**Retraction Cord

Question 1

True or False: When packing cord for a restoration, the cord needs to be placed around the entire tooth.

Answer 1

False

Question 2

How much healthy tooth structure should be exposed in the impression for the lab to fabricate a successful crown?

Answer 2

the prep line and 0.5-1mm of additional healthy tooth structure

Question 3

What is the smallest size of retraction cord?

Answer 3

000

Question 4

What type of retraction cord is preferred, and why?

Answer 4

braided cord is preferred over knitted because knitted can fray easier

Question 5

Who chooses the size of the retraction cord to be placed?

Answer 5

the operator

Question 6

What additive promotes contraction of the tissues?

Answer 6

astringent

Question 7

What additive constricts the blood flow by causing coagulation?

Answer 7

hemostatic

Question 8

True or False: Cord cannot be layered with multiple pieces.

Answer 8

False

Question 9

When placing two pieces of cord, what size should be packed first?

Answer 9

the smaller size

Question 10

How should cord be packed?
-clockwise
-counterclockwise

Answer 10

clockwise

Question 11

What area of the prep should you begin packing the cord?

Answer 11

at the proximal areas

Question 12

When the tissue is rebounding and the cord is difficult to place, what type of pressure should you use with the cord packing instrument to aid in easier packing?

Answer 12

Do not press harder; use firm but gentle pressure for a longer time period

Question 13

How long should the cord remain in place prior to removal?

Answer 13

5-6 minutes

Question 14

When removing the cord, should you keep the cord dry or moisten the cord?

Answer 14

moisten

Question 15

How long after the cord is removed will the tissue remain retracted?

Answer 15

30 seconds

Question 16

What is cordless retraction paste made out of?

Answer 16

diatomaceous clay and aluminum chloride

Question 17

Aside from placing a rubber dam, what is the most effective and most common method to achieve ginigval retraction?

Answer 17

packing cord

Question 18

What chemical has been added to impregnated cord that is no longer recommended to be used?

Answer 18

racemic epinephrine

Question 19

Does retraction cord shrink or expand when wet?

Answer 19

expand

Question 20

List some common chemical additives to retraction cord.

Answer 20

-racemic epinephrine(contraindicated)
-ferric sulfate
-aluminum potassium sulfate
-aluminum sulfate

Question 21

How long after the retraction cord has been removed can the chemical additives in the cord continue to have beneficial effect on the tissue?

Answer 21

20 minutes

Question 22

For a crown prep, what is the average length of cord needed to completely surround the entire tooth?

Answer 22

1-1.5 inches

Question 23

If retraction cord needs to be overlapped, what area is best indicated to place the second piece?

Answer 23

the proximal area

Question 24

Why is it commonly contraindicated to overlap cord around the buccal/facial or lingual margins of the tooth?

Answer 24

the gingiva here is tighter and thinner and can cause gapping that will distort the accuracy of the impression