970-nm Diode Laser Versus Liquid Nitrogen Cryotherapy in Maxillary Labial Frenectomy

Maxillary labial frenulum abnormalities may be associated with diastema, plaque accumulation, periodontal irritation, gingival recession, oral hygiene difficulty, functional discomfort, and esthetic concerns. Frenectomy may be indicated when the frenulum is hypertrophic, short, thick, or inserted close to the interdental papilla.

Conventional scalpel frenectomy is effective but may be associated with intraoperative bleeding, need for suturing, postoperative pain, edema, and reduced patient comfort. Minimally invasive approaches such as diode laser surgery and cryotherapy may offer potential advantages in oral soft tissue procedures.

This study will compare two minimally invasive approaches for maxillary labial frenectomy: 970-nm diode laser and liquid nitrogen cryotherapy. Participants will be randomized into two parallel groups. In the diode laser group, frenectomy will be performed using a 970-nm diode laser at 2 W in continuous wave mode with a 320-micrometer sterile fiber tip using a contact technique. In the liquid nitrogen cryotherapy group, open-spray cryotherapy will be applied to the maxillary labial frenulum region with two freeze-thaw cycles.

The primary endpoint is the change in salivary cortisol level from baseline to postoperative day 2. Secondary endpoints include postoperative day 7 salivary cortisol change, postoperative pain measured by visual analog scale, edema, interincisal mouth opening, total analgesic consumption, operation duration, State-Trait Anxiety Inventory-State score, Landry, Turnbull and Howley wound healing index scores, and postoperative complications or adverse events.

All procedures and salivary sampling will be standardized and performed in the morning to reduce the influence of circadian variation on cortisol measurements. The study will be conducted at the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Kutahya Health Sciences University.

Inclusion criteria

• Age between 18 and 65 years.
• Systemically healthy, ASA I status.
• Clinical indication for maxillary labial frenectomy.
• Ability to attend postoperative follow-up visits.
• Provision of written informed consent.

Exclusion criteria

• Systemic or local corticosteroid use within the last 6 months.
• Endocrine disease that may affect cortisol levels.
• Pregnancy or lactation.
• Active oral infection.
• Chronic analgesic or anti-inflammatory drug use.
• Psychiatric medication use.
• Smoking.
• ASA II or higher systemic status.
• Inability to attend follow-up visits.
• Refusal to participate in the study.