protecting the pulp

Question 1

Sources of chemical attack?

Answer 1

acrylic resin
acids in bonding agents
residual acid from acidogenic bacteria

Question 2

sources of thermal shock?

Answer 2

polymerisation exotherm of some restorative materials
light curing units
food and drinks
cavity prep

Question 3

galvanic shock?

Answer 3

restorations of dissimilar metals in close proximity

Question 4

What is the smear layer?

Answer 4

result of prep

occludes dentinal tubules with bacteria, collagen, hydroxyapitite

Question 5

Properties of calcium hydroxide?

Answer 5

high PH- initially irritant- reactionary dentine
high PH- bacteriocidal
thermal/ electrical insulator
radiopaque
compatible with restorative materials
Not adhesive- no coronal seal
insufficient strength for condensation

Question 6

Properties of zinc polycarboxylate cements

Poly F

Answer 6

high molecular weight reduces penetrations to tubules
contains fluoride + zinc- bacteriostatic
good strength for restoration placement
insulates
good compatibility

Question 7

properties of zinc oxide and euganol

Kalzinol, sedanol

Answer 7

slightly irritant- reactionary dentine
bacteriocidal- zinc
insulates
obtundant- euganol
not adhesive- no coronal seal
not compatible with resin composite

Question 8

Properties of zinc phosphate

Answer 8

rarely used due to highly irritant

Question 9

properties of glass polyalkenoates

baseline, vitrebond

Answer 9

mildy irriatant- reactionary dentine
bacteriostatic- fluoride
insulator
sufficient strength
coronal seal
good compatibility

Question 10

when to line?

Answer 10

when cavity extends more than 2mm

when cavities is within 2 mm of pulp

Question 11

where do you place linings?

Answer 11

pulp- axial wall and/or occlusal floor

Question 12

what effect may lining the base of a cavity have?

Answer 12

weaken overlying filling material

Question 13

When will a patient experience discomfort?

Answer 13

when caries reaches within 0.5mm of pulp

Question 14

when is an indirect pulp cap used?

Answer 14

when cavity extends to within 0.5mm of pulp

Question 15

what material is used for indirect pulp cap?

Answer 15

hard setting calcium hydroxide to the deepest part of the cavity
can be covered in resin modified GI

Question 16

when is a direct pulp cap used?

Answer 16

when pulp is exposed

Question 17

What materials are used for direct pulp caps?

Answer 17

calcium hydroxide- hard setting

mineral trioxide aggregate- MTA

Question 18

what it the criteria for direct pulp capping?

Answer 18

tooth is vital
no hx of pain
pulp must be pink and healthy with no excessive bleeding

Question 19

What is the technique for direct pulp capping?

Answer 19

dry tooth with cotton wool- NO AIR
apply material to exposure
resin modified GI may be applied on top
restore as normal

Question 20

When is step wise excavation used?

Answer 20

when trying to avoid exposing pulp

Question 21

what can be left in cavity re. step wise excavation?

Answer 21

stained soft dentine

Question 22

what must be clear re. step wise?

Answer 22

ADJ

Question 23

what is the technique used re. stepwise?

Answer 23

seal entire base of cavity where caries remains with calcium hydroxide
Dress with GI
Remove GI and lining 6-12 months later

Question 24

How should base of lining be after 6-12 months

Answer 24

still stained, but firm