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

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

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Gag Reflex
• Intervention / Treatment: Device: Custom-Made Silicone Earplug

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Kahramanmaraş, Turkey (Türkiye), 46140
    • Kahramanmaraş Sütçü İmam Universty

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental Group; Patients 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.	Device: Custom-Made Silicone Earplug; 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.
No Intervention: Control Group; Patients 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 the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gag Reflex Severity	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).	At the time of the root canal procedure (single time point during the most challenging part of treatment)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Behavioral Response Score	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.	Throughout the root canal procedure (continuous observation)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gag-Related Pause Ratio	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.	Throughout the root canal procedure (continuous timing)
Salivary Alpha-Amylase Level Change	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.	Immediately before and immediately after the root canal procedure (two time points)

Collaborators and Investigators

• Sponsor: Beyhan Başkan

Publications and helpful links

General Publications

• Rosted P, Bundgaard M, Fiske J, Pedersen AM. The use of acupuncture in controlling the gag reflex in patients requiring an upper alginate impression: an audit. Br Dent J. 2006 Dec 9;201(11):721-5; discussion 715. doi: 10.1038/sj.bdj.4814305.
• Yoshida H, Ayuse T, Ishizaka S, Ishitobi S, Nogami T, Oi K. Management of exaggerated gag reflex using intravenous sedation in prosthodontic treatment. Tohoku J Exp Med. 2007 Aug;212(4):373-8. doi: 10.1620/tjem.212.373.
• Eitner S, Wichmann M, Holst S. "Hypnopuncture"--a dental-emergency treatment concept for patients with a distinctive gag reflex. Int J Clin Exp Hypn. 2005 Jan;53(1):60-73. doi: 10.1080/00207140490914243.
• Garg R, Singhal A, Agrawal K, Agrawal N. Managing endodontic patients with severe gag reflex by glossopharyngeal nerve block technique. J Endod. 2014 Sep;40(9):1498-500. doi: 10.1016/j.joen.2014.01.028. Epub 2014 Mar 6.

Study record dates

Study Major Dates

• Study Start (Actual): May 12, 2025
• Primary Completion (Actual): February 5, 2026
• Study Completion (Estimated): April 30, 2026

Study Registration Dates

• First Submitted: March 19, 2026
• First Submitted That Met QC Criteria: March 19, 2026
• First Posted (Actual): March 25, 2026

Study Record Updates

• Last Update Posted (Actual): April 9, 2026
• Last Update Submitted That Met QC Criteria: April 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Randomized Controlled Trial; Root Canal Treatment; Salivary Alpha-Amylase
• Additional Relevant MeSH Terms: Signs and Symptoms, Digestive; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Gagging
• Other Study ID Numbers: HRÜ/24.09.54

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