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Gag ReflexNCT07493200

The Effect of Earplugs on Gag Reflex and Patient Comfort in Root Canal Treatment

A study testing Custom-Made Silicone Earplug in people with Gag Reflex, run by Beyhan Başkan at 1 site in Turkey (Türkiye).

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

This study evaluated whether wearing an earplug during root canal treatment reduces the gag reflex and the stress it causes. Forty adults who had a severe or very severe gag reflex were randomly divided into two groups. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Gag Reflex
What is being tested?
Custom-Made Silicone Earplug
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
40 participants
Where
1 siteTurkey (Türkiye)
Study dates
12 May 2025to 5 Feb 2026
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age over 18 years Need for endodontic treatment Score of 4 (severe gagging: occurs with all forms of treatment) or 5 (very severe gagging: makes treatment impossible) on the Dickinson and Fiske Gagging Severity Index (GSI)

Who cannot join

  • Systemic disease Pregnancy or lactation Diagnosed central or peripheral nervous system disorders Use of anti-emetic medication Ear infection or structural abnormality of the external auditory canal

Trial locations and contacts

1 site in 1 country.

Turkey (Türkiye)1 site
  • Kahramanmaraş Sütçü İmam Universty

    Kahramanmaraş, 46140

Other trials in Turkey (Türkiye)

About this study

Official title: The Effect of Using Custom-Made Silicone Earplips on Gag Reflex Severity, Behavioral Responses, and Salivary Alpha-Amylase Levels as a Stress Biomarker in Patients Undergoing Root Canal Treatment: A Randomized Controlled Trial

This study evaluated whether wearing an earplug during root canal treatment reduces the gag reflex and the stress it causes. Forty adults who had a severe or very severe gag reflex were randomly divided into two groups. One group received an earplug in the ear opposite to the side being treated; the other group received standard treatment without an earplug. The severity of the gag reflex was scored by an observer, stress was measured using a saliva sample (salivary alpha-amylase), and treatment time and gag-related interruptions were recorded. The results showed that the earplug group had lower gag-reflex scores, lower stress levels, and shorter treatment times with fewer interruptions. No side effects were reported. These findings suggest that a simple, low-cost earplug may help patients who gag easily during dental treatment.

Read the detailed description

Background: An exaggerated gag reflex is a common problem during dental treatment, especially in endodontics, where uninterrupted working time and moisture control are essential. Pharmacological approaches carry risks, and evidence for non-pharmacological methods is limited. Earplug stimulation of the external auditory canal has been proposed as a simple, non-invasive way to suppress the gag reflex.

Objective: To evaluate the effect of earplug application during endodontic treatment on gag-reflex severity, physiological stress (salivary alpha-amylase, sAA), and clinical efficiency (treatment time and gag-related interruption ratio).

Methods: This prospective, randomized controlled trial enrolled 40 adults with severe or very severe gagging (Dickinson-Fiske Gagging Severity Index grade 4-5) requiring endodontic treatment. Participants were randomly allocated 1:1 to an earplug group or a control group. A custom-moulded silicone earplug was placed in the ear contralateral to the operating field. The operator and the outcome assessor were blinded by an identical adhesive ear cover applied to all participants; participants could not be blinded. Gag-reflex severity was scored with an 8-item behavioural scale (0-8). Unstimulated whole saliva was collected before and after treatment for sAA measurement. Total treatment time and gag-related interruption time were recorded, and the interruption ratio was calculated as (interruption time / total treatment time) × 100. Non-parametric tests and baseline-adjusted ANCOVA on log-transformed sAA were used.

Results: The earplug group had a lower behavioural gag-reflex score (median 3.0 vs 5.5; p < 0.01) and a more favourable severity distribution (trend p < 0.01). sAA decreased after treatment with the earplug but increased in controls (median change -31.8% vs +76.2%); baseline-adjusted post-treatment sAA was 59% lower with earplug use (geometric mean ratio 0.41, 95% CI 0.32-0.53; p < 0.001). Treatment time and the interruption ratio were markedly lower with earplug use (both p < 0.001). No adverse effects were observed.

Conclusions: Earplug application during endodontic treatment was associated with reduced gag-reflex severity, an attenuated physiological stress response, and improved procedural efficiency. As a simple, inexpensive, non-invasive technique, the earplug may be a useful adjunct for managing severe gagging in endodontic practice. Larger, multi-centre trials with patient-reported outcomes are warranted.

