skip to main content

Secondary caries beneath a crown margin — ORE Part 1 MCQ

Instant feedback + full explanation. One question, done properly.

HardRestorative DentistrySecondary caries beneath a crown marginORE Part 1

A 63-year-old patient has a metal-ceramic crown on an upper premolar placed eight years ago. Bitewing radiography shows recurrent caries extending beneath an open distal margin, and the tooth is vital with no apical change. The crown margin is clinically defective and plaque-retentive. What is the most appropriate treatment?

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

Reveal the answer and explanation

Correct answer: B — Remove the crown, assess restorability, remove caries and provide a new sealed restoration

Explanation lettering: E = shown as A · A = shown as D · D = shown as E

An open, defective crown margin with secondary caries extending beneath it presents a complex restorative challenge requiring assessment of underlying tooth restorability before treatment can be finalised. Crown removal is mandatory because: (1) it permits full visualisation of caries extent and remaining tooth structure; (2) it enables assessment of restorability and prognosis; (3) it allows definitive caries removal and sealed restoration placement, whether by core-and-crown or other means; (4) leaving a defective, plaque-retentive margin perpetuates secondary caries risk. Fluoride varnish (A) cannot seal an open margin. Porcelain repair (C) ignores the caries and margin defect. Antibiotics (D) are unjustified without systemic involvement and delay diagnosis. Endodontic access (E) is inappropriate in a vital tooth with no apical pathology.

Reference: Alomari QD, Alsaeed A, et al. Recurrent caries at crown margins: making a decision on treatment. Int J Dent. 2009. PubMed ID 19349720. https://pubmed.ncbi.nlm.nih.gov/19349720/