histology dentin and pulp

3 types of dentin

primary, secondary, tertiary

when does the primary dentin form

before eruption

what 5 things does the primary dentin include?

mantle, interglobular, circumpulpal, peritubular, intertubular

when does the secondary dentin form?

after eruption

secondary forms _____ than primary and is ____ mineralized (more or less)

after, less

when is tertiary dentin formed

trauma

mantle is the ________ layer of dentin

outermost

what does the circumpulpal dentin surround?

the outer pulpal wall

secondary dentin forms after the development of the ______ foramen

apical

can dentin and pulp be viewed clinically if the gums are healthy?

no

why do you have to be careful when doing root canals or fillings on kids?

the pulp horns are higher

mineral level of enamel

96%

mineral level of dentin

70%

mineral level of cementum

65%

mineral level of alveolar bone

60%

what color is dentin

yellowish

dentin is less white than enamel because it's

less mineralized

dentin is more radio______ than enamel, but more radio______ than pulp

lucent, paque

dentin is slightly more ________ which allows for mastication without enamel fracture

elastic

dentinogenesis is the formation of

dentin

odontogenesis is the formation of

teeth

odontoblasts are cells that form

dentin

what stage of tooth development does the process of dental matrix/predentin occur?

apposition

dentin forms in _____

layers

Predentin matures into

dentin

predentin contains ____________ processes

odontoblastic

the predentin matures by forming _______

globules

mature dentin is aka

mantle

globules are areas of dentin that are

not fully formed yet

predentin is next to the ___ with ________ on the opposite side

dej, ameloblasts

the largest portion of the tooth's dentin is

circumpulpal

what happens to odontoblasts when you have a dentinal injury?

they die

interglobular dentin are areas that are less ________

mineralized

hypomineralization of dentin could be a result of ________ ________ or other medical issues

vitamin deficiency

true or false: sometimes less or more dentinogenesis occurs in one area than another

true

is it normal for dentin to sometimes pass the DEJ?

yes

what shape is the DEJ usually?

scalloped

if the dentinal tubules cross the other side of the dej, the patient may experience more ____________

sensitivity

the cell body of the odontoblastic processes are closer to the ______

pulp

what do the odontoblastic process and dentinal tubules have inside them? what does this cause?

fluid, pain/sensitivity

where are odontoblastic processes found?

within the dentinal tubules

Sclerotic dentin is a type of ______ dentin.

tertiary

when odontoblasts die and leave dead tracts in the dentin, they become access routes to pulp for ________ ________

microbial agents

injury to the dentin can be a result of (3)

caries, attrition, age

in sclerotic dentin, the hallow/vacant dentinal tubules become occluded by a mineralized substance like ________ dentin

peritubular

sclerotic dentin is a mechanism to _______ the _____

protect the pulp

if the holes of the dentinal tubules get occluded then

you cant sense anything

a dentist may apply composite restoration to seal ____ ______ which reduces ___________

open tubules, sensitivity

the imbrication lines of dentin are called "imbrication lines of _____ ______"

von ebner

neonatal lines are specific contour lines of _______ and are parallel or horizontal?

Owen

does dentin formation occur all at once or incrementally?

incrementally

which antibiotic can bind chemically to the hydroxyapatite of cementum and dentin? This causes _____

tetracycline, staining

is tetracycline staining intrinsic or extrinsic?

intrinsic

is tetracycline staining a sign of unhealthy teeth?

no

what are hypocalcified/ defective areas of dentin along the root surface called? (they are adjacent to cementum)

tomes granular layer

tomes granular layer may play a role in ____ _________

root sensitivity

the odontoblastic processes are surrounded by ______ ________ and are enclosed in dentinal ______.

dentin matrix, tubules

when dentinal tubules sometimes pass the DEJ and cross over into the enamel, they are called ______ or ________

spindles or tufts

when spindles cross over the DEJ it may increase ________

sensitivity

T or F: odontoblastic processes are essentially an extension of the cell body

true

how to reduce hypersensitivity (type of toothpaste, type of procedure)

sensodyne and sealants

caries in the dentin do not always equal pain, they only hurt once the decay starts to reach the _____

pulp

what pH does dentin start to demineralize?

6.8

more acidic= more ________________

demineralization

how can a dental hygienist accidentally remove the protective layers of cementum and dentin?

improper hand scaling

thermal/mechanical/chemical exposure to the teeth causes a _____ and _____ type of pain, but pain from caries/gingival infections is more ____ and _______

short and sharp, dull and chronic

How is saliva helpful?

helps remineralize the tooth

what 3 remineralization factors does saliva contain

fluoride, calcium, phosphate

what 3 antibacterials does saliva contain?

fluoride, chlorhexidine, xylitol

with increased age, what happens to the dentinal tubules?

they narrow

with age, the dentinal tubules get more _______, and the pulp chamber gets ______

narrow, smaller

the natural activity of cells ________ as we age

decreases

with age the pulp's ability to react to various stimuli with age _________

decreases

the pulp chamber has two sections which are

coronal and radicular

coronal pulp is found in the

crown

radicular pulp is found in the

root

Smaller extensions of coronal pulp into the cusps of posterior teeth are called

pulp horns

in a pediatric patient, the pulp horns are closer to the (top or bottom)

top

pulp horns are only found in anterior or posterior teeth

posterior

radicular pulp extends from the cervical area to the ______ of the ______

apex, root

the pulp gets smaller with age because the _______ is _______(increasing or decreasing) as a protective mechanism to the pulp.

dentin increasing

apical foramen is a hole at the tip of the ______ and is surrounded by layers of _________

root, cemuntum

what 4 things enter and exit the tooth through the apical foramen?

arteries, veins, lymphatics, nerves

true or false: even if the pulp is gone, the tooth can still be functional

true

if the apical foramen begins to close, it can lead to a ______ tooth

dead

is a dead tooth always painful?

no

with increased age, the apical foramen gets ______ in diameter

smaller

if theres more than one apical canal, the larger one is designated for the _______ foramen, and the lateral ones are called _________ canals

apical, accessory

accessory canals form when the _________ encounters a _____ ______ during formation of the _____.

HERS, blood vessel, root

what is the clinical importance of the pulp horns?? they are ______ in the crown for _____ (adults or children)

higher, children

where are dentin and pulp produced from?

dental papilla

difference in connective tissue of pulp and dentin

loose noncalcified, calcified

difference in vascularity of pulp and dentin

vascular, avascular

the outer layer of the dental papilla forms _____, and the inner layer/core forms the ______

dentin, pulp

Peritubule dentin surrounds the

dentinal tubules

5 functions of pulp

ISPVN

inductive, sensory, protective, vitality, nutritive

(inductive) the pulp interacts with the oral epithelium and initiates _____ ___________

tooth formation

how is the pulp protective

it forms the reparative dentin

4 zones of pulp

odontoblastic, cell-free, cell-rich, pulp core

what cells are the largest group in pulp

fibroblasts