Essential Oil Mouthwash - Oral Hygiene

NCT07887074 | Completed DMC

• 1 other identifier: ANHRF113-46
• Study Type: interventional
• Target: 150
• Locations: 1 country
• Sites: 1

Brief Summary

Background Inadequate oral health can further compromise general health, particularly in elderly patients who are more susceptible to tooth loss, periodontal disease, and oral infections. These conditions can impair nutrition and overall well-being and are associated with increased risks of systemic diseases, underscoring the critical need for effective oral care in this population. Essential oils and various plant extracts have attracted considerable attention as potential natural medicinal products due to their proven antibacterial, antifungal, antiviral, and antioxidant properties. However, the precise effects and underlying mechanisms through which essential oil mouthwashes promote oral health remain incompletely understood. Objective This study aims to evaluate the potential of a mouthwash formulated with a blend of tea tree, lemon, and bay laurel essential oils, which have long been recognized for their medicinal properties in alleviating inflammatory signs of intraoral mucosa and promoting both oral and gingival health, in comparison with/ without alcohol-based mouthwashes. Methods One hundred five community-dwelling elderly individuals were randomly assigned to one of three groups and used a designated mouthwash for oral care over 21 days. The study groups were as follows:

1. 1.Essential oils mouthwash (tea tree, lemon, and bay laurel).
2. 2.Chlorhexidine alcohol-free mouthwash.
3. 3.Povidone-iodine alcohol-free mouthwash. Participants were instructed to use the assigned mouthwash for oral hygiene at least twice daily, in the morning and evening. Saliva samples were collected on day 1 (before using the mouthwash) and on day 21 to analyze oral microbiota and inflammation markers and assess oral health and the incidence of upper respiratory tract infections.

Conditions

Oral Hygiene, Oral Health; Dental Plaque; Respiratory Tract Infections (RTI)

Keywords

essential oil; tea tree; mouthwash; oral health; respiratory infection

Outcome Measures

Primary Outcomes (3)

• Change in Oral Health Assessment Tool (OHAT) Score

  Overall oral health status assessed by a trained assessor blinded to group allocation using the Oral Health Assessment Tool, which comprises eight domains (lips, tongue, gums and oral tissues, saliva, natural teeth, dentures, oral cleanliness, and dental pain), each scored 0-2. Total score ranges from 0 to 16; higher scores indicate poorer oral health.

  Baseline (Day 1) and Day 21

• Change in Plaque Index Score

  Dental plaque accumulation assessed using a plaque-disclosing agent and scored by a trained assessor blinded to group allocation according to the Silness and Löe criteria: 0 = no plaque, 1 = thin film of plaque along the gingival margin, 2 = visible plaque accumulation, 3 = abundant plaque accumulation. Higher scores indicate greater plaque accumulation.

  Baseline (Day 1) and Day 21

• Change in Halitosis Consequences Inventory (ICH) Score

  Halitosis-related quality of life assessed using the 18-item self-report Halitosis Consequences Inventory, with each item rated dichotomously for the presence (1) or absence (0) of the corresponding behavioral, emotional, or social consequence of bad breath. Total score ranges from 0 to 18; higher scores indicate greater perceived impact of halitosis.

  Baseline (Day 1) and Day 21

Secondary Outcomes (6)

• Change in Stomatitis Index Score

  Baseline (Day 1) and Day 21

• Change in Self-Perceived Oral Health Status

  Baseline (Day 1) and Day 21

• Change in Geriatric Oral Health Assessment Index (GOHAI) Score

  Baseline (Day 1) and Day 21

• Incidence of Upper Respiratory Tract Symptoms

  Baseline (Day 1) and Day 21

• Change in Salivary Oral Microbiota Composition

  Baseline (Day 1) and Day 21

Study Arms (3)

Essential oil mouthwash

EXPERIMENTAL

Participants rinse with 30 mL of an alcohol-free mouthwash containing a blend of tea tree, lemon, and bay laurel essential oils for at least 30 seconds twice daily (morning and evening) after toothbrushing for 21 days.

Other: Essential oil mouthwash

Chlorhexidine Mouthwash

ACTIVE COMPARATOR

Community-dwelling older adults using an alcohol-free chlorhexidine mouthwash twice daily for 21 days.

Other: Chlorhexidine gluconate alcohol-free mouthwash

Povidone-Iodine Mouthwash

ACTIVE COMPARATOR

Community-dwelling older adults using an alcohol-free povidone-iodine mouthwash twice daily for 21 days.

