biology and histology of the pulp and PA tissues

Question 1

DST, seen with?

Answer 1

draining sinus tract, seen with necrotic pulp/ChronicPA abseces

Question 2

main pulp components

Answer 2

conn tissues with fibroblasts, odontoblasts and osteoblasts

Question 3

can pulp defend?

Answer 3

Yes

Question 4

when does pulpal defense fail, leads to?

Answer 4

bacterial invasion, leads to inflam and necrosis

Question 5

what is the direction of usual bacterial invasion

Answer 5

coronal to apical

Question 6

Pulpal organ defined
cells? strucutres?

Answer 6

Central mass of a tooth consisting of soft tissue that is densely innervated by afferent (sensory) fibers, sympathetic fibers, vascular structures, lymphatics and specialized cells such as odontoblasts (characteristic cells of pulp) and fibroblasts (most
common/prevalent cell type in pulp)

Question 7

Primary Function of pulp?
e

Answer 7

Formative:
odontoblasts – dentin (with dental epithelium)
ameloblasts – enamel

Question 8

secondary pulpal functions

Answer 8

Supportive, Protection, Sensation, Defense, Repair

Question 9

Fibroblast arises from_______________

Answer 9

Fibroblast arises from undifferentiated ectomesenchymal cell

Question 10

most prevalent cell in pulp/ basic cell of all conn tissue

Answer 10

fibroblast

Question 11

function of fibroblasts

Answer 11

secrete type 1 and 3 collagen and ground substance

Question 12

fibroblasts important in which functions

Answer 12

wound helaing and pulpal regeneration

Question 13

Odontoblast
responsible for? also plays a role in?
produces?
processes extend into?

Answer 13

Cell unique to the pulp
–Responsible for dentinogenesis
–Important in amelogenesis
–Produces collagen fiber and proteoglycan matrix which becomes mineralized
–Processes extend into tubules, cell present in the pulp

Question 14

Answer 14

dentinal tubules with odontoblasts

Question 15

Answer 15

dentin
predentin
odontoblast layer

Question 16

tubule destruction progression

Answer 16

sclerosis may occur to block bac
tracts die
tertiary dentin formed by fibroblasts to block off tubules

Question 17

pulp chamber size with age

Answer 17

will decrease due to secondary dentin making endo treatment more difficult

Question 18

response of pulp to injury

Answer 18

TERTIARY (REPARATIVE) DENTIN is deposited over time in the immediate area of the injury
by fibroblasts in an attempt to repair, protect or insulate the pulp from further injury.
General FORM of PULP is altered.

Question 19

Branstromm’s“Hydrodynamic Theory”

Answer 19

Anything that causes movement of the fluid w/in the dentinal tubules causes pain in the pulp (hot/cold)
fluid movement moves nn fibers to cause pain
removal=no pain is good, removal with pain may indicate RCT

Question 20

dental pulp anatomy components

Answer 20

Question 21

lamina dura

Answer 21

cortical bone of the alveolar bone, appears more radiopaque

Question 22

odontoblasts primary dentin/ tooth formation

Answer 22

Question 23

pattern of deposition of secondary dentin

Answer 23

uniform, reduces the general size of the pulp but retains general form as the tooth matures

Question 24

Answer 24

bacteria entering through the tubules, bacteria are much smaller in diameter allowing for this

Question 25

what cells form tertiary dentin

Answer 25

fibroblasts

Question 26

Answer 26

microabscess on the left and tertiary dentin formation

Question 27

second response of the the pulp to aging and injury

Answer 27

Calcific Metamorphosis
Pulp sclerosis or Dystrophic calcification=PCO: pulp canal obliteration
•Probably a combination of 2ndary and Tertiary dentin formation in response to extensive and chronic injuries before the pulp became necrotic. (no deposition unless pulp is vital)
•This canal is not negotiable by normal means – Refer – MICROSCOPE, CBCT!

Question 28

PCO only related to what factor

Answer 28

pt age

Question 29

common etilogies of pulpal irritation
many of these are.

Answer 29

microbiological = primary cause
mechanical
chemical/ trauma (can allow bac to enter)
many of these can be iatrogenic

Question 30

pulp resilience

Answer 30

The pulp amazingly resilient if covered by at least .5mm of healthy dentin. Reasonable trauma can be survived if bacteria are minimized or eliminated.

Question 31

1 threat to pulp health

Answer 31

caries

Question 32

presence of bacteria and pulpal injury, rat experiment

Answer 32

The #1 cause of pulpal injury
Kakehashi exposed pulps of germ free and conventional rats to their own flora. The gnotobiotic rats did not develop pulpal or periradicular lesions.*
Without MO & their products, LEOs (Lesions of Endodontic Origin) do NOT occur

Question 33

acute pulpitis histology

Answer 33

bacteria present with pus/ PMN

Question 34

cracks in teeth

Answer 34

can allow bac to advance to the pulp and cause infection
may not be seen radiographically

Question 35

Portals of ACCESS” of microbiological irritants
-most common cause?

Answer 35

cracks/ tooth fracture
Caries/leaking Restoration (Most common Causes)*
Exposed lateral or accessory Canals
CEJ defects
open tubules (bac=.2-.5um, tubule=50um)
initial pocket allowing invasion at apical foramen (uncommon)

Question 36

Mechanical Irritants, example

Answer 36

Most operative procedures are accompanied by significant opportunity for
iatrogenic and irreversible damage to the pulp.
•CUTTING WITH INSUFFICIENT COOLANT CAUSES> Aspiration of odontoblasts into
tubules
•If beyond limits of repair = Pulp Necrosis. 10ºC

Question 37

aspiration of odontoblasts mechanisms

Answer 37

can be due to exccessive heating

Question 38

how should we dry dentin

Answer 38

cotton pellet not air

Question 39

types of trauma

Answer 39

EXTERNAL: Falls & Sports Accidents
INTERNAL: Para-Normal Habits (Bruxism)

Question 40

perio pockets may allow for?

Answer 40

bac invasion thru the apical foramen

Question 41

with bac present, what necrosis may occur in the pulp?

Answer 41

coagulative necrosis