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Fissure sealants in high caries risk child — ORE Part 1 MCQ

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ModeratePaediatric DentistryFissure sealants in high caries risk childORE Part 1

An 11-year-old with high caries risk has newly erupted first and second permanent molars with deep fissures but no radiographic dentine caries. The child has poor plaque control but attends reliably with a parent. What is the correct anatomical/physiological mechanism by which fissure sealants reduce the caries risk in this patient?

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

Reveal the answer and explanation

Correct answer: A — A retained sealant creates a physical barrier that blocks plaque stagnation in fissures and reduces caries initiation

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

Fissure sealants work through a simple but highly effective mechanical mechanism: they form a physical barrier that occludes deep pits and fissures, preventing plaque and food debris from accumulating in these caries-prone sites. This blocks bacterial access and substrate availability, thus preventing caries initiation. In this patient with poor plaque control but a reliable attendance pattern, sealants are particularly valuable because they do not depend on the child's oral hygiene compliance—the barrier works regardless of brushing technique. Distractors misrepresent the mechanism: (B) sealants do not chemically modify dentine structure; (C) they do not alter salivary function; (D) they are used alongside fluoride toothpaste, not instead of it; (E) while sealants can arrest the progression of incipient (non-cavitated) lesions, they do not reverse established cavitated caries lesions independently. The question stem specifies 'no radiographic dentine caries,' making (E) irrelevant and (A) the clear correct answer.

Reference: SDCEP (Scottish Dental Clinical Effectiveness Programme). Prevention and Management of Dental Caries in Children: Professionally-delivered interventions. https://www.childcaries.sdcep.org.uk/guidance/caries-prevention/professionally-delivered-interventions/; Cochrane Oral Health (2022). Sealants for preventing dental caries in primary teeth. PubMed 35146744.