Exam 3 - Dentin Pulp Complex I Colombo Flashcards
Mineralized protective component of the tooth is called:
Enamel
Mineralized structural component of the tooth is called:
Dentin
Main cellular component of the tooth is:
Pulp
Dentin composition is highly analogous to ____, but:
Bone; but slightly different composition and highly different anatomy
The crown is covered by:
Enamel
The root is covered by:
Cementum
Dentin composition by weight
- inorganic material: 70%
- organic material: 20%
- water: 10%
Dentin composition by volume
- inorganic material: 45%
- organic material: 33%
- water: 22%
Inorganic material in dentin (and enamel, bone, cementum) is called:
Hydroxyapatite
The water in dentin is also termed:
Physiological fluid
What is the chemical formula for hydroxyapatite?
Ca5(PO4)3(OH)
x2 per crystal unit cell
Hydroxyapatite is effectively a:
Calcium phosphate crystal
___ can replace the OH in hydroxyapatite
Fluoride (creates fluorapatite)
Besides fluoride, what other ions can replace the OH of hydroxyapatite?
- zinc
- magnesium
Hydroxyapatite crystals are arranged in _____
Rectangular plates
True or false: dentin is somewhat harder than bone
True (Knoop number 68, bone is 50)
True or false: enamel is much harder than dentin or bone
True - Knoop number 343
Why is enamel much harder than dentin?
Due to how the HA is arranged
Organic material of dentin is made of:
- 90% collagen
- 10% Non-collagenous proteins
Main type of collagen found in dentin
Collagen type 1 (also some type 3 and type 5)
The organic material secreted by dentin creates the _____ upon which HA is laid down
fibrillar collagen scaffold
Dentin specific proteins (in the organic component)
- Dentin matrix protein 1 (DMP-1)
- Dentin Sialophosphoprotein (DSPP)
DSPP is further cleaved by ____ into:
BMP-1; DSP, DPP, DGP
DSP is a ____ expressed in ____
proteoglycan; dentinal tubules
____ may act to prevent mineralization in tubules
DSP
DGP is a _____ and may have a role in ____ (unknown)
Glycoprotein; biomineralization
DPP binds ____ to initiate HA formation and is attached to ____
Lots of Ca2+; collagen
DPP is attached to ____
Collagen
____ is not thought to be glycosylated
DPP
____ is located on the N terminus of the DSPP protein
DSP
____ is located on the C terminus of the DSPP protein
DPP
Defects in DSPP can cause:
Dentinogenesis imperfecta Types II and III
Type 1 Dentinogenesis results from:
Osteogenesis imperfecta (defect in type 1 collagen)
Both type 1 and type 2 dentinogenesis imperfecta cause:
Pulp chambers to be filled with abnormal dentin
True or false: Type II Dentinogenesis imperfecta is associated with osteogenesis imperfecta
False (Type 1 can result from OI)
Type III Dentinogenesis imperfecta is associated with:
- Enlarged pulp chambers
- hypo-mineralization
Type III dentinogenesis imperfecta is caused possibly due to:
Failure of DSPP expression
Dentin is synthesized by _____
Odontoblasts
What lines the pulp chamber?
Odontoblasts
Odontoblasts are ____ cells which extend _____ into the dentin through tubules
Polarized; cellular projections
The dentin-pulp complex arises from:
Dental papilla
Initial differentiation of dentin formation occurs after:
Critical interaction with the inner enamel epithelium
When odontoblasts first differentiate, they fill the ___ zone between the ____ and ____
Acellular; IEE and dental papilla
Vascular support arises from:
Dental papilla