Cementum

Question 1

What does cementum do?

Answer 1

Covers root dentine (crown dentine covered by enamel)

Question 2

What is the lamellar arrangement in cementum?

Answer 2

linear

Question 3

What is the structure of cementum similar to?

Answer 3

bone

Question 4

What lays down cementum?

Answer 4

cementocytes

Question 5

What are the 2 types of cementum?

Answer 5

acellular
cellular

Question 6

What are the characteristics of acellular cementum?

Answer 6

• No cells within
• Usually adjacent to dentine
• First formed (primary cementum)

Question 7

Which type of cementum is primary cementum?

Answer 7

acellular cementum

Question 8

What are the characteristics of cellular cementum?

Answer 8

• Contains cementocytes
• Later formed (secondary cementum)
• Present in the apical part of the root and in furcation (between two roots) regions

Question 9

Which type of cementum is secondary cementum?

Answer 9

cellular

Question 10

What is the furnication region?

Answer 10

the area between the roots of posterior teeth

Question 11

What are Sharpey’s fibres and what do they do?

Answer 11

Periodontal fibres - attaches tooth to soft tissue
PDL to cementum/alveolar bone

Question 12

What is acellular extrinsic fibre cementum?

Answer 12

• Collagen fibres from PDL (Sharpey’s fibres)
• Equivalent to primary acellular cementum
• Present on cervical 2/3 of roots

Question 13

What is cellular intrinsic fibre cementum?

Answer 13

• No Sharpey’s fibres
• Intrinsic collagen fibres parallel to the surface
• Equivalent to secondary cellular cementum
• No role in tooth attachment

Question 14

What makes up the periodontium?

Answer 14

alveolar bone
cementum
periodontal ligamentum
gingiva

Question 15

What is the content of cementum?

Answer 15

65% inorganic hydroxyapatite
23% organic
12% water

Question 16

What is the arrangement of acellular and cellular cementum?

Answer 16

ceullar cementum usually is formed on top of acellular