Antibacterial Effect and Soft Tissue Healing of Chlorhexidine-Coated Polyglactin 910 Sutures After Impacted Lower Third Molar Surgery

Evaluation of Soft Tissue Healing and Antibacterial Efficacy of Chlorhexidine Diacetate-Coated Polyglactin 910 Sutures in the Surgery of Impacted Mandibular Third Molars: A Randomized, Triple-Blind, Split-Mouth Clinical Trial

This study evaluates whether coating Polyglactin 910 sutures with chlorhexidine diacetate (CHX-DA) improves outcomes after the surgical removal of impacted mandibular (lower) third molars (wisdom teeth).

The study is a randomized, triple-blind, split-mouth clinical trial. Eligible participants are patients aged 18 to 35 years who need extraction of two symmetrical impacted lower wisdom teeth of similar difficulty. For each participant, one extraction site is closed with standard Polyglactin 910 sutures and the other site is closed with chlorhexidine diacetate-coated Polyglactin 910 sutures, with the allocation assigned by random draw. Participants, the surgeon, and the outcome assessors are all blinded to which suture is used at each site.

The researchers compare the two suture types on the bacterial load at the surgical wound site and on soft tissue healing. Bacterial load is assessed from gingival crevicular fluid collected at the wound site next to the suture and quantified by viability real-time PCR (vPCR, copies/mL). Soft tissue healing is assessed using the IPR healing scale. Both outcomes are measured on days 3, 5, and 7 after surgery.

The aim is to determine whether the chlorhexidine-coated suture reduces bacterial load at the wound site and improves soft tissue healing compared with the uncoated suture.

Surgical removal of impacted mandibular third molars is a common oral surgery procedure that carries a risk of postoperative complications such as wound infection, delayed healing, pain, and swelling. Sutures used to close the extraction site can act as a surface for bacterial adhesion from the oral cavity, which may increase the risk of infection at the wound.

Antibacterial-coated sutures have been developed to reduce bacterial colonization and support wound healing. While triclosan-coated sutures have been widely studied, there is limited direct evidence on Polyglactin 910 sutures coated with chlorhexidine diacetate (CHX-DA), particularly in oral surgery. Existing local studies have mostly focused on chlorhexidine solutions or gels for postoperative care rather than on the suture material itself.

This trial uses a split-mouth design, in which each participant receives both suture types at two symmetrical extraction sites, allowing a within-patient comparison that reduces the influence of individual differences. Bacterial load is measured from gingival crevicular fluid collected at the wound site using sterile autoclaved paper cones and quantified by viability real-time PCR (vPCR) for a panel of oral bacterial species. Soft tissue healing is evaluated using the IPR healing scale. Assessments are performed on days 3, 5, and 7 after surgery.

Inclusion Criteria:

• Patients aged 18 to 35 years
• Patients indicated for surgical removal of an impacted mandibular (lower) third molar
• Patients with two symmetrical impacted mandibular third molars of the same difficulty level according to the Pell-Gregory classification, with a difference in the angulation of the tooth axis (Winter classification) between the two teeth not exceeding 15 degrees

Exclusion Criteria:

• Patients whose adjacent mandibular second molar is severely decayed/broken down, has only a residual root, or has been extracted
• Patients using local or systemic antibiotics within 4 weeks before surgery
• Patients using anti-inflammatory drugs or hormonal medications
• Patients who are pregnant or breastfeeding
• Patients allergic to any component of 2% lidocaine with 1:100,000 epinephrine or to any other medication used in the study
• Patients with systemic diseases such as hypertension, diabetes mellitus, blood disorders, or immunodeficiency that may affect the study results
• Patients with poor oral hygiene, long-term smoking, or chronic alcohol dependence
• Patients with radiographic signs suggesting a tumor or cyst associated with the mandibular third molar