EX2; Periodontium - Cementum Flashcards Preview

May14 Oral Histology > EX2; Periodontium - Cementum > Flashcards

Flashcards in EX2; Periodontium - Cementum Deck (26)
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1
Q

What are the three main functions of cementum

A

attachement
protection
adaptation (to the physiological forces of mastication

2
Q

What is the composition of cementum

A

45-50% organic

50-55% inorganic (but can vary)

3
Q

What makes up the organic component of cementum

A

90% collagen (90:10 type I to type III)
non-collagenous proteins
ground substance

4
Q

True or False

Cementum is not vascularized

A

True

5
Q

True or False

Cementum does remodel

A

False; it does not remodel

6
Q

What is the main difference between cementum and bone

A

cementum is secreted throughout life, but not normally resorbed

7
Q

Where is cementum the thinest/thickest

A
thinest = ~CEJ (vulnerable)
thickets = towards the root apex
8
Q

What are the different types of CEJ joints

A

overlap (60%)
butt against (30%)
gap (10%)

9
Q

Primary cementum is composed of what

A

acellular extrinsic fiber (AEFC)

10
Q

What does extrinsic refer to in talking about AEFC

A

the fact that the organic matrix of cementum is secreted by cementoblasts and PDL fibroblasts that do NOT become entrapped in the cementum

11
Q

Acellular extrinsic fiber cementum is considered to play the most important role in what

A

attachment

12
Q

These constitute the mineralized ends of the PDL fibers

A

Sharpey’s fibers

13
Q

This consists of collagen fibers oriented parallel to the surface of the cementum with no clear connection to the PDL

A

cellular intrinsic fiber cementum (CIFC); type of secondary cementum

14
Q

This comprises the bulk of secondary cementum

A

mixed fiber cementum

15
Q

What type of fibers does mixed fiber cementum contain

A

intrinsic (parallel)
extrinsic (perpendicular)
perpendicular plays the roll in attachment

16
Q

When is mixed fiber cementum secreted

A

after and more slowly than the initial wave of secondary cementum, more prominent apically

17
Q

Where is the secondary cementum most thick

A

in places in response to occlusal forces

18
Q

These were originally cementoblasts, entrapped in the mineralizing extracellular matrix

A

cementocytes

19
Q

True or False

Cementocytes are actively participating in synthesizing cementum

A

False; they are not

20
Q

The rate of cementum formation varies based upon what

A

environmental factors

21
Q

An increase in cementum production has been associated with what

A

attrition

periodontal disease accompanied by pronounced inflammation

22
Q

Continued deposition of cementum can cause the size of what to become progressively smaller

A

the apical foramen

23
Q

Where are the cementoblasts located

A

lying at the end of the PDL, their long axis parallel to the CEJ

24
Q

The outmost layer of cementum directly adjacent to the cementoblasts is sometimes unmineralized, and called what

A

cementoid

25
Q

These are similarly found in dentin and enamel, apparent in layers in the cementum

A

growth lines

26
Q

This is excessively large amounts of cementum deposition (around the root)

A

hypercementosis (relatively rare)

in the case study; the patient presented with gingival recession but no pain