Restorative & Materials · patient case question
All of the following contributed to the demineralization EXCEPT:
Patient case: Seven Restorations and White Lines at the Gumline
Patient: 22-year-old female
Chief Complaint: Routine examination. “My braces came off last year.”
Background: Fixed orthodontic appliances removed 14 months ago. Drinks sweetened iced coffee through the day. Has not been seen for two years. Brushes once daily, does not floss.
Medications: None
Vital Signs: BP 112/70 mmHg · HR 70 bpm · RR 14 · T 98.2°F
Findings: Seven existing restorations. Chalky white demineralized bands along the gingival third of the buccal surfaces of all premolars. Generalized plaque at the gingival margins with marginal erythema. No cavitation.
Show answer and explanation
Correct answer: D. The orthodontic bands themselves
- A. This IS a contributor. Regular recall permits early detection, professional fluoride application and reinforcement of preventive behaviour.
- B. This IS a contributor. Demineralization requires a mature acidogenic biofilm in direct contact with enamel.
- C. This IS a contributor, and the most important one. It is the FREQUENCY of fermentable carbohydrate exposure, not the quantity, that determines how much time enamel spends below the critical pH of 5.5.
- D. CORRECT — this is the EXCEPTION. Orthodontic appliances do not demineralize enamel. They are inert. What they do is create plaque-retentive sites that are difficult to clean, so the appliance is a RETENTIVE factor, not a causative one. Enamel dissolves because acidogenic biofilm sits undisturbed on it — bands with meticulous hygiene and fluoride produce no white spots at all.
Note: The distinction between a plaque-RETENTIVE factor and a causative factor matters: removing the appliance does not cure the disease if diet and hygiene do not change.
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