanofiber dental floss on subgingival red complex periopathogens and gingival health in periodontally healthy individuals. Thirty male participants underwent two 14-day flossing interventions (probiotic floss and placebo floss), separated by a 14-day washout period. Clinical and microbiological parameters were assessed using standardized indices and multiplex qPCR. This study was conducted prospectively but is being registered retrospectively to ensure transparency and compliance with NIH guidelines.

Detailed description

The study aimed to validate a targeted subgingival delivery method using Ligilactobacillus salivarius-infused nanofiber floss. Participants received both floss types in a crossover design. Clinical parameters (Approximal Plaque Index and Sulcus Bleeding Index) and microbiological markers (presence of L. salivarius, red complex pathogens, total bacterial DNA) were measured at multiple timepoints. DNA analysis was performed using validated multiplex qPCR protocols. Statistical analysis included non-parametric tests and correlation models. The study was ethically approved and conducted prospectively, but is being registered retrospectively to ensure transparency and support future publication. Retrospective Registration Note: This study was originally designed as a method validation investigation to refine subgingival probiotic delivery techniques using a newly developed nanofibre dental floss containing Ligilactobacillus salivarius. At the time of ethics approval and initiation (February 2022), the study was not classified as a clinical trial. However, subsequent interpretation of NIH guidelines suggests that the randomized, blinded, crossover design involving a health-related behavioral intervention meets criteria for interventional clinical research. Accordingly, the investigators now recognize that the study should be registered as a clinical trial. The research team is submitting this retrospective registration to ensure transparency and support future publication. No participant-level outcomes have been modified post hoc, and all data were collected prospectively under full ethical oversight.

Interventions

DEVICEPlacebo nanofiber floss

Identical floss without probiotic coating, used under the same conditions.

DEVICEProbiotic nanofiber floss

Nanofiber floss infused with Ligilactobacillus salivarius (strain BCRC 14759), used twice daily for 14 days.

Sponsors

Czech Technology Agency
CollaboratorUNKNOWN
Ministry of Health, Czech Republic
CollaboratorOTHER_GOV
RECETOX
CollaboratorUNKNOWN
The University Hospital Brno
CollaboratorUNKNOWN
St. Anne's University Hospital Brno, Czech Republic
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
SUPPORTIVE_CARE
Masking
TRIPLE (Subject, Caregiver, Investigator)

Masking description

Masking in this study was double-blind. Both participants and investigators were unaware of which type of dental floss-probiotic nanofiber floss or placebo floss-was being used during each phase of the trial. This design was implemented to minimize bias in participant behavior and outcome assessment, ensuring objective evaluation of clinical indices and microbiological results.

Intervention model description

Crossover Assignment

Eligibility

Sex/Gender
MALE
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* Male adults (≥18 years) of Czech or Slovak nationality * ≥20 own teeth * Good oral hygiene * Maximum Stage 2 periodontitis

Exclusion criteria

* Immunocompromised status * Systemic illness * Antibiotic use within 2 months * Smoking * Probiotic use during study

Design outcomes

Primary

MeasureTime frameDescription
Change in Approximal Plaque Index (API)14 days of each interventionComparison of clinical indices between pre and post probiotic OR placebo floss periods. Plaque present - 1, not present - 0. Assessment using a probe, one value per tooth.
Change in Sulcus Bleeding Index (SBI)14 days of each interventionComparison of clinical indices between pre and post probiotic OR placebo floss periods. Bleeding - 1, not bleeding - 0. Upon probing, one value per tooth.

Secondary

MeasureTime frameDescription
Detection of L. salivarius DNA in subgingival plaque14 days of assigned interventionDetection of L. salivarius DNA in subgingival plaque by multiplex qPCR
Quantification of red complex pathogens (P. gingivalis, T. denticola, T. forsythia)14 days of assigned interventionQuantification of red complex pathogens (P. gingivalis, T. denticola, T. forsythia) with multiplex qPCR
Total bacterial DNA load14 days of assigned interventionqPCR

Countries

Czechia

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026