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Enamel Bonding — MFDS Part 1 MCQ

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ModerateDental MaterialsEnamel BondingMFDS Part 1

Following phosphoric-acid etching, what is the principal mechanism by which a resin-based composite restoration is bonded to enamel?

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Correct answer: BMicromechanical interlocking of polymerised adhesive resin within acid-created enamel microporosities

Phosphoric acid selectively demineralises enamel and creates a microporous surface. Low-viscosity adhesive resin penetrates these microporosities and polymerises, producing resin tags and micromechanical interlocking; therefore B is correct. The etching pattern may involve prism cores, prism peripheries or both, so retention should not be attributed only to prism cores. Chemical or ionic interactions may occur with some functional monomers but are not the principal mechanism of conventional bonding to etched enamel. A resin–collagen hybrid layer is associated with dentine bonding because enamel does not contain a collagen network. Adhesive composite restorations also do not depend primarily on cavity undercuts.

Reference: Perdigão J. Current perspectives on dental adhesion: (1) Dentin adhesion—not there yet. Japanese Dental Science Review. 2020;56(1):190–207. https://pubmed.ncbi.nlm.nih.gov/34188727/