Pharmacology · single question
Which mouthwash ingredient causes tooth staining that can only be removed by professional prophylaxis?
Show answer and explanation
Correct answer: A. Cetylpyridinium chloride (CPC)
✓ A) Cetylpyridinium chloride (CPC) is correct per the answer key.
CPC is a quaternary ammonium antiseptic in many over-the-counter mouthwashes. It can cause tooth staining (brown/yellow discoloration of teeth and tongue) similar to chlorhexidine, though less severe. The staining results from interaction with tannins and dietary chromogens. It can only be removed by professional prophylaxis (scaling and polishing). Note: chlorhexidine gluconate is more commonly cited for significant staining on boards, but this question specifically identifies CPC as the answer.
CPC is a quaternary ammonium antiseptic in many over-the-counter mouthwashes. It can cause tooth staining (brown/yellow discoloration of teeth and tongue) similar to chlorhexidine, though less severe. The staining results from interaction with tannins and dietary chromogens. It can only be removed by professional prophylaxis (scaling and polishing). Note: chlorhexidine gluconate is more commonly cited for significant staining on boards, but this question specifically identifies CPC as the answer.
- A. CORRECT. Cetylpyridinium chloride (CPC) is a quaternary ammonium compound and antiseptic found in many over-the-counter mouthwashes (e.g., Scope, Cepacol). It causes yellow-brown extrinsic staining of the teeth and tongue, which can only be removed by professional prophylaxis. Chlorhexidine (prescription) also causes staining but is a different compound.
- B. Xylitol is a sugar alcohol with anticariogenic properties; it does not cause tooth staining.
- C. Sodium fluoride strengthens enamel and does not cause tooth staining.
- D. Hydrogen peroxide is a bleaching agent — it whitens teeth rather than staining them.