Effect of Intracanal Cryotherapy on Postoperative Endodontic Pain

Inclusion criteria

• Systemically healthy patients with 18-70 years of age
• Single-rooted teeth with a single root canal, diagnosed with either AIP and normal periapical tissues or AAP.

Pulpal and periapical diagnoses were established according to the American Association of Endodontists (AAE) [20] diagnostic terminology. Included teeth were categorized into 2 diagnostic groups: AIP with normal periapical tissues and AAP associated with pulp necrosis. AIP was provisionally diagnosed in teeth with extremely deep caries approximating or reaching the pulp, a positive response to cold testing (Dispodent, Nadu, India), and no clinical symptoms. Periapical radiographs showed a PAI score of 1 without periodontal ligament widening. The diagnosis was confirmed intraoperatively by persistent pulpal bleeding that remained uncontrolled after 10 minutes of application of a sterile cotton pellet moistened with 2.5% sodium hypochlorite. AAP was diagnosed in teeth with a PAI score of ≥3 in the absence of clinical symptoms. None of the included teeth exhibited tenderness to percussion. All periapical radiographs were obtained using a phosphor storage plate system and the paralleling technique (Myray parallel holder, NDental, Imola, Italy) under standardized exposure parameters (70 kV, 8 mA, 0.360 s).

Exclusion criteria

1) Teeth with canal calcification, complex or atypical canal anatomy, root resorption, incomplete root development, or a history of endodontic treatment of the study tooth.

• Teeth initially diagnosed with AIP in which pulpal bleeding was controlled within 10 min after access cavity preparation, as these teeth were considered eligible for vital pulp therapy.

• Teeth initially diagnosed with AIP in which pulp necrosis was identified after access cavity preparation.

• Teeth in which root canal treatment could not be completed in a single visit.

• Patients who had taken analgesics within 12 hours before the appointment or antibiotics within the previous month.

• Teeth with periodontal probing depths >3 mm or clinical/radiographic signs of periodontal disease.

• Teeth with insufficient coronal tooth structure to allow an adequate ferrule.

• Pregnant or breastfeeding patients and patients with systemic conditions or regular medication use that could affect treatment outcomes.