Impression Disinfection — ORE Part 1 MCQ

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EasyDental MaterialsImpression DisinfectionORE Part 1

After rinsing an elastomeric dental impression under running water, which sodium hypochlorite immersion regimen is appropriate for decontamination before it is sent to the laboratory?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: B — 1% sodium hypochlorite for 10 minutes

Explanation lettering: B = shown as A · A = shown as B · E = shown as C · C = shown as E

A is correct. For an elastomeric impression, immersion disinfection for 10 minutes with sodium hypochlorite in the 0.5–1% range is supported as effective against oral flora and common oral pathogens. Therefore, 1% for 10 minutes is an appropriate regimen. B uses a concentration below the evidence-supported range. C has an appropriate concentration but insufficient contact time. D and E use unnecessarily concentrated hypochlorite solutions; increasing concentration does not compensate for choosing a non-standard regimen and may adversely affect impression materials or handling safety. The impression should first be rinsed to remove visible contamination and then be clearly identified as decontaminated when transferred to the laboratory.

Reference: Qiu Y, Xu J, Xu Y, et al. Disinfection efficacy of sodium hypochlorite and glutaraldehyde and their effects on the dimensional stability and surface properties of dental impressions: a systematic review. PeerJ. 2023. https://pubmed.ncbi.nlm.nih.gov/36846444/