Silver diamine fluoride arrests caries by all of the following mechanisms EXCEPT:

Correct answer: D. Increasing calcium resorption from the tooth

• A. The alkaline ammonia component raises pH, which shifts the demineralization–remineralization equilibrium toward remineralization.
• B. Silver ions are potently antimicrobial, denaturing bacterial proteins and disrupting cell membranes and biofilm.
• C. Silver-protein conjugates and mineral precipitate physically occlude the tubules, which is why SDF also reduces dentinal hypersensitivity.
• D. CORRECT — this is the EXCEPT, and it is the reverse of what happens. SDF DEPOSITS mineral. It does not remove calcium from the tooth. Silver phosphate and calcium fluoride precipitate within the lesion, and fluorapatite forms in the surface layer.

Note: The black staining is the arrested lesion itself: silver phosphate oxidizing to metallic silver. It stains carious dentin, not sound tooth structure, and the discolouration is a marker of success. Always consent for it with a photograph.