Comparison Between Liquid Fibrin and Soft Laser Effects on Healing and Relapse After Lip Repositioning Surgery

NCT07532161 | Recruiting

• 1 other identifier: UDDS-Perio-2026-02
• Study Type: interventional
• Target: 22
• Locations: 1 country
• Sites: 1

Brief Summary

A gummy smile can negatively affect a patient's self-confidence and satisfaction with their appearance, leading many individuals to seek effective esthetic solutions. The etiology of this condition varies and may include vertical maxillary excess, short upper lip, hyperactive upper lip, gingival enlargement, or altered passive eruption. Lip Repositioning Surgery is one of the minimally invasive esthetic surgical procedures used to reduce the amount of gingival display during smiling. Despite its effectiveness, this surgery may be associated with challenges such as pain, swelling, delayed wound healing, and the possibility of postoperative relapse over time, which could compromise both esthetic and functional outcomes. To overcome these challenges and enhance surgical outcomes, adjunctive techniques have been introduced to promote healing and determine whether enhancing the biological healing process can reduce the rate of relapse after LRS. Among the most prominent of these are Injectable Platelet-Rich Fibrin (i-PRF) and Low-Level Laser Therapy (LLLT).

Conditions

Gummy Smile

Keywords

Excessive gingival display; Gummy smile; Lip Repositioning Surgery; Injectable Platelet-Rich Fibrin (i-PRF); Liquid Platelet-Rich Fibrin; Low-Level Laser Therapy (LLLT); Wound healing; Postoperative relapse; Gingival display reduction; Esthetic dentistry

Outcome Measures

Primary Outcomes (2)

• Gingival display (mm)

  Measured in millimeters from the lowest point of the upper lip vermilion border to the free gingival margin of the maxillary teeth (from right second premolar to left second premolar) during full smile.

  Baseline and 1, 3 and 6 months postoperatively

• Wound Healing Index

  Wound healing will be assessed using the Wound Healing Index (Huang, Neiva, and Wang, 2005). This is a categorical scale with scores ranging from 1 to 3: 1. = poor healing (significant gingival swelling or redness, severe patient discomfort, slough formation with suppuration); 2. = good healing (mild gingival swelling or redness, mild patient discomfort, slough formation without suppuration); 3. = complete healing (no gingival swelling, redness, suppuration, or patient discomfort, and no slough formation). Higher scores indicate better healing outcomes.

  weekly for 4 weeks postoperatively

Secondary Outcomes (7)

• Postoperative Pain (VAS 0-100)

  Days 1-7 postoperatively

• Postoperative Edema/Swelling

  Day 3 postoperatively

• Esthetic Satisfaction (VAS 0-100)

  6 months postoperatively

• Upper Lip External Length

  Baseline, 1,3 and 6 months postoperatively

• Upper Lip Internal Length

  Baseline, 1, 3 and 6 months postoperatively

Study Arms (2)

Liquid Platelet-Rich Fibrin group

EXPERIMENTAL

This group will consist of 11 patients presenting with excessive gingival display due to upper lip hypermobility. Each patient will undergo lip repositioning surgery, followed by immediate injection of Liquid Platelet-Rich Fibrin after completion of the surgical procedure.

Other: Liquid Platelet-Rich Fibrin group

Low-Level Laser group

EXPERIMENTAL

This group will consist of 11 patients presenting with excessive gingival display due to upper lip hypermobility. Each patient will undergo lip repositioning surgery, followed by immediate application of low-level laser therapy (LLLT) after completion of the surgical procedure and at 3,7,10, and 14 days after surgery.

Other: low-level laser group

Interventions

Liquid Platelet-Rich Fibrin group OTHER

A partial thickness elliptical mucogingival incision was made from the mesial of the central incisor to the mesial of the first molar bilaterally with preservation of the frenulum; vertical height set to twice the excessive gingival display (2:1 ratio), lower margin 1 mm coronal to the mucogingival junction. Epithelium elevated to expose connective tissue (preserving minor salivary glands). Periosteal sutures (4-0 Vicryl, 2-3 per side) placed where connective tissue ≥0.5 mm ; incision edges approximated with simple interrupted 4-0 silk sutures. 20 mL blood collected into additive-free plastic tubes and centrifuged at 300 × g for 5 minutes. The Liquid Platelet-Rich Fibrin layer was aspirated and injected immediately after surgery along incision margins and surrounding tissue at 1 mm depth, multiple points 2-3 mm apart (≈0.1 mL per injection) to achieve homogeneous distribution.

Liquid Platelet-Rich Fibrin group

low-level laser group OTHER

A partial thickness elliptical mucogingival incision was made from the mesial of the central incisor to the mesial of the first molar bilaterally with preservation of the frenulum; vertical height set to twice the excessive gingival display (2:1 ratio), lower margin 1 mm coronal to the mucogingival junction. Epithelium elevated to expose connective tissue (preserving minor salivary glands). Periosteal sutures (4-0 Vicryl, 2-3 per side) placed where connective tissue ≥0.5 mm to ; incision edges approximated with simple interrupted 4-0 silk sutures. low-level laser applied to the surgical site (635nm, 200 mW) as part of the post-surgical treatment and at 3,7,10, and 14 days after surgery.

