Pathology · patient case question
Given her medication-induced xerostomia and new cervical caries, which dentifrice ingredient most directly reduces her caries risk?
Patient case: Gums That Peel
Patient: 61-year-old female
Chief Complaint: “My gums peel away and I keep getting blisters that pop and leave raw spots.”
Background: Symptoms present for 5 months and worsening. Difficulty eating due to pain. She also reports persistent dry mouth. No known autoimmune disease.
Medications: Sertraline · Oxybutynin · Loratadine
Vital Signs: BP 130/80 mmHg · HR 76 bpm · RR 16 · T 98.6°F
Findings: Diffuse erythematous, desquamating attached gingiva in all quadrants. Flaccid bullae on the buccal mucosa that rupture readily, leaving ragged, painful ulcers. Firm lateral pressure on clinically uninvolved mucosa induces epithelial sloughing. Reduced salivary pooling; multiple new cervical carious lesions since her last visit.
Show answer and explanation
Correct answer: B. Sodium fluoride
- A. Incorrect. Sodium bicarbonate is a mild abrasive with modest buffering capacity. It is not an established anticaries agent.
- B. Correct. Fluoride is the anticaries agent in dentifrice. It reduces enamel solubility by forming fluorapatite, promotes remineralization of early lesions, and inhibits bacterial enolase. In a xerostomic patient, a high-concentration 5000 ppm prescription fluoride paste is the appropriate escalation.
- C. Incorrect. Sodium lauryl sulfate is a detergent and foaming agent. It has no anticaries effect and may aggravate aphthous ulceration and mucosal irritation in susceptible patients.
- D. Incorrect. Hydrated silica is the abrasive component that removes extrinsic stain and biofilm mechanically. It contributes nothing chemically to caries prevention.
Note: Distinguish the agents: stannous fluoride provides both anticaries and antimicrobial action; sodium fluoride is the standard dentifrice anticaries agent; silver diamine fluoride is a professionally applied agent for arresting active caries, not a dentifrice ingredient.