Linings and bases

Question 1

what do linings and bases protect the pulp from?

Answer 1

an overlying restorative material

Question 2

phosphoric acid based cements are composed of a powder containing what?

Answer 2

zinc oxide and other metallic oxides

Question 3

phosphoric acid based cements are composed of a liquid containing what?

Answer 3

aqueous phosphoric acid

Question 4

is the setting reaction of phosphoric acid based cements endo or exothermic?

Answer 4

exothermic

Question 5

how do you delay the set and increase the working time of phosphoric acid cement?

Answer 5

introduce the powder incrementally into the liquid

Question 6

why is phosphoric acid based cements highly irritating to the pulp?

Answer 6

low pH
low molecular weight so can penetrate deep into tubules

Question 7

positives of using phosphoric acid based cements 3

Answer 7

thermal and electrical insulator
strength to withstand condensation
radiopaque

Question 8

silicophosphate cements contain a liquid of aqueous phosphoric acid and buffers. what does the powder contain?

Answer 8

zinc oxide and aluminosilicate glass

Question 9

advantages of silicophosphate cements 3

Answer 9

great strength
less solubility
leach fluoride

Question 10

copper cements contain a liquid of aqueous phosphoric acid and buffers. what does the powder contain?

Answer 10

zinc oxide and black copper oxide

Question 11

zinc oxide eugenol cements are composed of a liquid containing what?

Answer 11

eugenol plus olive oil to control viscosity

Question 12

zinc oxide eugenol cements are composed of a powder containing what?

Answer 12

zinc oxide
hydrogenated resin/polystyrene for reinforcement

Question 13

positives of using zinc oxide eugenol cements

Answer 13

obtundant affect - soothing
bactericidal - zinc
thermal and electrical insulator
resin reinforcements can withstand condensation

Question 14

when should you not use zinc oxide eugenol cements?

Answer 14

not compatible with resin composites

Question 15

what are the two types of calcium hydroxide cement?

Answer 15

chemical activated
VLC - visible light cured activated

Question 16

chemical activated calcium hydroxide cement consists of a 2 pastes containing what?

Answer 16

paste 1: glycol salicylate
paste 2: zinc oxide with calcium hydroxide

Question 17

what is the setting reaction for calcium hydroxide cements?

Answer 17

VLC activated polymerisation of methacrylate monomer
monomer mixed with hydroxyethylmethacrylate

Question 18

what increases the rate of set of calcium hydroxide cements?

Answer 18

moisture

Question 19

visible light cured materials are endo or exothermic?

Answer 19

exothermic

Question 20

positives of using calcium hydroxide cements

Answer 20

high pH so beneficial irritancy and bactericidal
thermal and electrical insulators
good restorative material compatibility

Question 21

negatives of using calcium hydroxide cements

Answer 21

insufficient strength to withstand amalgam condensation/packing
not adhesive so no coronal seal

Question 22

polycarboxylates consist of a powder and liquid containing what?

Answer 22

powder - zinc oxide (or freeze dried)
liquid - aqueous solution of polyacrylic acid

Question 23

polycarboxylates have a strong bond to ?, weak bond to ? and non existant bond to ?

Answer 23

gold
stainless steel
porcelain

Question 24

polycarboxylates are mildly irritant. why?

Answer 24

acidic but have a high molecular weight reducing penetration

Question 25

positives of polycarboxylates

Answer 25

fluoride renders them bacteriostatic thermal and electrical insulator strength for amalgam condensation good restorative material combatibility adhesive to coronal seal

Question 26

what does RMGIC stand for?

Answer 26

resin modified glass ionomer cement

Question 27

positives of glass ionomers

Answer 27

bacteriostatic due to fluoride release thermal and electrical insulator strength to withstand restoration placement adhesive good restorative materials compatibility

Question 28

what is composite bulk fill

Answer 28

flowable composite with delayed/reduced shrinkage allows you to fill cavity in 4mm increments rather than 2mm like standard composite

Question 29

what does bulk dentine replacement biodentine consist of?

Answer 29

tricalcium silicate calcium carbonate zirconium oxide water super plasticising agent

Question 30

what does biodentine claim to do?

Answer 30

foster formation of reparative dentine