Low-Level Laser group

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Patients of both genders.
• Patients presenting with a gummy smile in the maxillary anterior region (more than 3 mm) due to upper lip hypermobility.
• Age 18-50 years.
• Systemically healthy individuals, classified as ASA physical status I or II according to the American Society of Anesthesiologists (ASA) classification; that is, patients without systemic disease or with mild, well-controlled systemic conditions.
• Patients with good oral hygiene, defined as an O'Leary Plaque Index ≤ 40%.
• No previous lip repositioning surgery.

You may not qualify if:

• Pregnancy and lactation.
• Individuals with a previous history of receiving facial Botox or filler injections.
• Systemic diseases or conditions that contraindicate the use of local anesthesia.
• Any physical condition that impairs the ability to perform proper oral hygiene measures.
• Patients who are smokers or alcohol consumers.
• Inability or unwillingness to cooperate.
• In adequate width of attached gingiva.
• Vertical maxillary excess (moderate to severe) requiring orthognathic intervention.
• Short upper lip
• Gingival display primarily caused by altered passive eruption requiring crown lengthening.

Sponsors & Collaborators

• Damascus University: lead

Study Sites (1)

Faculty of Dentistry, Damascus university , Syria.

Damascus, Rif-dimashq Governorate, Syria

RECRUITING

Related Publications (8)

• Miron RJ, Gruber R, Farshidfar N, Sculean A, Zhang Y. Ten years of injectable platelet-rich fibrin. Periodontol 2000. 2024 Feb;94(1):92-113. doi: 10.1111/prd.12538. Epub 2023 Nov 30.

  PMID: 38037213 BACKGROUND

• Alammar A, Heshmeh O, Mounajjed R, Goodson M, Hamadah O. A comparison between modified and conventional surgical techniques for surgical lip repositioning in the management of the gummy smile. J Esthet Restor Dent. 2018 Nov;30(6):523-531. doi: 10.1111/jerd.12433. Epub 2018 Nov 9.

  PMID: 30412347 BACKGROUND

• Farshidfar N, Amiri MA, Estrin NE, Ahmad P, Sculean A, Zhang Y, Miron RJ. Platelet-rich plasma (PRP) versus injectable platelet-rich fibrin (i-PRF): A systematic review across all fields of medicine. Periodontol 2000. 2025 Mar 24. doi: 10.1111/prd.12626. Online ahead of print.

  PMID: 40125556 BACKGROUND

• Sun G, Tuner J. Low-level laser therapy in dentistry. Dent Clin North Am. 2004 Oct;48(4):1061-76, viii. doi: 10.1016/j.cden.2004.05.004.

  PMID: 15464564 BACKGROUND

• Tawfik OK, El-Nahass HE, Shipman P, Looney SW, Cutler CW, Brunner M. Lip repositioning for the treatment of excess gingival display: A systematic review. J Esthet Restor Dent. 2018 Mar;30(2):101-112. doi: 10.1111/jerd.12352. Epub 2017 Nov 27.

  PMID: 29193632 BACKGROUND

• AlJasser RN. A Modified Approach in Lip Repositioning Surgery for Excessive Gingival Display to Minimize Post-Surgical Relapse: A Randomized Controlled Clinical Trial. Diagnostics (Basel). 2023 Feb 14;13(4):716. doi: 10.3390/diagnostics13040716.

  PMID: 36832213 BACKGROUND

• Tjan AH, Miller GD, The JG. Some esthetic factors in a smile. J Prosthet Dent. 1984 Jan;51(1):24-8. doi: 10.1016/s0022-3913(84)80097-9.

  PMID: 6583388 BACKGROUND

• Robbins JW. Differential diagnosis and treatment of excess gingival display. Pract Periodontics Aesthet Dent. 1999 Mar;11(2):265-72; quiz 273.

  PMID: 10321231 BACKGROUND

Study Officials

• Tarek Qasem, DDS MSc PhD

  Faculty of Dentistry, Damascus university, Syria.

  STUDY DIRECTOR

Central Study Contacts

Tarek Qasem, DDS MSc PhD

CONTACT

+963 933432778; Tarek2.qasem@damascusuniversity.edu.sy

Walaa albarry, DDS

CONTACT

+963 996766302; walaa9.albarry.@damascusuniversity.edu.sy

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Randomized comparative clinical trial with blinded outcome assessment. Outcome assessment was performed by an independent examiner who was blinded to the treatment allocation. Clinical photographs and clinical measurements were coded and evaluated without revealing the group assignment. Statistical analysis was performed using coded data to ensure blinding of the data analyst.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: April 9, 2026
• First Posted: April 15, 2026
• Study Start: April 20, 2026
• Primary Completion (Estimated): January 31, 2027
• Study Completion (Estimated): January 31, 2027
• Last Updated: April 29, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

SY (1)