Differences between primary and permanent

Question 1

How many teeth are in primary dentition?

Answer 1

20

Question 2

When does the first tooth appear?

Answer 2

6th month

Question 3

When have all the primary teeth erupted?

Answer 3

24-36th month
(2-3years)

By the 36th month all the primary teeth have
completely erupted and are in occlusion.

Question 4

Main functions of the primary dentition? (5)

Answer 4

• cut food
• keep space for permanent dentition
• stimulate growth
• enable fonation
• esthetic

Question 5

Differences between primary and permanent dentition are located at..: (3)

Answer 5

• crown
• roots
• pulp chamber

Question 6

The predominant diameter for primary dentition versus permanent? What aspect do the teeth have

Answer 6

Primary: mesio-distal diameter predominant. Squatted aspect

Permanent: cervico-incisal

Question 7

Primary vs Permanent crown:

Smaller crown

Answer 7

Primary

Question 8

Primary vs Permanent crown:

Incisors have develpomental grooves / mammelons?

Answer 8

Primary

Question 9

Primary vs Permanent crown:

Primary converge towards…?

Answer 9

occlusal of the facial and

lingual surfaces

Question 10

Primary vs Permanent crown:

narrower occlusal face?

Answer 10

primary

Question 11

Primary versus permanent crown:

Less accentuated cervical line?

Answer 11

Permanent

Question 12

Primary vs Permanent crown:

Constricted at the cervix?

Answer 12

primary

Question 13

Primary vs Permanent crown:

Thicker enamel and dentine layers?

Answer 13

Permanent

Question 14

Primary vs Permanent crown:

Primary enamel - rods in the cerival area are directed _____

Answer 14

occlusally

Question 15

Primary vs Permanent crown:

Primary - enamel finishes where?

Answer 15

in a well defined border

Question 16

Primary vs Permanent crown:

Primary molars have a prominent _____ bulge

Answer 16

mesio-buccal

Question 17

Primary vs Permanent crown:

Primary contact surfaces?

Answer 17

broad and flat

Question 18

Primary vs Permanent crown:

Lighter whiter color?

Answer 18

primary

Question 19

Primary vs Permanent crown:

Physiological erosion?

Answer 19

primary

Question 20

Primary vs Permanent roots:

Primary roots ____ & ____ comapared with crown

Answer 20

longer and thinner

Question 21

Primary vs Permanent roots anterior teeth:

primary roots are narrower in ____ direction

Answer 21

mesio-distal

Question 22

Primary vs Permanent roots anterior teeth:

Primary apical curves ___

Answer 22

buccaly

Question 23

Primary vs Permanent roots anterior teeth:

permanent tooth bud located ____

Answer 23

lingually

Question 24

Primary vs Permanent roots molars:

Primary have a more _____ cifurcation

Answer 24

cervical (cinodontia)

Question 25

Primary vs Permanent roots molars: | less divergent roots?

Answer 25

permanent

Question 26

Primary vs Permanent roots molars: | primary narrower _____ than _____

Answer 26

mesiodistally than buccalingually

Question 27

Primary vs Permanent pulp: | larger pulp?

Answer 27

primary

Question 28

Primary vs Permanent pulp: | Pulp horns closer to the outer surface?

Answer 28

primary

Question 29

Primary vs Permanent pulp: | Great variation in size and location?

Answer 29

primary

Question 30

Primary vs Permanent pulp: | lower mesial pulp horn?

Answer 30

permanent

Question 31

Primary vs Permanent pulp: | shallow pulp chamber?

Answer 31

primary

Question 32

Primary vs Permanent pulp: | form of pulp follows the external anatomy?

Answer 32

primary

Question 33

Primary vs Permanent pulp: | Usually a pulp horn under each cusp?

Answer 33

primary

Question 34

Primary vs Permanent pulp: Pulp chamber on the mandibular molars is bigger than the one in maxillary molars?

Answer 34

primary

Question 35

Primary vs Permanent pulp: | Anterior teeth have no clear separation between pulp chamber and root canal?

Answer 35

primary

Question 36

Primary vs Permanent physical properties: | hardness? (2)

Answer 36

smaller hardness of enamel and dentin

Question 37

Primary vs Permanent physical properties: | enamel permeability? why? (4)

Answer 37

higher permeability - Less time of formation. - Less mineralization. - Less thickness.

Question 38

Primary vs Permanent physical properties: caries progression?

Answer 38

- bigger and faster progress | - enables a better absorption of the fluor

Question 39

Primary vs Permanent physical properties: | radiopacity?

Answer 39

permanent: 92% minearl salts primary: 86-88%

Question 40

Primary vs Permanent physical properties: softness?

Answer 40

softer

Question 41

Primary vs Permanent physical properties: color?

Answer 41

lighter

Question 42

Primary vs Permanent histological properties: | enamel shape? (2)

Answer 42

prisms - have similar microscopical properties as permanent dentition - never get to external surface because crown has a thin layer of aprismatic enamel

Question 43

Primary vs Permanent histological properties: | aprismatic enamel?

Answer 43

-in primary dentition is all over the crown

Question 44

Primary vs Permanent histological properties: | apsrimatic enamel acid etching time?

Answer 44

longer time needed

Question 45

Primary vs Permanent histological properties: | Neonatal line?

Answer 45

may be seen - indicates separation between enamel formed before birth and after - LESS mineralized

Question 46

Primary vs Permanent histological properties: | Retzius lines?

Answer 46

- thin lines that mark position of different layers of enamel. - SCARCE in primary dentition

Question 47

Primary vs Permanent histological properties: | molar fossas?

Answer 47

We may find microdefects in the molar fossas. They | are imperceptible

Question 48

Primary vs Permanent histological properties: | dentin tubules?

Answer 48

less dense

Question 49

Primary vs Permanent histological properties: tubules?

Answer 49

- Less density of dentin tubules | - may see big tubules full of collagen type I & II INSTEAD of odontoblasts

Question 50

Primary vs Permanent histological properties: | interblobular spaces?

Answer 50

not many spaces

Question 51

Primary vs Permanent histological properties: | multiradial teeth?

Answer 51

may find incomplete fissures or cracks in the furcation area

Question 52

Primary vs Permanent histological properties: pulp? (3)

Answer 52

• Less histological development because their time of maturation is shorter. • Frequent anastomosis or unions between arteries and veins. • There are more nervous terminations in the crown than in the root.

Question 53

Primary vs Permanent histological properties: cement?

Answer 53

- May be celular or acelular cement | - predominance of acelular cement on upper 2 thirds of root

Question 54

Primary vs Permanent histological properties: | cement location?

Answer 54

- only present on the outer surface of the | root, it does not go inside the apex foramen

Question 55

Primary vs Permanent histological properties: | cement CEJ?

Answer 55

- enamel and the cement are always in contact, and | sometimes the cement overlaps the enamel