periodontium

Question 1

what is the periodontium?

Answer 1

tissues surrounding and supporting the the teeth

Question 2

name the 3 periodontal tissues?

Answer 2

cementum
PDL
alveolar bone

Question 3

give 3 functions of the periodontium

Answer 3

. retain tooth in socket
. defence barrier
. resist masticatory load

Question 4

which structure separates body tissues from the oral environment?

Answer 4

junctional epithelium

Question 5

what structure covers root dentine?

Answer 5

cementum

Question 6

compare the structure of cementum to bone

Answer 6

. centrum has a linear lamellar arrangement whereas bone has a radial, cementum is avascular
. both have collagen matrix

Question 7

name the 2 types of cementum?

Answer 7

acellular and cellular

Question 8

compare cellular and acellular cementum

Answer 8

acellular:
. no cells, adjacent too dentine, 1st formed
cellular
. contains cementocytes, formed later, present in apical part of tooth and furcation regions

Question 9

which type of cementum is 1st formed?

Answer 9

acellular

Question 10

what are the hstolgogical classifications of cementum?

Answer 10

acellular extrinsic fibre cementum and cellular intrinsic fibre cementum

Question 11

which cementum contains sharpers fibres?

Answer 11

acellular extrinsic fibre cementum

Question 12

which cementum has no role in attachment?

Answer 12

cellular intrinsic fibre cementum

Question 13

alveolar bone is penetrated by nutrient cannals called?

Answer 13

volkmans canals

Question 14

what structure provides attachment for pdl/sharpeys fibres?

Answer 14

alveolar bone - lamina dura

Question 15

what are 2 functions of PDL?

Answer 15

attach tooth to jaw

transmit biting force to alveolar bone

Question 16

what does PDL contain?

Answer 16

cells
ecm
nerves
BVs

Question 17

which cells does PDL contain?

Answer 17

fibroblasts 
epithelial
osteoblats
cementoblasts 
defence cells

Question 18

what does ecm in PDL contains?

Answer 18

hyaluronate GAGs
glycoproteins
proteoglycans

Question 19

which 2 types of sensory nerves does the PDL contains?

Answer 19

mechanoreceptors (a beta and a delta)

nociceptors (a delta and c)

Question 20

where does blood supply to PDL originate?

Answer 20

inferior and superior alveolar arteries

palatine and lingual arteries

Question 21

whites the function of true PDL fibres?

Answer 21

connect tooth to bone at apical or alveolar crest

Question 22

what type of fibres are the principal fibres in true PDL

Answer 22

collagen type 1 and 2

Question 23

name the 5 PDL principal fibres in the alveoli-dental ligament

Answer 23

alveolar crest
horizontal
oblique
apical
interradicular (multirooted)

Question 24

name the PDL interdental ligament fibre

Answer 24

transeptal fibres

Question 25

what do PDL transeptal fibres connect?

Answer 25

tooth to tooth

Question 26

what do gingival fibres do?

Answer 26

hold gingiva firmly against tooth

Question 27

which type of fibres are gingival fibres?

Answer 27

collagen

Question 28

desmosomes and hemidesosomes are involved in connecting junctional epithelium to tooth, compare the function of both

Answer 28

desmosomes - attach adjacent cells | hemidesmosomes - attach cells to epithelium (adhesion)

Question 29

what is the connection point between 2 teeth called?

Answer 29

col

Question 30

what is the advantage of the orientation of oblique fibres?

Answer 30

biting forces transmitted and dissapated to bone

Question 31

where is acellular centrum found?

Answer 31

all parts of root

Question 32

where is centrum thickest?

Answer 32

apex

Question 33

which structures pass through gaps in inner cortical plate of alveolar bone?

Answer 33

BVs passing through nutrient canals

Question 34

are collagen fibres straight or wavy and why?

Answer 34

wavy - allow small amount tooth movement

Question 35

what is the main cell type in PDL?

Answer 35

fibroblast

Question 36

fibroblast funciton

Answer 36

form and degrade collagen and form ground substance of PDL

Question 37

which side of PDL are fibre bundles larger?

Answer 37

bone side

Question 38

which side of pdl are fibres closer together?

Answer 38

cementum side

Question 39

which fibre group are seen in interdental region and not labial or lingual aspects of periodontium?

Answer 39

transeptal

Question 40

which fibres seen on lingual and labial aspects of periodontium endnote interdental regions?

Answer 40

alveolar crest

Question 41

fibres not attached to bone?

Answer 41

transeptl, gingival

Question 42

type of epithelium in gingiva?

Answer 42

strat squamous

Question 43

oral epithelium vs sulcular

Answer 43

sulcular thinner and not keratinised