L2 cementum and alveolar bone

Question 1

where is cementum thickest on the tooth ?

Answer 1

on distal surface (due to mesial drift over time ) and in the apical 3rd/ furcationareas

Question 2

composition of cementum :

Answer 2

45% -50% inorganic
50-55% organic

Question 3

cells of cementum :

Answer 3

cementoblasts
cementoclasts
cementocytes
periodontal fibroblasts

Question 4

classifications of cementum based on the origin of collagenous fibrils

Answer 4

intrinsic fibers: formed due to cementoblast activity

extrinsic: incorporations of PDL fibers

Question 5

list schroeders classification of cementum :

Answer 5

-Acellular afibrillar cementum : no cells no fibers , only mineralized ground substance (coronal cementum )

-Acellular extrinsic fiber cementum: composed entirely of Sharpe’s fibers

-cellular intrinsic:
fills resorption lacunae

-intermediate cementum: poorly defined zone near CEJ , contains cellular remnants of Hertwig’;s epithelial root sheath embedded in calcified ground substance

-cellular mixed stratified cementum :
contains both intrinsic and extrinsic fibers , may also contain cells

-coproduct of cement oblasts and fibroblasts (apical 3rd , apices , furcation area)

Question 6

what type of cementum is found in the coronal portion ?

Answer 6

acellular afibrillar cementum

Question 7

what type of cementum is found in the cervical 3rd of roots?

Answer 7

Acellular extrinsic fiber cementum

Question 8

what type of cementum is found in the apical 3rd , apicies , furcation area

Answer 8

cellular mixed stratified cementum

Question 9

which type of cementum fills the resorbtion lacunae

Answer 9

cellular intrinsic fiber cementum

Question 10

what type of cementum contains remenant sof hertwigs epithelial rooth sheath ?

Answer 10

intermediate cementum

Question 11

what are the differences between acellular and cellular cementum ?

Answer 11

acellular cementum’s border with dentine is not well demarcated (cellular cementum’s border is )

acellular cementum development is slower with incremental lines closer together and NO precementum layer while cellular cementum has a pre cementum layer

Question 12

difference between cementum and bone :

Answer 12

-cementum is avascular

-cementum has a minor ability to be remodeled
- more resistant to resorption

-lacks neural component

• contains unique proteoglycans
• less mineralized than bone

Question 13

organic/inorganic content of bone :

Answer 13

65% inorganic , 35% organic (89% collagen , 11% non collagenous)

Question 14

what does the interdental septum consist of?

Answer 14

cancellous bone bordered by cribiform plate and facial and lingual cortical plates (average distance between crest of ridge and CEJ 1.08

-increase with age