Comparing benzoin resin and Coe-Pak for gum healing after pigmentation removal surgery
| ISRCTN | ISRCTN69063431 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN69063431 |
| ClinicalTrials.gov (NCT) | Nil known |
| Clinical Trials Information System (CTIS) | Nil known |
| Protocol serial number | Nil known |
| Sponsor | Damascus University |
| Funder | Damascus University |
- Submission date
- 05/08/2025
- Registration date
- 08/08/2025
- Last edited
- 08/08/2025
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Oral Health
Plain English summary of protocol
Background and study aims
This clinical study investigates whether a natural product called benzoin resin tincture can improve healing and reduce pain after a cosmetic dental procedure known as gingival depigmentation, which removes dark pigmentation from the gums. While this pigmentation is harmless, it can be a cosmetic concern for individuals with a prominent smile. The standard post-surgical dressing, Coe-Pak, protects the wound but does not actively support healing. Benzoin resin, on the other hand, has known healing, anti-inflammatory, and antimicrobial properties.
Who can participate?
Healthy adults aged 18–40 years with natural gum pigmentation.
What does the study involve?
Participants underwent gum depigmentation on both sides of the upper jaw. One side was treated with Coe-Pak, and the other with benzoin resin tincture. Researchers assessed healing, pain levels, and recovery over four weeks.
What are the possible benefits and risks of participating?
Participants will help to determine whether benzoin resin tincture offers a better, low-cost alternative to traditional periodontal dressings.
Participants may experience temporary pain, swelling, or mild bleeding after surgery, similar to standard gum procedures. There is a small risk of infection or allergic reaction to the dressing materials, which will be managed promptly if it occurs.
Where is the study run from?
The Faculty of Dentistry, Damascus University, Syria.
When is the study starting and how long is it expected to run for?
April 2024 to June 2025
Who is funding the study?
The Faculty of Dentistry, Damascus University, Syria.
Who is the main contact?
MHD Bahaa Aldin Alhaffar, bhaa.alhafar@gmail.com
Contact information
Public, Scientific, Principal investigator
Damascus University
Damascus
00000
Syria
 ORCID ID |
0009-0005-3500-9456 |
|---|---|
| Phone | +963932985177 |
| tala.alkhin98@damascusuniversity.edu.sy |
Scientific
Damascus University
Damascus
00000
Syria
| ORCID ID |
0000-0002-9147-189X |
|---|---|
| Phone | +963944216062 |
| bhaa.alhafar@gmail.com |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | Randomized controlled split-mouth design trial |
| Secondary study design | Randomised controlled trial |
| Study type | Participant information sheet |
| Scientific title | Benzoin resin tincture versus Coe-Pak for postoperative healing after gingival depigmentation: a randomized controlled split-mouth clinical trial |
| Study objectives | To evaluate the clinical effectiveness of benzoin resin tincture compared to Coe-Pak as a postoperative dressing following surgical gingival depigmentation, with a specific focus on wound healing, epithelialization, and postoperative pain. |
| Ethics approval(s) |
Approved 15/04/2024, Higher Committee for Scientific Research at Damascus University (Almazzah, Damascus, 00000, Syria; +963-11-33923192; info@damascusuniversity.edu.sy), ref: n/a162536 |
| Health condition(s) or problem(s) studied | Physiological gingival pigmentation Postoperative healing after depigmentation surgery |
| Intervention | Healthy adult participants aged 18–40 years with bilateral physiological gingival pigmentation in the upper anterior region were enrolled after providing written informed consent. Each participant underwent gingival depigmentation surgery on both sides of the upper front gums using a standard scalpel technique. In a split-mouth randomised design, one side was allocated to the test intervention and the other to the control. Allocation was determined by a simple coin toss before surgery. • Test intervention: Application of benzoin resin tincture (Myzotect) to the depigmented site using a sterile microbrush, forming a protective film. No reapplication was required unless dislodgement occurred. • Control intervention: Placement of Coe-Pak periodontal dressing over the depigmented site, left in place for 7 days unless dislodged. Participants were reviewed on days 1, 2, 3, 5, and 7, and at weeks 2, 3, and 4 postoperatively. The total observation period was 4 weeks per participant, with both clinical (epithelialization index, wound healing index) and patient-reported (pain via VAS, analgesic use) outcomes recorded. |
| Intervention type | Procedure/Surgery |
| Primary outcome measure(s) |
Epithelialization index measured using the degree of epithelial coverage at the surgical site (Grade 0–3), weekly for 4 weeks postoperatively |
| Key secondary outcome measure(s) |
1. Healing measured using the Wound Healing Index (H1–H5) assessed weekly for 4 weeks |
| Completion date | 01/06/2025 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 40 Years |
| Sex | All |
| Target sample size at registration | 12 |
| Total final enrolment | 12 |
| Key inclusion criteria | 1. Aged 18–40 years 2. Presence of physiological melanin pigmentation in the upper anterior gingiva (Hedin index 3 or 4) 3. Confirmed absence of systemic or pathological causes of pigmentation 4. Good general health (ASA I) 5. Adequate width and thickness of attached gingiva 6. No signs of active periodontal disease 7. No prior surgical intervention in the target area 8. Informed consent provided and willingness to comply with follow-up visits |
| Key exclusion criteria | 1. Smoking or tobacco use 2. Alcohol abuse 3. Pregnancy or lactation 4. Use of anti-inflammatory, immunosuppressive, or photosensitizing medications 5. Systemic diseases affecting healing (e.g. uncontrolled diabetes) 6. History of radiation therapy 7. Known allergy to any component of benzoin resin tincture or Coe-Pak dressing |
| Date of first enrolment | 01/06/2024 |
| Date of final enrolment | 01/02/2025 |
Locations
Countries of recruitment
- Syria
Study participating centre
Damascus
00000
Syria
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | The anonymised aggregate datasets and analysis results generated during and/or analysed during the current study are/will be available upon request from MHD Bahaa Aldin Alhaffar, bhaa.alhafar@gmail.com. There is no plan to share individual participant data (IPD) due to ethical restrictions and the small sample size. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
05/08/2025: Study's existence confirmed by the Higher Committee for Scientific Research at Damascus University.