Other: Povidone-iodine alcohol-free mouthwash

Interventions

Essential oil mouthwash OTHER

Participants rinse with 30 mL of an alcohol-free mouthwash containing a blend of tea tree, lemon, and bay laurel essential oils for at least 30 seconds twice daily (morning and evening) after toothbrushing for 21 days.

Essential oil mouthwash

Chlorhexidine gluconate alcohol-free mouthwash OTHER

Participants rinse with 30 mL of an alcohol-free chlorhexidine gluconate 2.0 mg/mL mouthwash for at least 30 seconds twice daily (morning and evening) after toothbrushing for 21 days.

Chlorhexidine Mouthwash

Povidone-iodine alcohol-free mouthwash OTHER

Participants rinse with 30 mL of an alcohol-free povidone-iodine mouthwash (available iodine 1 mg/mL) for at least 30 seconds twice daily (morning and evening) after toothbrushing for 21 days.

Povidone-Iodine Mouthwash

Eligibility Criteria

• Age: 65 Years - 99 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Aged 65 years or older.
• Able to communicate verbally.
• No history of asthma, eczema, or allergy to flowers or plants.
• No known hypersensitivity to essential oils, chlorhexidine, or cetylpyridinium chloride.
• No immunocompromising conditions.
• No current use of antihistamines, immunosuppressants, biologic agents, disease-modifying antirheumatic drugs (DMARDs), or corticosteroids that may affect inflammatory responses.
• Willing to participate in the study.
• No use of essential oils or complementary medicine during the past week.

You may not qualify if:

• Younger than 65 years of age.
• Observation period of less than 30 days.
• Major immunodeficiency disorder.
• Dental treatment for periodontal disease or oral infection during the study period.
• History of hypersensitivity to essential oils, chlorhexidine, or povidone-iodine.

Sponsors & Collaborators

• China Medical University, Taiwan: lead

Study Sites (1)

An Nan Hospital, China Medical University, Tainan, Taiwan.

Tainan, 709, Taiwan

Location

MeSH Terms

Conditions

Dental Plaque; Respiratory Tract Infections

Interventions

chlorhexidine gluconate; Ethanol; Povidone-Iodine

Condition Hierarchy (Ancestors)

Dental Deposits; Tooth Diseases; Stomatognathic Diseases; Infections; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Alcohols; Organic Chemicals; Iodophors; Iodine Compounds; Inorganic Chemicals; Polyvinyls; Vinyl Compounds; Alkenes; Hydrocarbons, Acyclic; Hydrocarbons; Povidone; Pyrrolidinones; Pyrrolidines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Plastics; Polymers; Macromolecular Substances; Biomedical and Dental Materials; Manufactured Materials; Technology, Industry, and Agriculture

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Masking Details: Blocked randomization using a computer-generated list was performed because of the small sample size. One hundred fifty patients were recruited and allocated a ratio of 1:1:1 into one of the following three groups (n = 50 per group). Group A received mouthwash with essential oils (tea tree, lemon, and bay laurel). Group B received Chlorhexidine alcohol-free mouthwash, and Group C received Povidone-iodine alcohol-free mouthwash. A computer-generated list of random numbers using block randomization procedures was utilized to allocate participants.
• Purpose: SUPPORTIVE CARE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: The trial was conducted from January 1, 2025, to December 31, 2025, in the neighboring community areas of a regional teaching hospital in southern Taiwan. This study employed an examiner-blind, three-armed, randomized controlled trial design. Blocked randomization using a computer-generated list was performed because of the small sample size. One hundred fifty patients were recruited and allocated a ratio of 1:1:1 into one of the following three groups (n = 50 per group). Group A received mouthwash with essential oils (tea tree, lemon, and bay laurel). Group B received Chlorhexidine alcohol-free mouthwash, and Group C received Povidone-iodine alcohol-free mouthwash. A computer-generated list of random numbers using block randomization procedures was utilized to allocate participants.

Study Record Dates

• First Submitted: October 15, 2026
• First Posted: October 21, 2026
• Study Start: April 12, 2025
• Primary Completion: February 11, 2026
• Study Completion: October 12, 2026
• Last Updated: October 21, 2026

Record last verified: 2025-02

Data Sharing

• IPD Sharing: Will not share

Locations

TW (1)