Periodontium, Cementum, Alveolar Bone

Question 1

arrangement of principal fibers that support the teeth

Answer 1

periodontal ligament

Question 2

the periodontal ligament is located between the ____ and the ______ ____.

Answer 2

cementum, alveolar bone

Question 3

typical shape of the periodontal ligament

Answer 3

hourglass

Question 4

how wide is the periodontal ligament?

Answer 4

approximately 0.15-0.25 mm

Question 5

the periodontal ligament is _____ at the center of the root

Answer 5

narrow

Question 6

when the periodontal ligament is not in function, it is…

Answer 6

thinner, disorganized

Question 7

when the periodontal ligament is in over function, it is…

Answer 7

thick, wide PDL

Question 8

in terms of periodontal ligament thickness, is the PDL widest at the mesial or the distal?

Answer 8

distal

Question 9

true or false? the PDL progressively decreases with age

Answer 9

true

Question 10

true or false? the PDL is always in a state of remodeling

Answer 10

true

Question 11

6 principal group fibers of the PDL

Answer 11

alveolar crest, horizontal, oblique, apical, interradicular, transseptal

Question 12

alveolar crest fibers run in _____ direction, counterbalance ____ thrust

Answer 12

apical, coronal

Question 13

Horizontal fibers run in _______ direction, resist _____ pressure

Answer 13

horizontal, lateral

Question 14

oblique fibers run in the ______ direction, resist _____ forces

Answer 14

oblique, vertical/apical

Question 15

which PDL fibers cover 80-85% of the cementum?

Answer 15

oblique fibers

Question 16

apical fibers are at the ____ of the root, resist ____ forces and removal of tooth from socket

Answer 16

apex, tilting

Question 17

interradicular fibers present in the ______ (only present in ___-rooted teeth), resist ____ forces

Answer 17

furcations, multi, tilting

Question 18

terminal ends of principal fibers (in bone AND cementum)

Answer 18

Sharpey’s fibers

Question 19

the purpose of Sharpey’s fibers are to help maintain ____ because of attachment in ___ and _____.

Answer 19

support, bone, cementum

Question 20

true or false? Fibroblasts only have a “building” function (“blast” activity only)

Answer 20

false. Fibroblasts have both “blast” (building up) and “clast” (destruction) functions

Question 21

cells that generate cementum; cells that degenerate cementum

Answer 21

cementoblasts, cementoclasts

Question 22

cells that generate bone; cells that degenerate bone

Answer 22

osteoblasts; osteoclasts

Question 23

primary functions of the periodontal ligament

Answer 23

supportive, nutritive, formative, resorptive, sensory

Question 24

composition of cementum: ___% organic, ___% inorganic

Answer 24

50-55% organic, 45-50% inorganic

Question 25

functions of cementum

Answer 25

anchor for Sharpey's fibers, covers dentin, compensates for tooth wear/continual eruption

Question 26

CEJ types __% cementum overlaps enamel __% cementum and enamel do not meet __% cementum and enamel meet end-to-end

Answer 26

60, 10, 30

Question 27

``` CELLULAR CEMENTUM ____ half Less _____ ____ Thinner or thicker? More/less calcified than acellular? ________ present Width increase with age? T/F? ```

Answer 27

``` Apical Sharpey’s fibers Thicker Less calcified Cementocytes True, width DOES increase with age ```

Question 28

``` ACELLULAR CEMENTUM ____ half Mainly ______ _____ Thinner or thicker? More _____ No ______ present Width does not increase with age? T/F? ```

Answer 28

``` Coronal Sharpey’s fibers Thinner Calcified Cementocytes False, it does not change in width w/ age ```

Question 29

formation of cementum on the root surface (blast cells)

Answer 29

deposition

Question 30

deposition of cementum ___ the PDL space

Answer 30

maintains

Question 31

removal of cementum on root surfaces (clast cells)

Answer 31

resorption

Question 32

exposed cementum can lead to...

Answer 32

hypersensitivity

Question 33

periodontal disease process destroys ____ and alters _____

Answer 33

attachment, cementum

Question 34

toothbrush abrasion ____ cementum

Answer 34

destroys

Question 35

true or false? the cementum cannot have a caries lesion

Answer 35

false, it can

Question 36

____ can cause exposure of cementum, which can lead to sensitivity, periodontal disease, and cemental caries.

Answer 36

recession

Question 37

spaces where the root fits into (tooth socket)

Answer 37

alveoli

Question 38

all bone

Answer 38

alveolar bone/alveolar process

Question 39

bone adjacent to the root

Answer 39

alveolar bone proper

Question 40

other names for alveolar bone proper

Answer 40

cribriform plate, lamina dura

Question 41

all other bone (including cortical plates/bones, cancellous bone)

Answer 41

supporting alveolar bone

Question 42

dense fibrous CT that attaches gingiva to bone, contains osteoblasts, cannot be seen clinically

Answer 42

periosteum

Question 43

compact bone is also called...

Answer 43

cortical plates/bone

Question 44

spongy bone is also called...

Answer 44

cancellous bone

Question 45

composition of bone 65% inorganic _____ 35% organic ___ and ___

Answer 45

hydroxyapatite, fibers and cells

Question 46

shape of bone follows position of ___ _____ and ___ of roots

Answer 46

tooth contacts, contour

Question 47

anterior teeth bone morphology; posterior teeth bone morphology

Answer 47

``` anteriors = peaked posteriors = blunted ```

Question 48

function of alveolar bone

Answer 48

supports entire dentition, pathway for nutrients, deposition to compensate for continuous tooth eruption/wear

Question 49

bony defect that is a cleft in the bone

Answer 49

dehiscence

Question 50

bony defect that is a hole or window in bone

Answer 50

fenestration

Question 51

increased occlusal function leads to...

Answer 51

increased bone density

Question 52

decreased occlusal function leads to...

Answer 52

decreased bone density

Question 53

types of tissue from highest hydroxyapatite composition to lowest

Answer 53

enamel, dentin, bone, cementum

Question 54

causes of resorption

Answer 54

occlusal trauma, orthodontic movement, malaligned teeth, cysts/tumors, replanted teeth, periodontal disease

Question 55

what is hydroxyapatite composed of?

Answer 55

calcium, phosphate

Question 56

shape of alveolar crest: height is ____ ____ to the CEJ

Answer 56

1-2mm apical