Trial registration: ClinicalTrials.gov, NCT07493200.

Conditions
Gag Reflex
Being tested
Custom-Made Silicone Earplug
Keywords
Salivary Alpha-Amylase, Root Canal Treatment, Randomized Controlled Trial
Medical subject headings
Gagging

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Custom-Made Silicone EarplugDevice

    A personalized earplug fabricated from a soft, two-component addition-cure silicone (C-type silicone), commonly used for dental impressions. The two components are mixed according to the manufacturer's instructions and gently injected into the patient's external auditory canal on the side contralateral to the tooth receiving treatment. The silicone is allowed to polymerize for approximately 2-3 minutes, creating a custom-fit plug that conforms precisely to the individual contours of the ear canal. This ensures comfortable, continuous, and gentle tactile stimulation to the walls of the ear canal throughout the entire root canal procedure. The earplug is removed at the end of the treatment and is for single-patient use only. No other devices or pharmacological agents are used in conjunction with this intervention.

Study groups in NCT07493200
Study groupRoleWhat they receive
Experimental GroupExperimentalPatients in this group (n=20) will have a custom-made silicone earplug placed in the ear opposite the side where the dentist is working during their root canal treatment. The earplug is fabricated immediately before the procedure using soft silicone material to ensure a comfortable, personalized fit. No other pharmacological or behavioral interventions for gag reflex control will be used.
Receives: Device: Custom-Made Silicone Earplug
Control GroupNo interventionPatients in this group (n=20) will receive standard root canal treatment without any earplug placement. No interventions for gag reflex control will be used. All outcome measures (gag reflex severity, behavioral responses, treatment pause ratio, salivary alpha-amylase) will be collected in the same manner as for the experimental group.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Behavioural Gag-Reflex Score

    An 8-item behavioural observation scale (0-8) was used to quantify the intraoperative gag response. One point was assigned for each of: eye-squeezing, sweating, physical contraction, withdrawal, groaning, crying, breath-holding, and increased salivation. The total score was categorised as Mild (0-2), Moderate (3-4), Severe (5-6), or Very Severe (7-8).

    Measured: Throughout the root canal procedure (continuous observation by a blinded assessor)

Secondary outcomes (4)
  1. Behavioural Gag-Reflex Severity Distribution

    The total 8-item behavioural score (0-8) was categorised as Mild (0-2), Moderate (3-4), Severe (5-6), or Very Severe (7-8). The distribution of these categories after treatment was compared between groups using the Cochran-Armitage trend test.

    Measured: Throughout the root canal procedure

  2. Gag-Related Interruption Ratio

    The cumulative duration of gag-related pauses was divided by total treatment time and multiplied by 100. Total treatment time was measured from the start of access-cavity preparation to completion of the root-canal filling.

    Measured: Throughout the procedure

  3. Salivary α-Amylase Activity

    Unstimulated whole saliva was collected before and after treatment, centrifuged (10,000 × g, 10 min, 4 °C), and stored at -80 °C. sAA activity was measured colorimetrically using a commercial kit (Elabscience, Cat. No. E-BC-K007-M) based on the DNS method; optical density was read at 540 nm.

    Measured: Immediately before and immediately after the procedure

  4. Total Treatment Time

    Time from start of access-cavity preparation to completion of root-canal filling, measured with a digital stopwatch.

    Measured: Throughout the procedure

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted25 Mar 2026
  2. Study start12 May 2025
  3. Primary completion5 Feb 2026
  4. Study completion5 Feb 2026

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Participants are randomly assigned to one of two parallel groups: an experimental group receiving the earplug intervention and a control group receiving no intervention.
Masking
Double blind
Who is masked
Investigator, Outcomes assessor
Enrolment
40 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07493200
Sponsor's protocol ID
HRÜ/25.09.54
Status last verified
Sep 2026
First submitted
19 Mar 2026
Last updated
5 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: De-identified individual participant data (demographic, behavioural, salivary α-amylase, and procedural time data) will be shared. Requests should be directed to the corresponding author.

Questions about this trial

What is this clinical trial studying?

A study testing Custom-Made Silicone Earplug in people with Gag Reflex, run by Beyhan Başkan at 1 site in Turkey (Türkiye).

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 5 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Behavioural Gag-Reflex Score (time frame: Throughout the root canal procedure (continuous observation by a blinded assessor)). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Oct 2026.

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