L5-Dentin Flashcards
Describe how the three components of Dentin, collagen 1, Non-collagenous proteins, and Hydroxyapatite, come together to form dentin?
The Collagen type I fibers form the ‘scaffold’ with bound and unbound Non-collagenous proteins (NCPs) that regulate deposition of HAP mineral.
Why is the unique elastic quality of dentin essential for proper tooth function, biomechanics?
Provides flexibility and prevents enamel fracture.
Dentinogenesis dysplasias happens because collagen type I not properly formed, dentinogenesis goes wrong, what are the physical characteristics of these teeth?
Gray-blue/yellow brown teeth with loose mineralization in dentin. Teeth break easily. Often just ground nubs or cracked at or near gumline.
What is tertiary dentin? Why does it differ from primary or secondary dentin?
Tertiary dentin is reparative dentin and is deposited as a response to stimuli (attrition, caries, restoration). It differs b/c when laid down in response to decay it is not well organized. There are no tubules, therefore, it’s more like scar tissue than actual dentin.
Where do the odontoblasts originate from in Dentinogenesis?
The ectomesenchyme layer of dental papilla. Forms through the process of odontogenesis.
What mixture of two products do odontoblasts secrete to form the MANTLE PREDENTIN?
What is a function of mantle predentin?
Collagen I and III fibers. Mostly collagen I. Collagen III is generally a bad thing and is found mainly in mantle predentin.
Mantle predentin is less mineralized, therefore, it is softer and provides cushion.
Where are the two patterns of CALCIFICATION, linear and globule, found in dentin?
Linear is found in circumpulpal (primary and secondary dentin) (strongest).
Globule is found in mantle dentin (provides strength).
The two types of dentin mineralization are, Heterogeneous nucleation and matrix vesicle-dependent. Where does each happen?
Heterogeneous nucleation (linear) happens in circumpulpal dentin. Matrix vesicle-dependent (globular) happens in mantle dentin
