Question 1

Which statement is incorrect concerning placement of the matrix retainer and band?

Accepted Answer

A)  The diagonal slotted surface of the retainer is always toward the gingiva.
B)  The handle of the retainer extends out from the oral cavity at the corners of the lips.
C)  The seated band extends two to three mm above the occlusal surface of the tooth.
D)  The retainer is positioned from the buccal side of the tooth.

Question 2

Which of the statements is incorrect about a spot-welded band?

Accepted Answer

A)  The spot-welded band is a custom fitted band.
B)  The spot-welded band measures 3/4 to 1 inch of copper material.
C)  A #110 pliers is used to adapt the band to ensure the ends of the matrix are at the facial surface.
D)  The matrix is welded at three positions before being placed on the tooth.

Question 3

If a cusp is lost during preparation,which matrix band would provide the best support while restoring?

Accepted Answer

A)  Universal
B)  Copper
C)  Palodent
D)  Extension D

Question 4

Which matrix system that is used with posterior composite restorations?

Accepted Answer

A)  AutoMatrix
B)  Tofflemire
C)  T-band
D)  Palodent

Question 5

Which of the following is the instrument of choice when positioning a wooden wedge?

Accepted Answer

A)  Amalgam carrier
B)  Mouth mirror
C)  Howe pliers
D)  Cowhorn explorer

Question 6

What is one advantage of an AutoMatrix over a universal matrix?

Accepted Answer

A)  Available in various sizes
B)  No retainer to hold the band in place
C)  Does not require use of a wedge
D)  Requires no tightening of the band

Question 7

Why is a matrix band contoured prior to placing the restorative material?

Accepted Answer

A)  Ensure that the band will fit the tooth being restored.
B)  Curl the band to make it easier to fit the tooth.
C)  Ensure that the final restoration will have proper contact with the adjacent tooth.
D)  Ensure that there is no cupping of the final restoration. C

Question 8

Where is the wedge positioned when placing a posterior restoration?

Accepted Answer

A)  Facial
B)  Lingual
C)  Buccal
D)  Labial

Question 9

What is the material of choice for a universal matrix band?

Accepted Answer

A)  Thin, flexible stainless steel
B)  Thick, flexible stainless steel
C)  Celluloid
D)  Thin, flexible copper

Question 10

Which matrix system used for class II posterior restorations is the most common?

Accepted Answer

A)  Tofflemire retainer and universal band
B)  Clear Mylar matrix
C)  T-band matrix
D)  AutoMatrix system A

Question 11

The ______ is used to decrease the size of the matrix band loop after the band has been placed on the tooth.

Accepted Answer

A)  spindle
B)  outer knob
C)  inner knob
D)  guide channel

Question 12

If a patient is having a class V restoration on the lower left first molar,which type of matrix system would be used?

Accepted Answer

A)  Tofflemire matrix with a wedge
B)  AutoMatrix system
C)  Mylar system
D)  None of the above

Question 13

What is the component of the universal matrix retainer that holds the matrix band securely in the device called?

Accepted Answer

A)  Spindle
B)  Guide channel
C)  Inner knob
D)  Diagonal slot

Question 14

The larger side of the universal matrix band loop is always directed toward which part of the tooth?

Accepted Answer

A)  Gingival one third
B)  Incisal one third
C)  Occlusal one third
D)  Buccal one third

Question 15

Once the AutoMatrix band is positioned on the tooth,how is the band tightened?

Accepted Answer

A)  A wrench turns the coil counterclockwise to tighten the band.
B)  Use fingers to turn the coil until it is snug.
C)  A wrench turns the coil clockwise to tighten the band.
D)  It is wedged to form the contour.

Question 16

Which statement is correct regarding posterior metal matrix bands?

Accepted Answer

A)  The smaller circumference of the band is placed toward the occlusal.
B)  The smaller circumference is placed toward the gingiva.
C)  The larger circumference of the band is the gingiva.
D)  Both ends of the band need to be contoured.

Question 17

Which statement is correct concerning wedges?

Accepted Answer

A)  A wedge is used to apply pressure to the apical and gingival walls of the preparation.
B)  The wedge presses the band against the tooth, causing a slight separation of the teeth.
C)  The most commonly used type of wedge is the rounded plastic form.
D)  Both a and b are correct statements.

Question 18

What is the component of the universal matrix retainer that is always positioned in the mouth facing the gingiva called?

Accepted Answer

A)  Spindle
B)  Outer guide slot
C)  Inner knob
D)  Diagonal slot

Question 19

For there to be a solid closure of margins on a posterior composite restoration,where should the prongs of the tension ring for the Palodent system be placed?

Accepted Answer

A)  Distal to the band and wedge
B)  Between the band and wedge
C)  Mesial to the band and wedge
D)  Buccal to the band and wedge

Question 20

Why should stainless steel matrix bands not be used with composite resin materials?

Accepted Answer

A)  Resins can be scratched by the stainless steel.
B)  Stainless steel can interfere with the setting of the resins.
C)  Stainless steel can stain the color of the resin.
D)  Both a and b are correct.

Exam 49: Matrix Systems for Restorative Dentistry

Which statement is incorrect concerning placement of the matrix retainer and band?

Correct AnswerverifiedShow Answer

Which of the statements is incorrect about a spot-welded band?

Correct AnswerverifiedShow Answer

If a cusp is lost during preparation,which matrix band would provide the best support while restoring?

Correct AnswerverifiedD

Which matrix system that is used with posterior composite restorations?

Correct AnswerverifiedShow Answer

Which of the following is the instrument of choice when positioning a wooden wedge?

Correct AnswerverifiedShow Answer

What is one advantage of an AutoMatrix over a universal matrix?

Correct AnswerverifiedShow Answer

Why is a matrix band contoured prior to placing the restorative material?

Correct AnswerverifiedC

Where is the wedge positioned when placing a posterior restoration?

Correct AnswerverifiedShow Answer

What is the material of choice for a universal matrix band?

Correct AnswerverifiedShow Answer

Which matrix system used for class II posterior restorations is the most common?

Correct AnswerverifiedA

The ______ is used to decrease the size of the matrix band loop after the band has been placed on the tooth.

Correct AnswerverifiedShow Answer

If a patient is having a class V restoration on the lower left first molar,which type of matrix system would be used?

Correct AnswerverifiedShow Answer

What is the component of the universal matrix retainer that holds the matrix band securely in the device called?

Correct AnswerverifiedShow Answer

The larger side of the universal matrix band loop is always directed toward which part of the tooth?

Correct AnswerverifiedShow Answer

Once the AutoMatrix band is positioned on the tooth,how is the band tightened?

Correct AnswerverifiedShow Answer

Which statement is correct regarding posterior metal matrix bands?

Correct AnswerverifiedShow Answer

Which statement is correct concerning wedges?

Correct AnswerverifiedShow Answer

What is the component of the universal matrix retainer that is always positioned in the mouth facing the gingiva called?

Correct AnswerverifiedShow Answer

For there to be a solid closure of margins on a posterior composite restoration,where should the prongs of the tension ring for the Palodent system be placed?

Correct AnswerverifiedShow Answer

Why should stainless steel matrix bands not be used with composite resin materials?

Correct AnswerverifiedShow Answer

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