Chapter 8 Midterm Questions Flashcards
Primary dentin is the major component of the crown and root and consists of _______ dentin
mantle
What develops after odontoblasts die (because of trauma or old age)?
dead tracts
Dentin is composed of what percentage of inorganic hydroxyapatite crystals
70%
Dentin is composed of what percentage of organic collagen fibers
20%
Dentin is composed of what percentage of water by weight
10%
True or False
With 20% less mineral than enamel, dentin is softer, although it is slightly harder than bone or cementum
True
What is the type of primary dentin first formed?
mantle dentin (deposited at first dentinoenamel junction)
True or False
Secondary dentin forms internally to primary dentin of the crown and root
True (develops after crown has come into clinical occlusal function and the roots are nearly completed)
The dentin is deposited more (slowly/rapidly) than primary dentin
slowly
True or False
The tubules of primary and secondary dentin are generally continuous unless the deposition of secondary dentin is uneven
True
True or False
As dentin is formed by odontoblasts, space is provided for the lengthening process of the odontoblast that moves pulp ward from the DEJ
True
What is the name of the dentinal matrix that immediately surrounds the dentinal tubule?
intratubular or peritubular dentin
Why is it called peritubular?
because it is a hyper mineralized collar surrounding the tubules
