Dentin

Which dentin forms after root completion and is deposited unevenly?

Secondary dentin

Which dentin is produced only in reaction to a stimulus?

Tertiary dentin

First-formed dentin adjacent to the DEJ and CDJ

Mantle dentin

Dentin that outlines the pulp

Circumpulpal dentin

Collagen type in von Korff's fibers

Type III

Large-diameter fibrils that are first to form predentin

Von Korff's fibers

Mild stimulus produces which tertiary dentin?

Reactionary dentin

Severe stimulus produces which tertiary dentin?

Reparative dentin

Cells that form reactionary dentin

Preexisting odontoblasts

Cells that form reparative dentin

Odontoblast-like cells

Unmineralized layer between pulp and dentin

Predentin

Thin organic sheath lining the dentinal tubule

Lamina limitans

Cytoplasmic extension inside the tubule, also called Tomes' fiber

Odontoblastic process

Embryonic origin of dentin

Dental papilla

Structure that initiates root dentin formation

Hertwig's root sheath

Mineralization pattern of mantle dentin

Globular

Membrane-bound structures where crystals first form

Matrix vesicles

Dentin lost after decalcification

Peritubular dentin

Main mass of dentin, retained after decalcification

Intertubular dentin

Hypomineralized crown dentin from failed calcospherite fusion

Interglobular dentin

Hypomineralized root layer adjacent to the CDJ

Granular layer of Tomes

Vitamin deficiency linked to interglobular dentin

Vitamin D

Excess element linked to interglobular dentin

Fluoride

Lines reflecting a 5-day change in collagen orientation

Von Ebner lines

Accentuated incremental lines from mineralization disturbance

Contour lines of Owen

Wide contour line marking birth

Neonatal line

Daily dentin deposition rate

4 µm

Empty tubules after odontoblastic process retraction from trauma

Dead tract

Tubules occluded with mineral, increases with age

Sclerotic dentin

Accepted theory of dentin sensitivity

Hydrodynamic theory

Disproven theory where odontoblasts act as pain receptors

Odontoblast receptor theory

What stimulates pulpal nerves in the hydrodynamic theory?

Tissue fluid movement

Inorganic content of dentin by weight

70%

Organic content of dentin by weight

20%

Water content of dentin by weight

10%

Mineral that makes dentin hard

Calcium hydroxyapatite

Main collagen type in dentin

Type I

Course of dentinal tubules

Sigmoid (S-shaped)

Branches of tubules at the periphery

Canaliculi

Sensitive junction between enamel and dentin

DEJ

Age-related result of continuous dentin deposition

Pulp recession

Tubule pattern in tertiary dentin

Irregular or absent

Dentin forms throughout life at the expense of

Pulp cavity

Dentin is softer than which tissue?

Enamel

Mechanical property of dentin

Hard but elastic

Tissue covering dentin in the root

Cementum

Tissue covering dentin in the crown

Enamel

Cells that form dentin

Odontoblasts

Collagen content of enamel

0%

Inorganic content of enamel by weight

90+%

Tissue chemically similar to dentin

Enamel

Dentin is harder than which two tissues?

Bone and cementum

Which tissue has larger crystallites: enamel or dentin?

Enamel

Signaling source that induces odontoblast differentiation

Inner enamel epithelium

Cells of the papilla that become odontoblasts

Undifferentiated mesenchymal cells

Thickness of the predentin layer

15–20 µm

Direction odontoblast cell body moves during dentin formation

Toward the pulp

Dentin type that forms before root completion

Primary dentin

Predentin plus calcium hydroxyapatite equals

Mineralized dentin

Dentin type formed without a predentin matrix

Tertiary dentin

Tubule region more closely packed

Near the pulp

Minor branches off main tubules

Microtubules

Secondary dentin tubules compared with primary

Less regular

Cause of dead tract formation

Trauma

Most common root location of sclerotic dentin

Apical third

Dentin that looks white next to a dead tract

Tertiary dentin

Dentin type lacking collagenous matrix

Peritubular dentin

Radiographically denser dentin type

Peritubular dentin

Incremental lines seen in enamel

Lines of Retzius

Incremental lines seen in dentin

Lines of Owen

Structures found in heterogeneous reparative dentin

Osteodentin and fibrodentin

Minor collagen types in dentin besides Type I

Types III and V

Tissue where lamina limitans lines the tubule

Dentin