1. ABSTRACT This study is a randomized controlled trial comparing the clinical efficacy and safety of four different flap closure techniques in reducing postoperative morbidity (pain, swelling, trismus, wound healing) and improving patient quality of life (GOHAI) following impacted mandibular third molar extraction. The methods include conventional suturing, sutureless technique, surgical drain, and cyanoacrylate tissue adhesive, which are commonly used in oral surgery practice. The study aims to scientifically evaluate the effects of each method on patients and to determine the most appropriate clinical approach.

2. INTRODUCTION Impacted mandibular third molar extraction is a commonly performed surgical procedure. Postoperative morbidity following this procedure can negatively affect patient satisfaction and quality of life. The rationale for this study is to objectively examine the role of flap closure techniques, which are an integral part of the surgical procedure, on these morbidities. The methods investigated in this research were selected due to their potential impact on wound healing and postoperative comfort.

3. PHYSICAL AND CHEMICAL CHARACTERISTICS OF THE METHODS USED

Surgical Drain Application: A biocompatible, sterile plastic tube used to drain accumulated blood and other fluids from the tissues.

Conventional Suturing Technique: Wound edges are approximated using 3/0 braided, non-absorbable silk suture (Doğsan®, Turkey). Silk suture is biologically inert and provides strong tensile strength.

Cyanoacrylate (PeriAcryl®90 High Viscosity Dental Cyanoacrylate): A cyanoacrylate-based medical tissue adhesive. Its rapid polymerization allows effective closure of wound edges.

Sutureless Technique: No material is used in this method; the wound is left to heal by secondary intention.

4. NON-CLINICAL STUDIES This study does not involve any investigational product (drug) with systemic pharmacological or toxicological effects. Therefore, no evaluation of pharmacological, toxicological, or pharmacokinetic studies in animals is relevant in this section.

5. EFFECTS ON HUMANS AND SAFETY-EFFICACY ASSESSMENT All four flap closure techniques are commonly used in oral surgery and have well-known safety profiles.

Conventional Sutures: May cause postoperative pain, swelling, and trismus. The most common adverse events are infection and bleeding.

Cyanoacrylate: Literature reports indicate it may accelerate wound healing and reduce pain. Potential adverse reactions include local irritation or allergic responses.

Surgical Drain: May contribute to wound healing by reducing edema and hematoma formation. Possible adverse events include discomfort at the incision site or infection.

Sutureless Technique: May be associated with increased postoperative pain and swelling. Wound healing may take longer compared to other methods.

This study is designed to compare the safety and efficacy of these methods using a randomized controlled methodology and to determine which method is superior in terms of patient quality of life and morbidity.

6. MARKETING EXPERIENCE The medical materials used in this study, including cyanoacrylate (PeriAcryl®90) and silk sutures (Doğsan®), are commercially available products approved by relevant regulatory authorities. None of the products have been withdrawn from the market. PeriAcryl®90 has been registered by Intertek, an MDSAP-certified auditing organization, in compliance with ISO 13485:2016 requirements.

7. SUMMARY OF DATA AND INVESTIGATOR GUIDE As the aim of this study is to compare surgical methods, it is essential that investigators understand the known benefit-risk profile of each technique. The health and safety of volunteers are the top priority.

Potential Risks and Adverse Reactions:

Expected postoperative morbidities such as pain, swelling, and trismus, as well as surgery-specific risks like infection, bleeding, and rarely nerve injury.

Precautions:

All surgical procedures will be performed according to a standardized protocol by experienced surgeons.

Volunteers will be provided with a full and understandable informed consent form detailing all risks and expectations related to the postoperative period.

Regular follow-up visits are scheduled on the 2nd and 7th days for early detection and management of potential complications.

Emergency Management:

In the event of a serious adverse event, such as life-threatening conditions or permanent disability, the protocol procedures will be immediately implemented and reported to the Turkish Medicines and Medical Devices Agency (TITCK).

Inclusion Criteria:

• Patients aged 18-40 years.
• Patients with no systemic diseases (ASA I).
• Patients with impacted mandibular third molars indicated for extraction, with bone and/or mucosal retention, in similar positions (Pell & Gregory Class 2, Position B; Winter classification vertical or mesioangular).

Exclusion Criteria:

• Patients classified as ASA II, III, or IV.
• Known allergy to anesthetic solutions.
• Allergy to acrylate.
• Pregnant or breastfeeding women.
• Individuals with tobacco use ≥10 cigarettes/day.
• Alcohol users.
• Patients using antiplatelet agents.
• Patients using anticoagulants.
• Patients with coagulation disorders.
• Patients with immunosuppressive diseases or receiving immunosuppressive therapy.

Patients with acute pain or local infection at the surgical site.

De-identified individual participant data from this study will be made available upon reasonable request to the corresponding author after publication of the primary results. Data sharing will be for research purposes only and will require a signed data sharing agreement to ensure participant privacy and confidentiality

Outcome assessors evaluating postoperative morbidity (pain, swelling, trismus, wound healing) and patient quality of life (GOHAI) are blinded to the flap closure technique assigned to each participant. Surgeons and participants are not blinded due to the nature of the surgical interventions.