Lec 10 - Class 2 Flashcards Preview

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Flashcards in Lec 10 - Class 2 Deck (42):
1

class 2 challenge of achieving tight contacts solution

prewedge wooden or ring

2

class 2 challenge of achieving ideal proximal wall contours solution

using sectional matrices

3

class 2 challenge of achieving intimate gingival marginal seal

good wedging, use of flowable liners

4

when there are only interproximal caries in a class 2 we use this prep

class 2 slot

5

this type of class 2 is used when mesial and distal interproximals are carious as well as occlusal

MOD

6

modern composite systems are formulated with variations from the blank molecule for the last 50 years

bisGMA

7

when resin is exposed to light, there is a blank of the molecules

reorganizations

8

volumetric contraction (gelation, hardening, polymerization) of modern composite

2.6-7.1%

9

viscous plastic phase and material is able to flow

pre gel

10

viscous, flow cannot keep up with contraction phase

gel point

11

phase that is rigid elastic when contraction is obstructed stress occurs

post gel phase

12

this happens during post gel phase if bond strength is lower than stress

gap formation

13

this happens during post gel phase if bond strength is higher than the stress

deformation

14

invisible contraction leads to blank

stress

15

stress is usually this much

4-7 MPa

16

problems of contraction in posterior teeth include blank of the resin at the margins, formation of blank forces at the margins, blank in the enamel, and blank of the cusps

separation, tension, fractures, deformation

17

each resin needs a minimum amount of blank to obtain clinically acceptable results

energy

18

energy is measured in blank

joules

19

optimal energy to polymerize a resin

16 joules (40 seconds with curing light)

20

joules formula

watts x time

21

if you double the watts cant you just cut the time polymerizing time in half?

no because it takes time for energy to be absorbed

22

there are blank and blank polymerizing resins

fast, slow

23

blank is formed when the resin cannot adequately contract due to the bond between the resin and the walls

stress

24

during polymerization, only the blank surfaces can act as stress relievers during the plastic deformation of the resin

free

25

fewer free surfaces results in blank

more stress

26

ratio of bonded to unbonded surfaces

C factor

27

c factor of class 3 MF in anterior teeth

4/2=2

28

c factor of class 3 MFL in anterior teeth

3/3=1

29

c factor of class 4

2/4=.5 (lower stress)

30

c factor of class 5 veneer

1/5=5=.2

31

higher stresses are caused by a higher blank

c factor

32

these classes have the highest stress

class 1, class 5

33

class 1 / class 5 c factor

5/1=5

34

these classes have the lowest stress

3,4

35

halogen lights tend to have blank power and these are like the ones we use in b28

lower

36

50-400 J

low intensity

37

Joules =

mW/cm^2

38

400-800 J

medium intensity

39

1000 J +

high intensity

40

two theories to reduce stress generation during polymerization

control amount of resin being polymerized, control the amount of energy given to the resin

41

a way to decrease stress is to apply blank before blank

flowable composite, resin composite

42

a way to decrease stress is to apply final layers in blank orientation

oblique