Effect of Irrigation Solution Temperature on Clinical Outcomes and Salivary CRP After Impacted Mandibular Third Molar Surgery

Effect of Irrigation Solution Temperature on Clinical Outcomes and Salivary CRP After Impacted Mandibular Third Molar Surgery: A Randomized Controlled Clinical Trial

Surgical extraction of impacted mandibular third molars often requires bone removal using rotary instruments, in which friction between the bur and bone generates heat. Excessive temperature rise may lead to local bone necrosis, delayed healing, and increased postoperative complications. Continuous irrigation with saline solution is routinely performed to reduce heat generation, and cold saline irrigation (0-4℃) has been shown to provide better thermal control than room-temperature saline.

This study aims to evaluate the effect of cold saline irrigation compared with room-temperature saline irrigation on postoperative outcomes following impacted mandibular third molar surgery. The assessed parameters include pain, swelling, trismus, and salivary C-reactive protein (CRP) levels as a biomarker of inflammation. Salivary CRP serves as a minimally invasive marker that reflects the systemic inflammatory response after surgery.

This randomized controlled trial will be conducted at the University of Medicine and Pharmacy at Ho Chi Minh City. Eligible patients with bilateral impacted mandibular third molars will be enrolled. Each patient will undergo extraction of one tooth with cold saline irrigation (0-4℃) and the contralateral tooth with room-temperature saline irrigation. Postoperative outcomes will include pain intensity (VAS) on days 1, 2, and 7; facial swelling on days 1, 2, and 7; trismus on days 1, 2, and 7; and salivary CRP levels at baseline and postoperative day 2.

The findings are expected to clarify the role of irrigation solution temperature in both subjective clinical outcomes and objective inflammatory markers, thereby providing evidence to optimize clinical protocols and reduce postoperative morbidity in third molar surgery.

Study Overview

• Status: Completed
• Conditions: Postoperative Complications; Third Molar Surgery; C-REACTIVE PROTEIN
• Intervention / Treatment: Procedure: Cold Saline Irrigation; Procedure: Room-Temperature Saline Irrigation (Control)

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Vietnam
  • Ho Chi Minh City, Vietnam, 700000
    • Faculty of Dentistry, University of Medicine and Pharmacy at Ho Chi Minh City

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy patients with an ASA physical status classification of I or II.
• Patients with bilaterally impacted mandibular third molars of comparable difficulty, with an angulation difference between the two teeth not exceeding 15 degrees, confirmed by clinical and panoramic radiographic examination.
• Patients who have provided written informed consent after being fully informed about the study purpose and procedures.

Exclusion Criteria:

• Patients presenting with systemic or local acute inflammation or infection at the surgical site.
• Patients with systemic diseases contraindicating surgical tooth extraction.
• Patients with a history of corticosteroid or anti-inflammatory drug use within 3 weeks prior to participation.
• Patients with clinical or radiographic signs suggestive of tumors (benign or malignant) associated with or adjacent to the impacted mandibular third molar.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cold Saline Irrigation	Procedure: Cold Saline Irrigation; During surgical extraction of impacted mandibular third molars, bone removal and irrigation will be performed using sterile saline cooled to 0-4°C to minimize heat generation
Active Comparator: Room-Temperature Saline Irrigation	Procedure: Room-Temperature Saline Irrigation (Control); During surgical extraction of impacted mandibular third molars, bone removal and irrigation will be performed using sterile saline at room temperature (approximately 25°C). This procedure serves as the control to compare the effects of irrigation temperature on postoperative outcomes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Facial Swelling	Facial swelling will be assessed by measuring three linear distances between standard facial landmarks: (1) tragus to pogonion, (2) gonion to lateral canthus, and (3) gonion to commissure. Postoperative swelling is measured as the change in facial dimension at each time point compared with the baseline measurement.	Baseline (preoperative) and postoperative days 1, 2, and 7
Postoperative Pain	Postoperative pain will be assessed using a 10-point Visual Analog Scale (VAS), where 0 represents no pain and 10 represents the worst imaginable pain.	Day 1, Day 2, and Day 7 after surgery
Trismus	Trismus will be evaluated by measuring the maximum interincisal distance (in millimeters) between the incisal edges of the upper and lower central incisors using a calibrated caliper. The degree of trismus will be determined by the reduction in mouth opening compared with the baseline (preoperative) measurement.	Baseline (preoperative) and postoperative days 1, 2, and 7
Salivary C-Reactive Protein (sCRP) Levels	Salivary C-reactive protein (sCRP) levels will be quantified using the ELISA method following the manufacturer's protocol	Baseline and postoperative day 2

Collaborators and Investigators

• Sponsor: University of Medicine and Pharmacy at Ho Chi Minh City

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2024
• Primary Completion (Actual): July 31, 2025
• Study Completion (Actual): July 31, 2025

Study Registration Dates

• First Submitted: November 17, 2025
• First Submitted That Met QC Criteria: November 17, 2025
• First Posted (Estimated): November 21, 2025

Study Record Updates

• Last Update Posted (Actual): November 25, 2025
• Last Update Submitted That Met QC Criteria: November 22, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Pathological Conditions, Signs and Symptoms; Postoperative Complications
• Other Study ID Numbers: Irrigation-CRP-2025; 269/2024/HĐ-ĐHYD (Other Grant/Funding Number: University of Medicine and Pharmacy at Ho Chi Minh City)

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