Self-Etch vs Total-Etch — ORE Part 1 MCQ

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ModerateDental MaterialsSelf-Etch vs Total-EtchORE Part 1

A 35-year-old patient is having a composite restoration placed using a self-etch adhesive system. Which feature distinguishes a self-etch system from an etch-and-rinse (total-etch) system?

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

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Correct answer: C — It uses acidic monomers to etch and prime without a separate phosphoric-acid step

Explanation lettering: B = shown as A · C = shown as B · A = shown as C

Self-etch adhesives contain acidic functional monomers that condition the surface and prime it in the same clinical stage; therefore, a separate phosphoric-acid etch followed by rinsing is not intrinsic to their use. In contrast, etch-and-rinse (total-etch) systems use phosphoric acid first, then are rinsed before adhesive application. B reverses the usual distinction: phosphoric acid is the separate etchant used in etch-and-rinse protocols. C is false because self-etch systems can bond to both enamel and dentine, although phosphoric acid generally produces a more pronounced enamel etch pattern. D describes the rinse stage of an etch-and-rinse protocol. E is false because self-etch systems still create a resin-infiltrated bonding interface with tooth structure.

Reference: Van Meerbeek B, et al. Self-etch and etch-and-rinse adhesive systems in clinical dentistry. 2013. https://pubmed.ncbi.nlm.nih.gov/23550327/