The effect of temperature of sodium hypochlorite on fracture resistance of endodontically treated teeth – An in vitro study

• Published in: Journal of conservative dentistry Vol. 28; no. 6; pp. 554 - 558
• Main Authors: Agarwal, Namrata, Nagamaheshwari, X., Kaushik, Mamta, Soujanya, E., Mehra, Neha, George, Alvin
• Format: Journal Article
• Language: English
• Published: India Medknow Publications and Media Pvt. Ltd 01.06.2025; Wolters Kluwer - Medknow
• Subjects: Care and treatment; Ethylenediaminetetraacetic acid; Original; Pain; Sodium hypochlorite; India; temperature; endodontically treated teeth; fracture resistance; Cryo-treated; sodium hypochlorite
• ISSN: 2950-4716; 0972-0707; 2950-4708; 2950-4708
• DOI: 10.4103/JCDE.JCDE_176_25

Sodium hypochlorite (NaOCl) is commonly used in endodontics for its strong antimicrobial properties, with heating enhancing its reactivity and ability to dissolve organic matter. Cryo-treated hypochlorite, however, can help reduce postendodontic pain. The chemical composition and temperature of irrigants play a key role in influencing the tooth structure's physical properties, potentially affecting treatment outcomes. The study aims to evaluate the effect of various temperatures of NaOCl which is 60°C, 45°C, 25°C, and 2°C on the fracture resistance of endodontically treated teeth. After the selection of 40 single-rooted teeth, the decoronation, and chemomechanical preparation was done, and the teeth were randomly assigned into four groups ( = 10 in each group) based on the final temperature of NaOCl. Group I at 60°C, Group II at 45°C, Group III at 2°C, and Group IV (control) at 25°C. The teeth were then tested for fracture resistance using a universal testing machine with a crosshead speed of 1 mm/min. One-way ANOVA and Tukey's tests were used. Group II (45°C) exhibited significantly higher fracture resistance compared to all other groups ( < 0.001), followed by Group III (2°C) and Group IV (25°C), whereas Group I (60°C) demonstrated the lowest fracture resistance. For optimal effectiveness, it is recommended to irrigate with NaOCl at a temperature of 45°C. This ensures enhanced antimicrobial activity. In addition, this temperature helps maintain the integrity of the endodontically treated teeth.