Effect of Zinc Oxide Ointment on Recurrent Aphthous Stomatitis (ZO-RAS)

April 29, 2026 updated by: Esraa hamdy, Faculty of Dental Medicine for Girls

Evaluation of Zinc Oxide Ointment in Treatment of Recurrent Aphthous Stomatitis

This randomized placebo-controlled trial evaluated the effectiveness of zinc oxide ointment in the treatment of recurrent aphthous stomatitis (RAS). The study included 100 patients randomly assigned to receive either zinc oxide ointment or a placebo, applied three times daily for six days. Pain intensity was measured using a visual analogue scale (VAS), and oral health-related quality of life was assessed using OHIP-14 at baseline and on days 1, 3, and 6.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

This randomized, placebo-controlled clinical trial investigated the efficacy of topical zinc oxide ointment in the management of recurrent aphthous stomatitis (RAS). A total of 100 participants diagnosed with RAS were enrolled and randomly assigned in equal proportions to either the intervention group receiving zinc oxide ointment or the control group receiving a placebo formulation. The study medication was applied topically three times daily for a duration of six consecutive days.

Clinical outcomes were assessed at baseline and on days 1, 3, and 6 post-treatment initiation. Pain intensity was evaluated using a visual analogue scale (VAS), while oral health-related quality of life was measured using the Oral Health Impact Profile (OHIP-14). Additional clinical observation included assessment of ulcer size and surrounding erythematous halo.

Study Type

Interventional

Enrollment (Actual)

100

Phase

  • Phase 4

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

  • Egypt
    • Cairo Governorate
      • Cairo, Cairo Governorate, Egypt, 11651
        • Faculty of Dental Medicine for Girls ,Al-Azhar university

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

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • -Systemically healthy subjects suffering from minor oral RAS.
  • Patients of both sexes, aged 16-45 years (to avoid the potential effects of age on healing).
  • Participants had not received any treatment for the ulcers before being included in the study and had no active periodontitis.
  • Ulcers are of a duration of less than 48 hours.

Exclusion Criteria:

  • -Participants with removable prosthetic or orthodontic appliances (to avoid potential effects on healing).
  • Tobacco chewers, smokers or alcoholics.
  • Pregnant or lactating females.
  • Patients who had previously or are presently taking medications that could affect events associated with the healing process (erg, corticosteroids, oral antidiabetics, non-steroidal anti-inflammatory drugs, immune-modulating agents).

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Znic Oxide Ointment group
Participants administrated Zinc Oxide Ointment 3 times for 7days. Participants instructed to apply ointment after drinking and eating.
Drug: zinc oxide
zinc oxide ointment that was formulated as in a polyethylene glycol base. The prepared ointment was evaluated for organoleptic properties such as odor, color, pH, smoothness, and spread ability
Other Names:
  • Medicated ointment
Placebo Comparator: Placebo
Placebo ointment was administered by this group; it was prepared the same as the test ointment, without zinc oxide.
Drug: Placabo
A topical placebo ointment that was prepared the same as the test ointment without zinc oxide.
Other Names:
  • Ointment without Zinc Oxide

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Visual analog scale
Time Frame: Before treatment ,Day 1,Day 3 and Day 6
A Visual Analog Scale (VAS) is a subjective, validated, 100mm (or 10cm) straight-line tool used in healthcare to measure pain intensity, fatigue, or other sensations. Patients mark their sensation level between "no pain" (0) and "worst pain imaginable" (100). It is highly sensitive for tracking changes in symptoms over time
Before treatment ,Day 1,Day 3 and Day 6

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diameter of the ulcer
Time Frame: Day before treatment,1st day,3rd day and 6th day
Measurement of erythematous halo diameter and whitish base
Day before treatment,1st day,3rd day and 6th day
OHIP-14
Time Frame: At day 6
Oral health impact 14 questionnaire Secondary outcome: Oral health-related quality of life assessed using the validated Oral Health Impact Profile-14 (OHIP-14), with scores ranging from 0 to 56, where higher scores indicate poorer quality of life.
At day 6

Collaborators and Investigators

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

Sponsor

Faculty of Dental Medicine for Girls

Collaborators

Cairo University

Investigators

  • Principal Investigator: Naglaa M. El-Wakeel, PhD, Al Azhar University for girls

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

June 30, 2025

Primary Completion (Actual)

January 30, 2026

Study Completion (Actual)

March 30, 2026

Study Registration Dates

First Submitted

April 22, 2026

First Submitted That Met QC Criteria

April 29, 2026

First Posted (Actual)

May 4, 2026

Study Record Updates

Last Update Posted (Actual)

May 4, 2026

Last Update Submitted That Met QC Criteria

April 29, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OMDR_105_1q

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

This study investigated whether zinc oxide (ZnO) ointment can help reduce pain and improve healing in patients with recurrent aphthous ulcers (mouth ulcers). One hundred participants were divided into two groups: one received ZnO ointment and the other received a placebo. The treatment was applied three times daily for six days. Pain levels and oral health impact were measured before and after treatment. The results showed that ZnO ointment helped reduce pain faster in the early days compared to placebo, but there was no significant difference in overall quality of life after six days.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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.

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