Histology Numbers

Question 1

Thichness of enamel in cusp tip or incisal edge

Answer 1

2.5mm

Question 2

Intiation of first permanent molar occur in …….

Answer 2

At 4 month IUL

Question 3

Intiation of permanent central incisors occur in…..

Answer 3

5 MIUL

Question 4

Intiation of 2nd premolars in ….

Answer 4

10 M after birth

Question 5

Intiation of second molar

Answer 5

1 Y after birth .

Question 6

Intiation of third molar in….

Answer 6

4 Year after birth

Question 7

Completly distengration of dental lamina at …

Answer 7

5 Y

Question 8

Enamel crystals ( width -thickness length

Answer 8

Width :70nm
Thichness 25nm
Length 160nm ( whole length of enamel )

Question 9

Number of enamel prism (at lower central - upper 6

Answer 9

L1: 5 million
U6 : 12000 million

Question 10

The ratio between inner ,outer enamel surface is ……

Answer 10

1:2

Question 11

The thichness of enamel prism at (ADJ- surface

Answer 11

AGJ: 3-4 micron
Surface: 8 micron

Question 12

Thickness of cross striations

Answer 12

4 Mm

Question 13

Extension of enamel tufts

Answer 13

From ADj to (1/3 -1/5) enamel thichness

Question 14

Thichness of apical foramen

Answer 14

.3 to 0.6 mm

Question 15

Thichness of cementum

Answer 15

At cervix: 20 -50 micro m
At apical third : 150-200 micro m

Question 16

Bone hydrocy apatites

Answer 16

Width : 50
Thickness: 8nm
Length : variable

Question 17

Ratio of collagenous protein

Answer 17

28 of organic

Question 18

Non collagenous protein ratio

Answer 18

5 %