Breaking the Cycle: Real-Time Family Oral Microbial Transmission Patterns as Intervention Targets

June 25, 2026 updated by: University of Alberta

This study aims to understand how oral bacteria that cause tooth decay and gum disease spread among family members and whether treating multiple family members can reduce the return of these bacteria after dental treatment.

Families with children aged 5-12 years will be recruited from university dental clinics. Participants will be assigned to one of three treatment groups: treatment for the child only, treatment for the child and parents, or treatment for all family members. Researchers will collect oral bacterial samples from family members before and after treatment and will monitor close-contact interactions within the household using wearable proximity-tracking devices.

The study will also collect information about oral health habits, family interactions, and environmental factors that may influence bacterial transmission. By combining bacterial DNA analysis with information about family contact patterns, researchers hope to better understand how oral bacteria are shared within households and whether family-based treatment approaches can reduce bacterial recolonization after dental therapy.

The results of this study may help improve strategies for preventing childhood tooth decay and gum disease by addressing family-level sources of bacterial transmission.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Oral diseases, including dental caries and periodontal diseases, are among the most prevalent chronic diseases worldwide. Although oral pathogens are known to be transmissible, the mechanisms by which disease-associated bacteria spread within families and contribute to recolonization after treatment remain poorly understood.

This randomized clinical trial will investigate familial oral microbial transmission and the role of household-level interventions in modifying microbial recolonization following professional dental therapy. Forty-five families will be recruited from university dental clinics and randomized into one of three intervention groups: (A) child-only plaque disruption, (B) child plus parent plaque disruption, or (C) plaque disruption for all family members. Eligible households must include at least two children aged 5-12 years and at least one adult requiring periodontal therapy or a child at high risk of disease recurrence.

Oral microbial samples will be collected from all participating family members at multiple oral sites, including saliva, buccal mucosa, tongue, supragingival plaque, and subgingival plaque. Follow-up sampling will occur at 1 week, 4-6 weeks, and 3 months after treatment. Participants will complete oral health and demographic questionnaires, and all family members will wear Ultrawide Band (UWB) proximity-tracking devices to quantify real-time interpersonal contact patterns within the household. Airborne microbial sampling will also be performed to investigate potential aerosol-mediated transmission pathways.

Bacterial DNA sequencing, source-tracking algorithms, and quantitative PCR analyses will be used to identify sources of microbial recolonization and quantify transmission among family members. Generalized Linear Mixed Models will be used to examine associations between microbial transmission, proximity measures, demographic variables, and household characteristics.

The primary objective is to determine whether reducing familial pathogen burden through household-level treatment decreases recolonization of oral pathogens following dental therapy. Secondary objectives include characterizing contact-dependent and airborne transmission pathways and identifying factors associated with oral microbial transmission within families.

Study Type

Interventional

Enrollment (Estimated)

225

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Canada
    • Alberta
      • Edmonton, Alberta, Canada, T6G2L7
        • Kaye Edmonton Clinic - University of Alberta School of Dentistry
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Families with at least two children aged 5-12 years living in the same household.
  • least one parent or guardian diagnosed with Stage II or III periodontitis requiring non-surgical periodontal therapy.
  • At least one child who has undergone caries treatment and is considered at high risk for disease recurrence.
  • Willingness of all participating household members to provide oral samples and participate in study procedures.
  • Ability of participants or their legal guardians to provide informed consent, and assent from children where applicable.

Exclusion Criteria:

  • Children living in multiple households or shared-custody arrangements during the study period.
  • Households unable to complete study visits or follow-up procedures.
  • Individuals unwilling or unable to comply with study procedures.
  • Individuals who do not provide informed consent or assent, where applicable.
  • Medical or behavioral conditions that, in the opinion of the investigators, would preclude safe participation in the study.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Child-Only Treatment
The primary child participant receives professional dental plaque disruption and oral hygiene intervention. Other household members do not receive study-related treatment.
Procedure: Professional Dental Plaque Disruption
Professional dental plaque disruption and oral hygiene treatment performed to reduce oral bacterial burden. The intervention may include professional dental cleaning, plaque removal, and periodontal therapy as clinically indicated according to study group assignment.
Experimental: Child Plus Parents Treatment
The primary child participant and both parents receive professional dental plaque disruption and oral hygiene intervention
Procedure: Professional Dental Plaque Disruption
Professional dental plaque disruption and oral hygiene treatment performed to reduce oral bacterial burden. The intervention may include professional dental cleaning, plaque removal, and periodontal therapy as clinically indicated according to study group assignment.
Experimental: Whole-Family Treatment
All participating household members receive professional dental plaque disruption and oral hygiene intervention using a family-wide treatment approach.
Procedure: Professional Dental Plaque Disruption
Professional dental plaque disruption and oral hygiene treatment performed to reduce oral bacterial burden. The intervention may include professional dental cleaning, plaque removal, and periodontal therapy as clinically indicated according to study group assignment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Proportional Contribution of Familial Sources to Oral Microbial Recolonization
Time Frame: 3 Months
Percentage contribution (%) of each household member to the primary child's post-treatment oral microbial recolonization, estimated using bacterial DNA sequencing and Bayesian microbial source-tracking (STENSL).
3 Months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Oral Microbial Community Reconstitution
Time Frame: Baseline to 3 Months
Oral microbial community reconstitution assessed by relative abundance (%) of oral bacterial taxa and microbial alpha diversity of the oral microbiota, measured using 16S rRNA gene sequencing.
Baseline to 3 Months
Frequency of Close-Contact Interactions Measured using Ultrawide Band (UWB)
Time Frame: 1 Week
Number of close-contact interactions (count) between household members measured using wearable Ultrawide Band (UWB) proximity sensors.
1 Week
Correlation Between Close-Contact Duration and Familial Contribution to Oral Microbial Recolonization
Time Frame: Baseline to 3 Months
Correlation between cumulative close-contact duration (minutes), measured using wearable Ultrawide Band (UWB) proximity sensors, and the proportional contribution (%) of each family member to the primary child's oral microbial recolonization, estimated from bacterial DNA sequencing data using the Bayesian microbial source-tracking algorithm (STENSL).
Baseline to 3 Months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Alberta

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 30, 2026

Primary Completion (Estimated)

March 30, 2028

Study Completion (Estimated)

June 30, 2028

Study Registration Dates

First Submitted

June 22, 2026

First Submitted That Met QC Criteria

June 25, 2026

First Posted (Actual)

June 30, 2026

Study Record Updates

Last Update Posted (Actual)

June 30, 2026

Last Update Submitted That Met QC Criteria

June 25, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Pro00164902

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

A decision regarding sharing of individual participant data (IPD) has not yet been made. Data sharing plans will be determined in accordance with University of Alberta policies, participant consent, and applicable ethics requirements.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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