Sodium hypochlorite is the most popular irrigant due to its proteolytic properties, but it affects not only the necrotized remnants of pulp tissue, the lubricated layer and microbial biofilm, but alsothe collagen fibers of the organic dentin matrix. This adversely affects the strength of dentin andincreases the risks of complications of endodontic treatment with chewing load. Determining theeffect of sodium hypochlorite and the temperature regime of its irrigation on the structuralcomponents of dentin will help to balance the risks and benefits of using this irrigant in endodonticpractice.The aim of this review article is to systematic assessment of scientific data on the effect ofsodium hypochlorite and the temperature regime of its irrigation on the hard tissues of the tooth, inparticular on the mechanical properties of dentin.Electronic search of articles was carried out using search engines and databases GoogleScholar, Pub Med. The articles are included, the content of which concerns the topics of practicalapplication of sodium hypochlorite solution, as well as the influence of the temperature of thissolution on the properties of hard tooth tissues. The publication date criterion has been selectedsince July 201169 articles were reviewed during the review process. After analyzing the literature according tothe inclusion criteria, the total number was 14 publications.Prolonged exposure to the irritant, irreversible changes in dentin occur due to the dissolution ofcollagen, which leads to irreversible changes in the physical and mechanical properties of dentin © 2021, Journal of International Dental and Medical Research. All Rights Reserved.