Cementation Techniques

Question 1

True or False: Long term failure mechanism is unknown for single Zirconia crowns.

Answer 1

True

Question 2

Ziconia is a _____ not a _____.

Answer 2

ceramic

metal

Question 3

Why is there concern about Zirconia transforming over time and creating flaws that lead to failures?

Answer 3

it is metastable….low temperature degradation

Question 4

During stress corrosion, where does the stress occur?

Answer 4

on the underside of the crown

Question 5

Silanes put a ______ coating on glass particles.

Answer 5

hydrophobic

Question 6

Silica-based ceramics should be bonded with _____ cements to improve strength.

Answer 6

resin

Question 7

Non-silica based ceramics are ______ to bond.

Answer 7

difficult

Question 8

Non-silica based ceramics are strong enough to use _____ cements.

Answer 8

conventional

Question 9

What are the two broad categories of cements/luting agents?

Answer 9

1. Water-based

2. Resin-based

Question 10

What are the three water-based cements?

Answer 10

1. zinc phosphate
2. polycarboxylate
3. glass ionomers

Question 11

What is polycarboxylate a combination of?

Answer 11

ZO fillers + liquid of Glass Ionomer

its a combo of the other two water-based cements

Question 12

Why is Zinc Oxide tedious?

Answer 12

you must mix it (and it heats up, so you need cooled glass slab)

Question 13

Glass ionomers have a stable interface and release fluoride, but they are fairly ______.

Answer 13

soluble

Question 14

True or False: Resin Ionomers are more soluble than GI.

Answer 14

False, less soluble

Question 15

Composites and Compomers are _____-based cements.

Answer 15

resin

Question 16

What type of connections (2) exist between the tooth and crown and is filled by cement?

Answer 16

mechanical (mostly) and chemical

Question 17

The key to good cements include: _____film thickness, and _____ working time.

Answer 17

low

long

Question 18

Do we want a long or short setting time?

Answer 18

short

Question 19

Cement should have a ______ compressive strength and an elastic modulus that is similar to _____.

Answer 19

high

dentin

Question 20

Ideal cement has ______ solubility and _____ microleakage.

Answer 20

very low-none

very low-none

Question 21

Which type of cement should you use for metal or metal-ceramic crowns?

Answer 21

water based (ZO, resin modified GI)

Question 22

Which type of cement should you use for all-ceramic that are silica based?

Answer 22

resin cements

Question 23

Which type of cement should you use for all-ceramic crowns that are zirconia based?

Answer 23

water based or resin based

zirconia doesn’t need extra reinforcement

Question 24

True or False: For stronger ceramics, it is common to use resin based cements because the ceramic doesn’t need reinforcement from stronger bonding agents.

Answer 24

False: water-based cements can be used for stronger ceramics (zirconia)

Question 25

True or False: Adhesive Resins have a higher compressive strength.

Answer 25

True

Question 26

Dentin is etched with ______% phosphoric acid or self-etch adhesive.

Answer 26

35

Question 27

Which step is being removed from many resin systems because it can cause post op sensitivity?

Answer 27

etch

Question 28

Why does the etching step cause sensitivity?

Answer 28

it removes smear plugs and demineralizes dentin, which exposes tubules

Question 29

Self-etching adhesives will etch dentin during the ______ _______. This minimizes chances of sensitivity by may form a weaker bond.

Answer 29

adhesive application (good interface makes this possible)

Question 30

What kind of acid etchant is used for silica based ceramics?

Answer 30

hydrofluoric acid (5.5-5.9 HF)

Question 31

True or False: Zirconia based ceramics cannot be etched with hydrofluoric acid.

Answer 31

true

Question 32

After etching silica based ceramics, what is the next application step?

Answer 32

apply silane coupling agent

Question 33

The reaction of silane coupling with ceramic surface is known as _____.

Answer 33

condensation

Question 34

What is the purpose of using a silane coupling agent?

Answer 34

the long carbon chains and hydroxide groups are hydrophobic and the hydrogen atoms must be removed so that the oxygen can chemically attach to silane

Question 35

True or False: Zirconia is cemented similarly to metal but the inner surface is rough.

Answer 35

False: zirconia is cemented similar to metal BUT the inner surface is NOT rough

Question 36

What are the two conventional methods for cementation of metal to tooth?

Answer 36

1. Mechanical Lock | 2. Chelation (ionic bonds)

Question 37

What is the functional group in Glass Ionomer and RMGI?

Answer 37

carboxylic acid

Question 38

True or False: Conditioners clear the smear layer and demineralize tooth structure.

Answer 38

False: they only clear the smear layer...no demin

Question 39

Rely X is commonly used to cement Zirconia to tooth structure. What is Rely X Luting Cement?

Answer 39

an RMGI luting cement

Question 40

What are two characteristics of Phosphate Ester Based Cements when applied to Zirconia?

Answer 40

1. Mechanical Bonding is minimal 2. Stronger Ionic Bonding than carboxylic acid (RMGI) * example: Rely X Unicem*