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NCT Number: NCT07493200

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

Background:

Root canal treatment is a common dental procedure used to save infected teeth. However, some patients experience a strong gag reflex during the treatment. This reflex can make it very difficult for the dentist to work, cause significant stress for the patient, and prolong the procedure. Current methods to control the gag reflex, such as anesthesia or sedation, can be complicated, require special equipment, or have side effects. Therefore, finding a simple, safe, and effective method to manage this reflex is important.

Objective:

This study aims to investigate whether using a simple, custom-made silicone earplug can help reduce the gag reflex, improve patient comfort, and lower stress levels during root canal treatment. The earplug is thought to work by creating a mild sensory distraction in the ear canal, which may interfere with the nerve signals responsible for triggering the gag reflex.

Participants:

The study will include 40 adult patients who have a severe or very severe gag reflex (scores 4 or 5 on the Dickinson and Fiske Gagging Severity Index) and require root canal treatment.

Methods:

Participants will be randomly divided into two equal groups:

* Experimental Group (20 patients): These patients will have a custom-made silicone earplug placed in the ear opposite the side where the dentist is working during their root canal treatment. * Control Group (20 patients): These patients will receive the same root canal treatment but without an earplug.

For all participants, the investigators will measure:

1. Gag Reflex Severity: The intensity of the gag reflex will be recorded using the Dickinson and Fiske index. 2. Behavioral Responses: Patient discomfort will be assessed by observing specific behaviors like eye squeezing, hand clenching, or groaning, using a simple scoring system. 3. Treatment Duration: The total treatment time and any pauses caused by the gag reflex will be timed and recorded. 4. Stress Levels: To objectively measure stress, saliva samples will be taken from each patient before and after the treatment. These samples will be analyzed in a laboratory to measure the level of alpha-amylase, an enzyme that increases with stress.

Expected Outcomes:

The investigators expect that patients in the earplug group will experience a less severe gag reflex, show fewer signs of discomfort, have fewer interruptions during their treatment, and have lower stress levels (indicated by lower alpha-amylase in their saliva) compared to the control group. If successful, this simple technique could offer a safe and easily applicable way to improve the dental experience for patients troubled by a gag reflex.

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This study is active but is not currently recruiting participants.

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Key information

Conditions

Gag Reflex Gagging Pathological Conditions, Signs and Symptoms Signs and Symptoms Signs and Symptoms, Digestive

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Kahramanmaraş Sütçü İmam Universty

Kahramanmaraş, 46140, Turkey (Türkiye)

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Adult patients aged 18 years and older.
  • Patients requiring non-surgical root canal treatment on a permanent tooth.
  • Patients classified with a severe (score 4) or very severe (score 5) gag reflex according to the Dickinson and Fiske Gagging Severity Index.
  • Patients who provide written informed consent to participate in the study.

Exclusion criteria

  • Patients with a mild or moderate gag reflex (Dickinson and Fiske scores 1, 2, or 3).
  • Patients with any known ear pathology, anatomical anomaly of the ear canal, or active ear infection that would preclude the use of an earplug.
  • Patients with a history of vertigo or balance disorders.
  • Patients with medical conditions that could affect salivary flow or composition (e.g., Sjögren's syndrome, uncontrolled diabetes).
  • Patients taking medications that could influence salivary alpha-amylase levels (e.g., systemic corticosteroids, psychotropic drugs).
  • Pregnant or breastfeeding women.
  • Patients unable to provide informed consent or comply with the study protocol.

Treatment and study plan

Custom-Made Silicone Earplug

Device

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.

Primary outcomes

  1. Gag Reflex Severity

    Time frame: At the time of the root canal procedure (single time point during the most challenging part of treatment)

    The severity of the gag reflex will be assessed using the Dickinson and Fiske Gagging Severity Index, a 5-point ordinal scale: 1=Normal (very mild, occasional, controllable by patient), 2=Mild (control achieved with support from dental team), 3=Moderate (consistent, limits treatment options), 4=Severe (occurs with any type of treatment, including simple visual examination), 5=Very Severe (affects patient behavior and dental visits, makes treatment impossible). The score will be recorded by the operator at the most challenging point of the root canal procedure (e.g., during rubber dam placement or access cavity preparation).

Secondary outcomes

  1. Behavioral Response Score

    Time frame: Throughout the root canal procedure (continuous observation)

    Patient discomfort will be assessed by a trained observer (blinded to group allocation) who will record the presence or absence of 8 specific behavioral signs of distress during the procedure: (1) eye squeezing, (2) sweating (forehead or upper lip), (3) muscle tension (hand clenching, leg movements), (4) withdrawal/attempts to avoid treatment, (5) groaning, (6) crying, (7) breath-holding, (8) increased saliva production. The total score (0-8) is calculated by summing the number of observed signs. This total score is further categorized as mild (0-2), moderate (3-4), severe (5-6), or very severe (7-8) for analysis.

Other outcomes

  1. Gag-Related Pause Ratio

    Time frame: Throughout the root canal procedure (continuous timing)

    Treatment efficiency will be assessed by measuring the duration of pauses directly caused by the patient's gag reflex. The total treatment time (from rubber dam placement to final obturation) and the cumulative time of all gag-related pauses will be timed using a stopwatch. The primary metric is the pause ratio, calculated as: (Total pause time due to gagging / Total treatment time) × 100.

  2. Salivary Alpha-Amylase Level Change

    Time frame: Immediately before and immediately after the root canal procedure (two time points)

    Stress levels will be objectively assessed by measuring salivary alpha-amylase (sAA) activity. Unstimulated whole saliva samples (1-2 mL) are collected from each patient at two time points: immediately before the start of the dental procedure (T0, baseline) and immediately after the completion of root canal treatment (T1). Samples are stored at -80°C until analysis. sAA levels are measured using a commercially available ELISA kit specific for human AMY1. Optical density is read at 450 nm using a spectrophotometer, and concentrations are determined by comparison to a standard curve. The primary outcome is the change in sAA level (Δ-sAA = T1 - T0), which represents the stress response to the treatment.

Sponsors and collaborators

Lead sponsor

Beyhan Başkan

Other

Registry information

Official study 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

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Mar 25, 2026
Registry last updated
Apr 9, 2026

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

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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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