The goal of this randomized clinical trial is to evaluate whether cyanoacrylate tissue adhesive can improve postoperative outcomes compared with conventional silk sutures in patients undergoing surgical removal of impacted mandibular third molars.

The main questions it aims to answer is: Is there a difference in wound healing support, soft-tissue conditions, and microbiological outcomes at the surgical site of impacted mandibular third molar extraction between closure with conventional sutures and cyanoacrylate tissue adhesive? Researchers will compare cyanoacrylate tissue adhesive with conventional silk sutures to determine whether the adhesive provides superior postoperative recovery and periodontal outcomes.

Participants will:

• Undergo surgical extraction of an impacted mandibular third molar.
• Receive wound closure using either cyanoacrylate tissue adhesive or conventional silk sutures.
• Be followed postoperatively for assessment of pain, swelling, trismus, soft-tissue healing, and periodontal measurements at specified time points.

Surgical removal of impacted mandibular third molars is one of the most common procedures in dental practice. Following surgery, conventional wound closure using sutures is widely employed to support healing. However, this method has several limitations, including difficult surgical access to the posterior oral cavity, tissue trauma during suturing, plaque accumulation around the suture site, and the need for suture removal after surgery. These drawbacks create a need for alternative wound-closure approaches. Recently, the development of biomaterials, particularly cyanoacrylate tissue adhesives has introduced a new strategy that may improve healing and reduce postoperative complications.

Cyanoacrylate tissue adhesives have been reported to possess favorable biological properties, including antibacterial activity, hemostatic capability, biodegradability, and biocompatibility with living tissues. Various cyanoacrylate derivatives have been investigated, ranging from methyl, ethyl, and propyl to butyl and octyl cyanoacrylate, among which butyl and octyl forms demonstrate the most favorable clinical performance.

In oral surgery, cyanoacrylate has been recognized as a useful alternative due to its ability to shorten operative time, reduce postoperative pain, and eliminate the need for suture removal after healing. Lascaz Netto and Macedo (1986) evaluated wound healing in patients using cyanoacrylate for gingival graft fixation and reported significantly reduced surgical time with normal postoperative recovery. Cyanoacrylate adhesives have also been applied for multiple clinical purposes, including periodontal dressing, closure of sinus membrane perforations, fixation of bone fragments in fracture surgery, and peripheral nerve repair. In addition, cyanoacrylate has been proposed for wound closure via primary healing and, more recently, for protection of wounds healing by secondary intention.

Although cyanoacrylate tissue adhesives have been widely studied and applied in medicine, limited evidence exists regarding their effectiveness in supporting soft-tissue healing and their impact on the local oral microbiological environment. Moreover, few studies have directly compared tissue adhesives with conventional suturing across multiple bacterial species using modern analytical techniques. Therefore, this study was conducted to evaluate the soft-tissue healing support provided by cyanoacrylate tissue adhesive compared with traditional sutures through three aspects: common postoperative complications (pain, swelling, and trismus), the rate of soft-tissue healing, and changes in the microbiological profile at the surgical site.

Inclusion Criteria:

• Patients aged 18 years or older.
• Patients presenting with bilateral mandibular third molars indicated for extraction, with the same level of surgical difficulty according to the Pell-Gregory classification, and an angulation difference between the two teeth not exceeding 15° according to the Winter classification on panoramic radiographs.
• No use of local or systemic antibiotics within 2 weeks prior to surgery.
• Absence of serious systemic diseases such as coagulation disorders or uncontrolled diabetes, and no acute infection at the extraction site.
• Patients who agree to participate in the study after receiving clear explanation and counseling.

Exclusion Criteria:

• Patients who are uncooperative in providing necessary information or who decline to continue participation in the study.
• A difference in surgical duration between the two sides exceeding 12 minutes, or the occurrence of intraoperative complications.
• Patients with known hypersensitivity or allergy to any materials used in the study, such as lidocaine local anesthetic, cyanoacrylate adhesive, or suture materials.

Postoperative outcome assessments are performed by an independent examiner who is blinded to the wound-closure method. Participants and surgeons are not blinded due to the nature of the surgical interventions. Allocation information is concealed during clinical measurements and data analysis.