Cryotherapy and Intracanal Medicaments for Postoperative Pain in Apical Periodontitis

Effect of Intracanal Cryotherapy and Metformin on Postoperative Pain in Teeth With Symptomatic Apical Periodontitis: A Randomized Clinical Trial

This randomized clinical trial aimed to evaluate the effects of intracanal cryotherapy and two intracanal medicaments-calcium hydroxide and metformin-on postoperative spontaneous and percussion pain following root canal treatment in teeth with symptomatic apical periodontitis. In this double-blind, randomized, 2×2 factorial clinical trial, 80 patients with symptomatic apical periodontitis in mandibular premolars were enrolled and randomly assigned to four groups: calcium hydroxide, metformin, cryotherapy plus calcium hydroxide, and cryotherapy plus metformin. All teeth underwent standardized single-visit root canal treatment, and in the cryotherapy groups, final irrigation was performed using sterile saline at 4 °C. Spontaneous pain was assessed preoperatively and daily for 7 postoperative days, while percussion pain was evaluated preoperatively and postoperatively. Pain intensity was recorded using a 100-mm visual analog scale (VAS). Data were analyzed using mixed-effects models for repeated measures and analysis of covariance (ANCOVA) (α = 0.05).

Inclusion Criteria:

• systemically healthy
• Mandibular premolar teeth diagnosed with pulpal necrosis and indicated for root canal treatment.
• Periapical index score between 0 and 2.
• Aged between 18 and 70 years.
• Able to understand and complete visual analog scale (VAS) assessments.
• Provided written informed consent.

Exclusion Criteria:

• Any systemic disease or pregnancy.
• Use of analgesics within 24 hours prior to treatment.
• Severe bruxism.
• Presence of acute apical abscess or swelling.
• Periodontal pocket depths greater than 5 mm or tooth mobility exceeding grade 1.
• Teeth deemed unrestorable.
• Presence of vital pulpal tissue or immature apices
• Radiographic evidence of root resorption, root fracture, perforation, or canal calcification.