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Flashcards in periodontium Deck (43)
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1
Q

what is the periodontium?

A

tissues surrounding and supporting the the teeth

2
Q

name the 3 periodontal tissues?

A

cementum
PDL
alveolar bone

3
Q

give 3 functions of the periodontium

A

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

4
Q

which structure separates body tissues from the oral environment?

A

junctional epithelium

5
Q

what structure covers root dentine?

A

cementum

6
Q

compare the structure of cementum to bone

A

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

7
Q

name the 2 types of cementum?

A

acellular and cellular

8
Q

compare cellular and acellular cementum

A

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

9
Q

which type of cementum is 1st formed?

A

acellular

10
Q

what are the hstolgogical classifications of cementum?

A

acellular extrinsic fibre cementum and cellular intrinsic fibre cementum

11
Q

which cementum contains sharpers fibres?

A

acellular extrinsic fibre cementum

12
Q

which cementum has no role in attachment?

A

cellular intrinsic fibre cementum

13
Q

alveolar bone is penetrated by nutrient cannals called?

A

volkmans canals

14
Q

what structure provides attachment for pdl/sharpeys fibres?

A

alveolar bone - lamina dura

15
Q

what are 2 functions of PDL?

A

attach tooth to jaw

transmit biting force to alveolar bone

16
Q

what does PDL contain?

A

cells
ecm
nerves
BVs

17
Q

which cells does PDL contain?

A
fibroblasts 
epithelial
osteoblats
cementoblasts 
defence cells
18
Q

what does ecm in PDL contains?

A

hyaluronate GAGs
glycoproteins
proteoglycans

19
Q

which 2 types of sensory nerves does the PDL contains?

A

mechanoreceptors (a beta and a delta)

nociceptors (a delta and c)

20
Q

where does blood supply to PDL originate?

A

inferior and superior alveolar arteries

palatine and lingual arteries

21
Q

whites the function of true PDL fibres?

A

connect tooth to bone at apical or alveolar crest

22
Q

what type of fibres are the principal fibres in true PDL

A

collagen type 1 and 2

23
Q

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

A
alveolar crest
horizontal
oblique
apical
interradicular (multirooted)
24
Q

name the PDL interdental ligament fibre

A

transeptal fibres

25
Q

what do PDL transeptal fibres connect?

A

tooth to tooth

26
Q

what do gingival fibres do?

A

hold gingiva firmly against tooth

27
Q

which type of fibres are gingival fibres?

A

collagen

28
Q

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

A

desmosomes - attach adjacent cells

hemidesmosomes - attach cells to epithelium (adhesion)

29
Q

what is the connection point between 2 teeth called?

A

col

30
Q

what is the advantage of the orientation of oblique fibres?

A

biting forces transmitted and dissapated to bone

31
Q

where is acellular centrum found?

A

all parts of root

32
Q

where is centrum thickest?

A

apex

33
Q

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

A

BVs passing through nutrient canals

34
Q

are collagen fibres straight or wavy and why?

A

wavy - allow small amount tooth movement

35
Q

what is the main cell type in PDL?

A

fibroblast

36
Q

fibroblast funciton

A

form and degrade collagen and form ground substance of PDL

37
Q

which side of PDL are fibre bundles larger?

A

bone side

38
Q

which side of pdl are fibres closer together?

A

cementum side

39
Q

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

A

transeptal

40
Q

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

A

alveolar crest

41
Q

fibres not attached to bone?

A

transeptl, gingival

42
Q

type of epithelium in gingiva?

A

strat squamous

43
Q

oral epithelium vs sulcular

A

sulcular thinner and not keratinised