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Restorative & Materials · patient case question

Which statement about the function of saliva is correct?

Patient case: Counselling a patient about salivary protection

Patient: 29-year-old patient with a moderate caries history.

Chief complaint: Asks what saliva actually does for her teeth.

History: No medications, no xerostomia. Interested in prevention.

Findings: Normal salivary flow. Several restored surfaces, no active lesions.

  1. It impedes bacterial growth
  2. It decreases calculus build-up
  3. It binds to and dissolves hydroxyapatite
  4. It binds calcium and phosphate ions to remove them from the tooth surface
Show answer and explanation

Correct answer: A. It impedes bacterial growth

  • A. CORRECT. Saliva carries lysozyme, lactoferrin, salivary peroxidase, histatins and secretory IgA — an antimicrobial package that impedes bacterial growth and is specifically inhibitory toward S. mutans. Its other roles are lubrication, digestion, buffering and cleansing.
  • B. Saliva supplies the mineral ions that MINERALIZE plaque into calculus, so it contributes to calculus formation rather than reducing it.
  • C. Saliva protects hydroxyapatite through the acquired pellicle and mineral supply. Dissolution is what acid does.
  • D. Saliva is SUPERSATURATED with calcium and phosphate and DELIVERS these ions to remineralize enamel. It does not strip them away.

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