Biology and Histology of Pulp and PA Tissues

Question 1

what is a pulpal organ

Answer 1

central mass of a tooth consisting of soft tissue that is densely innervated by afferent fibers, sympathetic fibers, vascular structures, lymphatics and specialized cells such as odontoblasts and fibroblasts

Question 2

what cells are found in pulp and what is the most common cell type in pulp

Answer 2

fibroblasts- most common
odontoblasts

Question 3

what are the primary functions of the pulpal organ and describe each

Answer 3

• formative: odontoblasts- dentin and ameloblasts -enamel

Question 4

what are the secondary functions of the pulpal organ

Answer 4

supportive
- protection
- sensation
- defense
- repair

Question 5

what do fibroblasts arise from

Answer 5

undifferentiated ectomesenchymal cell

Question 6

what do fibroblasts do

Answer 6

elaborates type I and II collagen fibers and ground substance
- wound healing
- pulpal regeneration

Question 7

what do odontoblasts do

Answer 7

• unique to the pulp
• responsible for dentinogenesis
• amelogenesis
• produced collagen fiber and proteoglycan matrix which becomes mineralized

Question 8

where do odontoblasts processes extend into

Answer 8

tubules

Question 9

what nerves innervate the pulp

Answer 9

-trigeminal nerve V2 and V3 in maxillary and mandibular
- PM from mylohyoid
- cervical spinal C2 and C3

Question 10

IA block alone may provide _____

Answer 10

insufficient anesthesia

Question 11

are the nerves that supply dental pulp myelinated or not

Answer 11

both

Question 12

which fibers are the largest diameter in order of largest to smallest

Answer 12

A alpha > A beta> A gamma> A delta > C fibers

Question 13

what fibers are fastest to slowest

Answer 13

A alpha> A beta> A gamma> A Delta > C fibers

Question 14

which fiber is unmyelinated

Answer 14

C fibers

Question 15

describe A fibers

Answer 15

• low stimulation threshold, quicker response, pain characteristics are sharp and pricking

Question 16

describe C fibers

Answer 16

• high stimulation threshold
• slow in onset
• dull and aching and more diffuse less bearable pain

Question 17

what should you think with A fibers

Answer 17

acute pain maybe RP

Question 18

what should you think with C fibers

Answer 18

chronic damage, IP, pulpal pain

Question 19

what is Branstromms hydrodynamic theory

Answer 19

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

Question 20

what are the common etiologies of pulp irritation

Answer 20

• microbiological
• mechanical
• chemical
  -trauma

Question 21

the pulp is amazingly resilient if covered by at least ______

Answer 21

0.5mm of healthy dentin

Question 22

reasonable trauma to the pulp can be survived if____

Answer 22

bacteria are minimized or eliminated

Question 23

many of the etiologies of pulpal damage are ____

Answer 23

iatrogenic

Question 24

describe pulp polyp (hyperplastic pulpitis)

Answer 24

doesnt hurt but cant heal

Question 25

describe the response of dental pulp to aging

Answer 25

uniform deposition of tertiary dentin reducing the size of the pulp but retaining the general form as the tooth ages

Question 26

what is another name forcalcific metamorphosis

Answer 26

pulp sclerosis or dystrophic calcification

Question 27

what is calcific metamorphosis

Answer 27

- a combo of secondary or tertiary dentin formation in response to extensive and chronic injuries befoer the pulp became necrotic - no deposition unless pulp is vital

Question 28

what is the #1 threat to health of the dental pulp

Answer 28

caries

Question 29

how big are bacteria

Answer 29

0.2 - 5 um

Question 30

how big are tubules

Answer 30

50 um

Question 31

what are the most common causes of portals of assess of microbiological irritants

Answer 31

caries and leaking restoration

Question 32

what is the central goa of RCT obturation

Answer 32

to seal all portals of access

Question 33

what does cutting with insufficient coolant cause

Answer 33

- aspiration of odontoblasts into tubules - cooking of the pulp in its own juices - if beyond limits of repair = pulp necrosis

Question 34

what temperature does pulp necrosis occur at

Answer 34

10 degrees celsius

Question 35

what do mechanical irritants cause

Answer 35

- excessive air drying of exposed dentin: aspiration - application of desiccants: alcohol ,chloroform , cavi - pulp exposure

Question 36

what can mechanical irritants be

Answer 36

polishing - use of laser

Question 37

what does tertiary dentin do

Answer 37

- 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 it altered

Question 38

what layers tertiary dentin

Answer 38

fibroblasts

Question 39

what are external accidents cause by

Answer 39

falls and sports accidents

Question 40

what is internal trauma caused by

Answer 40

para- normal habits like bruxism

Question 41

what irritating or toxic elements can cause pulpal injury

Answer 41

- direct pulp cap or indirect pulp cap - disinfecting agents - acidic preparations - composites

Question 42

what is the diameter and velocity of conduction of A alpha fibers

Answer 42

- 12-20 um 70-120 m/sec

Question 43

what is the diameter and velocity of conduction of A beta fibers

Answer 43

- 5-12 um - 30-70 m/sec

Question 44

what is the diameter and velocity of conduction of A gamma fibers

Answer 44

- 3-6 um 15-30 m/sec

Question 45

what is the diameter and velocity of conduction of A delta fibers

Answer 45

- 1-5 um - 6-30 m/sec

Question 46

what is the diameter and velocity of conduction of C fibers fibers

Answer 46

- 0.4-1 - 0.5-2 m/sec

Question 47

what is the diameter and conduction velocity of A alpha fibers

Answer 47

12-20 um 70-120 m/sec