Restorative & Materials · patient case with 2 questions
Two patients with discoloured teeth
Patient: Adult female, 33 years old — and a separate paediatric patient, male, 9 years old
Chief Complaint: Adult: “My teeth have grey bands across them and I hate smiling.” Child: mother noticed a white patch on an upper canine.
Background: The adult was treated with a tetracycline antibiotic for a prolonged period in early childhood. The child has good hygiene, drinks fluoridated water, and the mark has been present since the tooth erupted.
Findings: Adult: generalised horizontal grey-brown banding of the full dentition, enamel intact and smooth. Child: a well-demarcated opaque white area on the buccal surface of a canine in the MIDDLE third, smooth on probing, no cavitation, away from the gingival margin.
Question 1
Each of the following is an appropriate treatment option for the adult's tetracycline staining EXCEPT one. Which is the EXCEPTION?
Show answer and explanation
Correct answer: A. Systemic fluoride supplementation
- A. CORRECT as the exception. Systemic fluoride does nothing for tetracycline staining. The discolouration is INTRINSIC — tetracycline chelated with calcium and was incorporated into the dentine during tooth formation. Fluoride affects mineralisation and caries risk, not existing intrinsic colour, and excess systemic fluoride causes its own discolouration in the form of fluorosis.
- B. Direct composite veneers are a conservative masking option, particularly useful when the patient wants a reversible or lower-cost approach.
- C. Porcelain veneers are the definitive treatment for moderate to severe banding, though the darkest cases may need opaquing or full-coverage crowns to block the underlying colour.
- D. Extended external bleaching is a legitimate first-line option for tetracycline staining, though it needs far longer than for extrinsic stain — often three to six months of nightly tray use — and results are best for the milder first-degree cases.
Question 2
What is the most likely diagnosis for the white lesion on the child's canine?
Show answer and explanation
Correct answer: A. Enamel hypocalcification
- A. CORRECT. The location is what decides this. The lesion sits in the MIDDLE THIRD of the buccal surface — a self-cleansing area away from the gingival margin — it has been present since eruption, and the surface is smooth and intact. That is a developmental defect of MINERALISATION: the enamel matrix formed to normal thickness but did not fully mineralise. Hypocalcification.
- B. Hypoplasia is a quantitative defect — the enamel is thin or pitted, so the surface is visibly and palpably deficient. This surface is smooth and intact.
- C. Fluorosis is symmetrical and generalised across teeth that developed at the same time, not a single isolated patch on one tooth.
- D. Incipient caries (a white spot lesion) appears along the GINGIVAL third and around brackets or margins where plaque stagnates, develops after eruption, and typically feels chalky or slightly roughened. The location here argues against it.
Note: Location is the discriminator worth memorising: gingival third and post-eruptive points to demineralisation; middle third, present at eruption, smooth surface points to hypocalcification.