Cleaning vs Disinfection vs Sterilisation — ORE Part 1 MCQ
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Correct answer: B — Cleaning removes soil; disinfection reduces microbes; sterilisation includes spores
Explanation lettering: B = shown as A · A = shown as B · E = shown as C · C = shown as D · D = shown as E
A is correct. Cleaning removes adherent soil and contamination, helping subsequent processing to work effectively. Disinfection reduces the microbial load but is not the same as sterilisation. Sterilisation is the stage used for reusable invasive dental instruments and is intended to destroy micro-organisms, including bacterial spores. SDCEP-endorsed UK guidance describes instrument decontamination as a multistage process including cleaning, thermal disinfection, inspection and sterilisation. B and E incorrectly allocate the effects of the processes. C falsely treats cleaning and disinfection as equivalent and suggests sterilisation is optional. D is wrong because cleaning and disinfection do not replace sterilisation for instruments requiring sterile reprocessing.
Reference: Scottish Dental Clinical Effectiveness Programme (SDCEP), Practice Support Manual, “Decontamination of dental instruments”, current page, accessed July 2026. https://www.psm.sdcep.org.uk/topics/infection-prevention-and-control/decontamination-of-dental-instruments/