title: Dentin caries zones: mineral, structure, and properties.
abstract: Caries Detector staining reveals 4 zones in dentin containing caries lesions, but characteristics of each zone are not well-defined. We therefore investigated the physical and microstructural properties of carious dentin in the 4 different zones to determine important differences revealed by Caries Detector staining. Six arrested dentin caries lesions and 2 normal controls were Caries-Detector-stained, each zone (pink, light pink, transparent, apparently normal) being analyzed by atomic force microscopy (AFM) imaging for microstructure, by AFM nano-indentation for mechanical properties, and by transverse digital microradiography (TMR) for mineral content. Microstructure changes, and nanomechanical properties and mineral content significantly decreased across zones. Hydrated elastic modulus and mineral content from normal dentin to pink Caries-Detector-stained dentin ranged from 19.5 [10.6-25.3] GPa to 1.6 [0.0-5.0] GPa and from 42.9 [39.8-44.6] vol% to 12.4 [9.1-14.2] vol%, respectively. Even the most demineralized pink zone contained considerable residual mineral.
authors.affiliation: Department of Preventive and Restorative Dental Sciences, University of California, 707 Parnassus Ave. Box 0758, Dentistry 2246, San Francisco, CA 94143-0758, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Pugach
authors.forename: J
authors.initials: J
authors.lastname: Strother
authors.forename: C L
authors.initials: CL
authors.lastname: Darling
authors.forename: D
authors.initials: D
authors.lastname: Fried
authors.forename: S A
authors.initials: SA
authors.lastname: Gansky
authors.forename: S J
authors.initials: SJ
authors.lastname: Marshall
authors.forename: G W
authors.initials: GW
authors.lastname: Marshall
mesh_terms: D001696:Biomechanical Phenomena; D003731:Dental Caries / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D003804:Dentin / Q000737:chemistry / Q000648:ultrastructure*; D055119:Elastic Modulus; D005456:Fluorescent Dyes; D006244:Hardness; D006801:Humans; D007202:Indicators and Reagents; D008852:Microradiography; D018625:Microscopy, Atomic Force; D008903:Minerals / Q000032:analysis; D036103:Nanotechnology; D011409:Propylene Glycols; D012235:Rhodamines; D017001:Tooth Demineralization / Q000378:metabolism / Q000473:pathology
chemical_list: C089090:Caries Detector; D005456:Fluorescent Dyes; D007202:Indicators and Reagents; D008903:Minerals; D011409:Propylene Glycols; D012235:Rhodamines