970-nm Diode Laser Versus Liquid Nitrogen Cryotherapy in Maxillary Labial Frenectomy (MLF-DL-KRYO)

Comparison of Salivary Cortisol Response and Early Postoperative Outcomes Following 970-nm Diode Laser and Liquid Nitrogen Cryotherapy in Maxillary Labial Frenectomy: A Randomized Single-Blind Clinical Trial

This prospective, randomized, single-blind, assessor-blinded, parallel-group clinical trial aims to compare the effects of 970-nm diode laser and liquid nitrogen cryotherapy in patients requiring maxillary labial frenectomy.

The primary objective is to compare the change in salivary cortisol levels from baseline to postoperative day 2 between the two treatment groups. Secondary objectives include comparison of postoperative pain, edema, interincisal mouth opening, analgesic consumption, operation duration, state anxiety, clinical wound healing, and adverse events.

Eligible adult patients with an indication for maxillary labial frenectomy will be randomly assigned to receive either 970-nm diode laser frenectomy or liquid nitrogen cryotherapy. Salivary cortisol samples and clinical outcomes will be assessed during the early postoperative follow-up period.

Study Overview

• Status: Not yet recruiting
• Conditions: Maxillary Labial Frenulum Abnormality; Hypertrophic Maxillary Labial Frenulum
• Intervention / Treatment: Procedure: 970-nm Diode Laser Frenectomy; Procedure: Liquid Nitrogen Cryotherapy

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Muhammet Yasin Pektaş, Asst. Prof, DDS; Phone Number: +905541351195; Email: muhammetyasin.pektas@ksbu.edu.tr

Study Locations

• Turkey (Türkiye)
  • Kütahya
    • Kütahya, Kütahya, Turkey (Türkiye), 43020
      • Kutahya Health Sciences University Faculty of Dentistry
      • Contact: Muhammet Yasin Pektaş, Asst. Prof., DDS; Phone Number: +905541351195; Email: muhammetyasin.pektas@ksbu.edu.tr
      • Contact: Email: mypektas42@gmail.com
      • Principal Investigator: Muhammet Yasin Pektaş, Asst. Prof., DDS

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: 970-nm Diode Laser Frenectomy; Participants randomized to this arm will undergo maxillary labial frenectomy using a 970-nm diode laser. The procedure will be performed with a SiroLaser Advance device at 970 nm wavelength, 2 W power, continuous wave mode, and a 320-micrometer sterile fiber tip using a contact technique. The total laser application time will be standardized as 2 minutes. The surgical area will not be sutured and will be left to heal by secondary intention.	Procedure: 970-nm Diode Laser Frenectomy; Maxillary labial frenectomy will be performed using a 970-nm diode laser device at 2 W power in continuous wave mode with a 320-micrometer sterile fiber tip using a contact technique. The total laser application time will be standardized as 2 minutes. The surgical area will not be sutured and will be left to heal by secondary intention.; Other Names: Diode laser frenectomy
Experimental: Liquid Nitrogen Cryotherapy; Participants randomized to this arm will receive liquid nitrogen cryotherapy applied to the maxillary labial frenulum region using an open-spray technique. Two freeze-thaw cycles will be performed; each freezing cycle will last 15 seconds, with passive complete thawing between cycles. No mechanical excision will be performed after cryotherapy. The target tissue is expected to be eliminated through cryogenic necrosis and secondary healing. The surgical area will not be sutured.	Procedure: Liquid Nitrogen Cryotherapy; Liquid nitrogen cryotherapy will be applied to the maxillary labial frenulum region using an open-spray technique. Two freeze-thaw cycles will be performed; each freezing cycle will last 15 seconds, with passive complete thawing between cycles. No mechanical excision will be performed after cryotherapy, and the surgical area will not be sutured.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in salivary cortisol level from baseline to postoperative day 2	Salivary cortisol will be measured in unstimulated saliva samples using an ELISA method. For each participant, the change in salivary cortisol level from the preoperative baseline measurement to postoperative day 2 will be calculated and compared between the two intervention groups. Results will be recorded in nmol/L.	Baseline and postoperative day 2

