Infection Control · single question
Which of the following is BEST for disinfecting smooth (clinical contact) surfaces in the dental office?
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Correct answer: B. Isopropyl alcohol (70%)
- A. Phenol-based disinfectants are EPA-registered and effective but have environmental and toxicity concerns; alcohol is simpler and more commonly used for smooth surfaces.
- B. ALCOHOL (isopropyl or ethyl alcohol, 70%–90%) is an effective intermediate-level disinfectant for smooth clinical contact surfaces. It kills bacteria (including TB), fungi, and most viruses. However, it evaporates quickly and has no residual activity — best for smooth, non-porous surfaces.
- C. Lysol (quaternary ammonium compounds/quats) have limited spectrum — they do NOT kill Mycobacterium tuberculosis or non-enveloped viruses. Not ideal for dental environmental surfaces requiring intermediate-level disinfection.
- D. Ammonia-based cleaners are DETERGENTS/CLEANERS, not disinfectants — they do not reliably kill pathogens to CDC standards.
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