dentin essentials Flashcards
dentin location
in crown and root
dentin structure
tubular - microcanals radiate from dental pulp to enamel
dentin color
yellow
percentage mineralized inorganic substrates - calcium hydroxyapatite
65-70%
percentage organic substrates - collagenous protein
20-25%
percentage bound water
10%
Tomes fiber
vital tissue; cytoplasmic cell process
odontoblast process (an extension of an odontoblast- located in the dentinal tubules)
odontoblast
vital tissue; innervation to pulp
types of nerve fibers
myelinated A-fibers
unmyelinated C-fibers
Tomes layer
peripheral layer
cytoplastic process
Hyaline of Hopewell-Smith
clear layer between Tomes layer and cementum
cementum composition
45-50% inorganic (hydroxyapatite)
5-55% organic and water (collagen and proteoglycans)
cementum
thin layer (30-200 micrometers) of bonelike
material covering root surfaces
softer than enamel and dentin
fibers of periodontal membrane-ligament are connected to cementum
Lines of Owen
disturbance during mineralization
loss of cementum
exposed dentin
dentin tubules
primary curvature & secondary curvature
result from movement of odontoblasts during development
primary curvature
s-shaped
secondary cuvature
jagged or wrinkled texture
s-shaped
tooth crown
straighter path of tubules
root of tooth
primary dentin
most prominent dentin
lies between the enamel and pulp chamber starting at the dentinoenamel junction
mantle-dentin
the first formed dentin by odontoblast differentiation; it is located in both the crown underlying the DEJ and the root of the tooth
circumpulpal dentin
remaining bulk of primary dentin; collagen fibers narrower and thicker than M-D; greater mineralization than M-D; compact arrangement of fibers
secondary dentin
all dentin formed after root formation is completed (not due to trauma or dental pathology) - closest to pulp (visible on dental radiographs)
forms at slower rate than primary dentin but grows incrementally but unequally