Biological Width — ORE Part 1 MCQ

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HardPeriodontologyBiological WidthORE Part 1

For a crown margin planned close to the alveolar crest, which statement most accurately describes the conventional biological width (supracrestal tissue attachment) and its restorative significance?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — About 2 mm; preserve it when positioning a restorative margin

Explanation lettering: C = shown as B · E = shown as C · B = shown as D · D = shown as E

A is correct. Biological width, now often termed the supracrestal tissue attachment, comprises junctional epithelium and supracrestal connective-tissue attachment. Its conventional teaching value is approximately 2 mm, although systematic-review evidence shows clinically important variation between sites and individuals. A restoration placed too deeply may encroach on this attachment and compromise periodontal health; therefore the margin should be planned with the periodontal tissues and, where necessary, crown-lengthening or orthodontic extrusion considered. B is unrelated to determining clinical crown height. C incorrectly minimises both the dimension and its clinical relevance. D confuses periodontal attachment with the post-dam of a denture. E confuses a natural-tooth periodontal dimension with implant selection.

Reference: Schmidt JC, et al. Biologic width dimensions--a systematic review. Journal of Clinical Periodontology. 2013. https://pubmed.ncbi.nlm.nih.gov/3295199/