C

As an active carious lesion arrests, the exposed dentine undergoes sclerosis and surface remineralization, becoming hard, smooth and shiny—a glass-like change traditionally called “eburnation” of dentine, which is characteristic of arrested (inactive) caries rather than acute, chronic-progressive or root lesions [Schüpbach 1992, PMID 1628289; Kidd & Fejerskov 2004, PMID 15286119].