Week 3

Question 1

Odontoblasts differentiate from embryonic 1) ___________ derived from the 2) __________ during the initial events of tooth
development

Answer 1

1) ectomesenchymal cells

2) cranial neural crest

Question 2

Odontoblasts are 1) post-_____ cells that share certain features with 2) ____ and _____ as static cell
populations; these cells are normally not replaced during the life of the organism

Answer 2

1) mitotic

2) neurons and myocardiocytes

Question 3

Odontoblasts function?

Answer 3

1. reciprocal induction of ameloblasts
2. secretion and synthesis
   
   • collagen TYPE ONE
   • growth factos TGFBs and NGF and BMP
3. sensory
4. defense

Question 4

with reciprocal induction of ameloblasts, the IEE elongates and secrets WHAT to induce odontoblasts differentiation from ectomesenchymal cells?

Answer 4

secreted TGF-1, bone morphogenic protein-2, insulin-like growth factor
* odontoblasts form dentin and retreat towards pulp… IEE now becomes ameloblasts secreting enamel

Question 5

What two daughter cells does ectomesenchymal cells make?

Answer 5

1) under the influence of IEE one will differentiate
into odontoblast

2) the second persists as
subodontoblastic mesenchymal cell or dental pulp stem cell

Question 6

Odontoblasts survival rate

• • Shallow cavity =
• • Moderate deep =
• • Deep cavity =

Answer 6

– Shallow cavity ( > 1 mm RDT): 100%

– Moderate deep (1-0.5 mm RDT): 89%

– Deep cavity (0.5-0.25 mm RDT): 83%

• < 0.25 mm RDT: 68% with severe pulpal inflammation

Question 7

Greatest reactionary dentin deposition occurs in shallow, moderate or deep cavities?

Answer 7

deep

Question 8

Reactionary dentine is

deposited by up-regulation?

Answer 8

of surviving odontoblast activity in response to a relatively mild stimulus, potentially including pro-inflammatory mediators

Question 9

Reparative dentinogenesis is more complex and

requires new?

Answer 9

odontoblast-like cell differentiation from stem/progenitor cells and subsequent up-regulated secretion in response to a relatively intense stimulus.

Question 10

During the innervation of human tooth pulp, odontoblasts express _____________, one of the multiple guidance cues that lead pioneering axons to innervate the dentin-pulp complex within each tooth cusp

Answer 10

semaphorin 7A

Question 11

peptides β-defensin-1 are bacteriocidal against?

Answer 11

G- bacteria

Question 12

peptides β-defensin-2 are induced by? bacteriocidal against?

Answer 12

induced by G– & S. mutans microorganisms via TLR4

* bacteriocidal against G-

Question 13

Inducible nitric oxide resulting from____ activation

Answer 13

TLR2

Question 14

nitric oxide resulting from TLR2 activation INHIBITS?

Answer 14

S. mutans growth

Question 15

TLR2 or TLR4 found in higher amounts on normal teeth?

Answer 15

TLR4