Root Canal Irrigation — ORE Part 1 MCQ
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Correct answer: E — Dissolving organic tissue and killing microorganisms
Explanation lettering: B = shown as A · D = shown as B · E = shown as C · C = shown as D · A = shown as E
The correct answer is A. Sodium hypochlorite is used principally because it is antimicrobial and dissolves organic material, including pulp remnants and necrotic tissue. Its antimicrobial effect includes oxidative injury to microbial cell components and enzyme inactivation. B is incorrect because chelation and removal of the inorganic component of smear layer are principally achieved with EDTA or similar chelators. C may be associated with some endodontic preparations, but lubrication is not sodium hypochlorite’s principal action. D is a function of mechanical instrumentation rather than hypochlorite irrigation. E is not a property or clinical purpose of sodium hypochlorite.
Reference: Estrela C, Estrela CRA, Barbin EL, Spano JCE, Marchesan MA, Pécora JD. Mechanism of action of sodium hypochlorite. Brazilian Dental Journal. 2002. https://pubmed.ncbi.nlm.nih.gov/12238801/