Effect of Powered Toothbrushing and Dental Flossing Sequence on Dental Plaque Removal

July 29, 2026 updated by: Sema Merve Altıngöz, Lokman Hekim University

Does the Sequence of Powered Toothbrushing and Dental Flossing Affect Dental Plaque Removal? A Randomized Crossover Clinical Trial

This randomized crossover clinical trial evaluated whether the sequence of powered toothbrushing and dental flossing affects dental plaque removal. Forty-six systemically and periodontally healthy participants were randomly assigned to one of two oral hygiene sequences. In Group 1, participants performed powered toothbrushing followed by dental flossing during the first period and dental flossing followed by powered toothbrushing during the second period. Group 2 performed the same procedures in the opposite order. The two intervention periods were separated by a 15-day washout period, with professional prophylaxis performed to standardize oral hygiene conditions. Dental plaque was assessed before and after the oral hygiene procedures using the Plaque Index (PI) and the Turesky modification of the Quigley-Hein Plaque Index (TQHPI). The study aimed to determine whether performing powered toothbrushing before or after dental flossing results in greater plaque removal.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
46

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Locations

  • Turkey (Türkiye)
      • Ankara, Turkey (Türkiye)
        • Lokman Hekim University Faculty of Dentistry

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age between 18 and 30 years
  • Systemically healthy
  • Presence of at least 22 natural teeth
  • No signs of active periodontal disease
  • Ability to comply with the study procedures and oral hygiene instructions
  • Provision of written informed consent

Exclusion Criteria:

  • Antibiotic use within the previous 3 months
  • Smoking
  • Presence of systemic conditions known to affect periodontal health, including diabetes mellitus or immune-mediated disorders
  • Ongoing orthodontic treatment
  • Presence of fixed prostheses, crowns, or extensive restorations that could interfere with plaque assessment
  • Professional periodontal therapy within the previous 3 months
  • Pregnancy or lactation
  • Severe dental crowding

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: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Brush-Floss Sequence (Group 1)
Participants assigned to this sequence will first perform powered toothbrushing followed by dental flossing during the first study period. After the washout period, the order of the oral hygiene procedures will be reversed, with dental flossing performed before powered toothbrushing during the second study period.
Behavioral: Powered Toothbrushing
Participants will perform oral hygiene using a powered toothbrush according to the standardized study protocol. The intervention will be applied as part of the assigned brushing-flossing sequence.
Behavioral: Dental Flossing
Participants will perform interdental cleaning using dental floss according to the standardized study protocol. The intervention will be applied as part of the assigned brushing-flossing sequence.
Experimental: Floss-Brush Sequence (Group 2)
Participants assigned to this sequence will first perform dental flossing followed by powered toothbrushing during the first study period. After the washout period, the order of the oral hygiene procedures will be reversed, with powered toothbrushing performed before dental flossing during the second study period.
Behavioral: Powered Toothbrushing
Participants will perform oral hygiene using a powered toothbrush according to the standardized study protocol. The intervention will be applied as part of the assigned brushing-flossing sequence.
Behavioral: Dental Flossing
Participants will perform interdental cleaning using dental floss according to the standardized study protocol. The intervention will be applied as part of the assigned brushing-flossing sequence.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Residual Plaque Index
Time Frame: Immediately after completion of the assigned oral hygiene sequence following 48 hours of plaque accumulation, in each study period.
Residual dental plaque was assessed immediately after completion of the assigned oral hygiene sequence using the Plaque Index (PI). Higher scores indicate greater residual plaque accumulation.
Immediately after completion of the assigned oral hygiene sequence following 48 hours of plaque accumulation, in each study period.
Residual Buccal Turesky Modified Quigley-Hein Plaque Index (TQHPI)
Time Frame: Immediately after completion of the assigned oral hygiene sequence following 48 hours of plaque accumulation, in each study period.
Following plaque disclosure, residual plaque on the buccal tooth surfaces was assessed using the Turesky Modified Quigley-Hein Plaque Index (TQHPI), scored from 0 to 5, with higher scores indicating greater residual plaque accumulation.
Immediately after completion of the assigned oral hygiene sequence following 48 hours of plaque accumulation, in each study period.
Residual Lingual Turesky Modified Quigley-Hein Plaque Index (TQHPI)
Time Frame: Immediately after completion of the assigned oral hygiene sequence following 48 hours of plaque accumulation, in each study period.
Following plaque disclosure, residual plaque on the lingual tooth surfaces was assessed using the Turesky Modified Quigley-Hein Plaque Index (TQHPI), scored from 0 to 5, with higher scores indicating greater residual plaque accumulation.
Immediately after completion of the assigned oral hygiene sequence following 48 hours of plaque accumulation, in each study period.

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Lokman Hekim University

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 (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 2, 2026

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 15, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 15, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 27, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 29, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 30, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 30, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 29, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • LHU-2026-164

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

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.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings