Chapter 5

Question 1

The most commonly used etchant/ conditioner for tooth bonding is

Answer 1

Phosphoric acid

ranges from 10-38%

Question 2

Etched surface of a permanent tooth should have a ____ appearance when dried

Answer 2

frosty

Question 3

Smear layer

Answer 3

when a cavity prep is cut, Layer of debris from cutting forms on the surface of the cut dentin and enamel

Question 4

3 things about smear layer

Answer 4

1. Composed of mostly tooth structure (hydroxyapatite and collagen) may also contain plaque, bacteria, saliva, and even blood.
2. sticks tenaciously to the dentin surface and plug the opening of dental tubules and can’t be washed off with an air and water syringe
3. interfere with the formation of the bond to dentin

Question 5

What is etching

Answer 5

on enamel, removes a small portion of the surface
- reduces the ends of the enamel rods, and created microscopic pored between adjacent rods
- creates a highly roughed surface with many tiny pores where resin can lock

Question 6

Acid that creates the best etching pattern

Answer 6

Phosphoric acid

Question 7

How does Etchant Come and how is it dispensed

Answer 7

Liquid - brush, small cotton pellet, small sponge

Gel- dispensed from a syringe, needle tip, or brush

Benefits of gel- they contain silica and they stay in place

Question 8

How long to etch enamel on permanent teeth

Answer 8

20-30 sec

Question 9

How long to etch enamel on highly mineralized

Answer 9

up to 60 due to being more resistant

Question 10

How long to etch enamel on primary teeth

Answer 10

60+ sec, due to enamel having a prism pattern that is not as well structured and is more resistant to deep resin tag formation

Question 11

When etching both enamel and dentin as in a coronal cavity preparation, what is the best way

Answer 11

Apply the acid to the enamel first for 10 seconds, and then to the dentin for 10 seconds. That way enamel will be etched for a total of 20 seconds and dentin only 10 seconds.

Question 12

Which etch or tooth conditioner is used when seating or repairing ceramic restorations?

Answer 12

Hydrofluoric acid

Question 13

When are posts placed within the roots of endodontically treated teeth to retain dental materials used to build up the teeth

Answer 13

When coronal tooth structure is inadequate for restorations with a crown

Question 14

Etch gel is typically a ___% of phosphoric acid

Answer 14

37

Question 15

What is it called when teeth have been over dried after etching

Answer 15

desiccation

Question 16

Desiccation Why can this contribute to postoperative sensitivity?

Answer 16

Traps air in the dentinal tubules, when the patient bites down, the restoration compresses the dentin, putting pressure on the air in the tubules.

Question 17

Contaminants on the surface of the tooth can greatly affect the longevity of the restoration and may include?

Answer 17

saliva, blood, food

Question 18

what to do if the enamel becomes contaminated

Answer 18

rinse and re-etch for 10-15 sec

Question 19

micro leakage

Answer 19

Leakage of fluid and bacteria caused by microscopic gaps that occur at the interface of the tooth and the restoration margins.

When would it occur?
When contaminants are not removed.

Question 20

3 modes of cure

Answer 20

1. Self- process- (chemical) chemical reactions occur when two chemicals are mixed together
2. Light cure- blue light
3. dual cure- self cure and light

Question 21

One primary reason for sensitivity (postoperative) is unsealed dentinal tubules. How do the unsealed dentinal tubules occur?

Answer 21

Phosphoric acid etching removes the smear layer and smear plugs in the tubules leaving open tubules. If they are not sealed during the bonding process, a number of things can influence the pressure on the fluid in the tubules and elicit a pain response.