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in salivary cortisol level from baseline to postoperative day 7	Salivary cortisol will be measured in unstimulated saliva samples using an ELISA method. For each participant, the change in salivary cortisol level from the preoperative baseline measurement to postoperative day 7 will be calculated and compared between the two intervention groups. Results will be recorded in nmol/L.	Baseline and postoperative day 7
Change in postoperative edema	Postoperative edema will be assessed using standardized facial measurements. Changes in edema measurements from baseline to postoperative day 2 and postoperative day 7 will be calculated and compared between the two intervention groups.	Baseline, postoperative day 2, and postoperative day 7
Postoperative pain intensity	Postoperative pain intensity will be assessed using a 0-to-10 visual analog scale, where higher scores indicate greater pain intensity.	Postoperative 6 hours, 12 hours, 24 hours, day 2, and day 7
Change in interincisal mouth opening	Interincisal mouth opening will be measured in millimeters. Changes from baseline to postoperative day 2 and postoperative day 7 will be calculated and compared between the two intervention groups.	Baseline, postoperative day 2, and postoperative day 7
Total analgesic consumption during the first postoperative week	Analgesic consumption will be recorded as the total number of analgesic tablets used by each participant during the first postoperative week.	Postoperative days 0 to 7
Operation duration	Operation duration will be recorded in minutes for each participant and compared between the two intervention groups.	During the intervention procedure
State anxiety score	State anxiety will be assessed using the State-Trait Anxiety Inventory-State form. Total scores will be recorded preoperatively and on postoperative days 2 and 7, and compared between the two intervention groups.	Baseline, postoperative day 2, and postoperative day 7
Clinical wound healing score	Clinical wound healing will be assessed using the Landry, Turnbull and Howley Wound Healing Index. Wound healing scores will be recorded on postoperative days 2, 7, 14, and 21 and compared between the two intervention groups.	Postoperative days 2, 7, 14, and 21
Postoperative complications and adverse events	The occurrence of postoperative complications or adverse events, including unexpected pain, bleeding, infection, wound healing problems, or other procedure-related adverse events, will be recorded during the follow-up period.	From the intervention procedure through postoperative day 21

Collaborators and Investigators

• Sponsor: Kutahya Health Sciences University
• Investigators: Principal Investigator: Muhammet Yasin Pektaş, Asst. Prof, DDS, Kutahya Health Sciences University, Faculty of Dentistry, Department of Oral and Maxillofacial Surgery

Publications and helpful links

General Publications

• Opaleye T, Okoturo E, Adesina OA, Oyapero A, Salami Y, Wemambu JC. Salivary Cortisol as a Stress Monitor During Third Molar Surgery. J Maxillofac Oral Surg. 2022 Dec;21(4):1112-1118. doi: 10.1007/s12663-020-01480-2. Epub 2020 Nov 22.
• Georgakopoulou E, Loumou P, Sgouros D, Chaurasia A, Panagiotopoulos A. Cryosurgery in oral lesions. J Clin Exp Dent. 2025 Oct 1;17(10):e1257-e1266. doi: 10.4317/jced.63133. eCollection 2025 Oct.
• Sobouti F, Moallem Savasari A, Aryana M, Hakimiha N, Dadgar S. Maxillary labial frenectomy: a randomized, controlled comparative study of two blue (445 nm) and infrared (980 nm) diode lasers versus surgical scalpel. BMC Oral Health. 2024 Jul 25;24(1):843. doi: 10.1186/s12903-024-04364-w.

Study record dates

Study Major Dates

• Study Start (Estimated): July 30, 2026
• Primary Completion (Estimated): May 2, 2027
• Study Completion (Estimated): May 21, 2027

Study Registration Dates

• First Submitted: July 13, 2026
• First Submitted That Met QC Criteria: July 13, 2026
• First Posted (Actual): July 16, 2026

Study Record Updates

• Last Update Posted (Actual): July 16, 2026
• Last Update Submitted That Met QC Criteria: July 13, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Wound healing; Postoperative pain; Diode laser; Salivary cortisol; Maxillary labial frenectomy; 970-nm diode laser; Liquid nitrogen cryotherapy
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Postoperative Complications; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative
• Other Study ID Numbers: MLF-DL-KRYO-2026-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No