Lec 3

Question 1

necrosis travels which direction

Answer 1

coronal to apical

Question 2

what is the pulpal organ

Answer 2

central mass of tooth made of soft tissue, sensory innervations vessels/lymphactics
odontoblasts and fibroblasts

Question 3

most common cell in pulp?

Answer 3

fibroblasts

Question 4

primary function of pulp?

Answer 4

formative: odontoblasts form dentin
ameloblasts form enamel

Question 5

secondary functions of pulp?

Answer 5

support, protection, sensation, defense, repair

Question 6

what are fibroblasts?

Answer 6

most common cell in pulp, basic cell in all CT
arise from ectomesenchymal cells
form type I and III collagen and ground substance
important for regeneration in wound healing

Question 7

what are odontoblasts?

Answer 7

cell in pulp responsible for dentinogenesis
also important in amelogenesis
produce collagen fibers and proteoglycan matrix (become mineralized dentin)
processes extend into dentin tubules

Question 8

when does sclerotic dentin form?

Answer 8

when bacteria invade the pulp

Question 9

how is tertiary dentin formed differently

Answer 9

formed by fibroblasts in response to trauma
-has no dentinal tubules

Question 10

what is the Hydrodynamic Theory for tooth sensitivity

Answer 10

anything that causes movement of the fluid in the dentinal tubules causes pain/sensitivity in the pulp

Question 11

what is the lamina dura

Answer 11

cortical bone around tooth, thin layer
white line on radiograph

Question 12

when does primary dentin form?

Answer 12

as the roots of teeth develop, young patients

Question 13

when does secondary dentin form

Answer 13

after tooth eruption

Question 14

what happens to the pulp as we age

Answer 14

secondary dentin deposition as we age
reduces the size of the pulp uniformly, but retains the general form of the pulp
(tertiary dentin will change shape of pulp!)

Question 15

what is pulp canal obliteration PCO?
(also called calcific metamorphosis)

Answer 15

Pulp sclerosis, a combo of secondary and tertiary dentin formation in response to chronic injury.
Occurs before pulp becomes necrotic, must be vital to occur.
Canal is blocked, refer to advanced endo

Question 16

what are the 4 common etiologies of pulp irritation?

Answer 16

microbiological
mechanical
chemical
trauma

Question 17

what amount of dentin must cover the pulp to remain healthy

Answer 17

0.5 mm of dentin covering pulp keeps it healthy

Question 18

many etiologies of pulp are what type of cause?

Answer 18

iatrogenic (bur heating up pulp)

Question 19

what is the #1 cause of pulp irritation?

Answer 19

microbiological
dental caries is the #1 threat to the pulp

Question 20

what are the portals of access for MO to enter the pulp (5)

Answer 20

caries/leaking restoration (most common!)
cracked or fractured teeth
cemental defect at CEJ
open dentinal tubules
perio invasion into apex (deep pocket)

Question 21

what are some examples of mechanical irritation of the pulp

Answer 21

iatrogenic:
cutting w/o coolant
aspiration of odontoblasts into tubules (occurs when dentin overheats)
PULP CANNOT TOLERATE HEAT!! (10 degrees)
excessive drying w/ air
dessicants (alocohol, chloroform)
polishing
pulp exposure
use of laser

Question 22

trauma to the pulp can include?

Answer 22

external: falls and sports accidents
internal: habits like bruxism

Question 23

if the pulp is vital, what will Pt feel during cold testing?

Answer 23

pain! Vital pulp still has sensitivity
if pain lingers, sign that RC is needed
no pain = necrotic pulp

Question 24

when is tertiary dentin deposited?

Answer 24

deposited over area of injury by fibroblasts
attempt to repair, protect, or insulate pulp from more injury
form/shape of pulp is changed