6: Dental hard tissues

6

Dental hard tissues

Figure 6.1 Scanning electron micrograph (×1000) of etched enamel.

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Figure 6.2 Scanning electron micrograph (×1000) of dentin tubules with smear layer present.

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Box 6.1 Changes in dental enamel with patient age
Permeability decreases.
Water content decreases.
Surface composition changes through ion exchange with oral environment (e.g., fluoridation of enamel surface).
Color darkens, in part through addition of organic matter to the enamel and sclerosis and staining of underlying dentin.
Wear facets occur in areas of heavy function.


Box 6.2 Proteinaceous components of dentin
Collagenous proteins

(mainly Type I collagen with smaller amounts of Type V and Type I trimer collagens)
Noncollagenous dentin-specific proteins

(phosphophoryns, dentin sialoprotein, and dentin matrix protein-1)
Nonspecific proteins associated with mineralized tissues

(e.g., osteocalcin and osteopontin)

Table 6.1 Characteristics of dental hard tissues

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Table 6.2 Average inorganic constituents content (wt.%) of mineralized tissue

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Table 6.3 Inorganic and organic content (wt.%) of enamel and dentin

Enamel Dentin
Mineral (hydroxyapatite) content 96 70
Organic matter 1 20
Water 3 10

Table 6.4 Characteristics of dentinal tubules

Near DEJ Near pulp
Dens/>

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Jan 1, 2015 | Posted by in Dental Materials | Comments Off on 6: Dental hard tissues
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