Deck 49: Matrix Systems for Restorative Dentistry

Question 1

The Tofflemire retainer that has been designed with a slight bend in the body to accommodate positioning from the lingual surface is known by what name?

A)AutoMatrix
B)Palodent-type matrix band
C)Contra-angle
D)Spot-welded band

Answer 1

Contra-angle

Question 2

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

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.

Answer 2

Ensure that the final restoration will have proper contact with the adjacent tooth.

Question 3

To contour a metal matrix band for posterior teeth,place the band on a paper pad and rub the inner surface of the band with _____ until the ends begin to curl.

A)a ball-point pen
B)a burnisher or the end of a mirror handle
C)a pencil eraser
D)your finger

Answer 3

a burnisher or the end of a mirror handle

Question 4

Which type of matrix system is used for the primary molars?

A)T-band
B)AutoMatrix
C)Spot-welded band
D)Either a or c

Question 5

Where is the wedge positioned when placing a posterior restoration?

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

Question 6

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

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

Question 7

How would an anterior matrix band be contoured?

A)Mirror handle
B)Explorer
C)Scaler
D)Mandrel

Question 8

Where should the cervical margin of a matrix band lie?

A)One millimeter beyond the gingival floor
B)Three milliliters beyond the gingival floor
C)One millimeter above the gingival floor
D)At the level of the gingival floor

Question 9

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

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

Question 10

Which statement is correct regarding posterior metal matrix bands?

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 11

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

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

Question 12

Which statement is correct concerning wedges?

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 13

Mylar strips are used for class ___ restorations.

A)I
B)II
C)III
D)V

Question 14

The universal,or Tofflemire,retainer holds the matrix band snugly in position.It is most often positioned in which area?

A)Toward the anterior of the mouth
B)On the buccal surface of the tooth being restored
C)On the lingual surface of the tooth being restored
D)Toward the posterior of the mouth

Question 15

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

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 16

What is the purpose of a matrix system?

A)Retain and support the restoration.
B)Provide a temporary interproximal wall for the restorative material.
C)Create an external surface against which the restorative material is packed.
D)Both b and c are correct.

Question 17

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

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

Question 18

A matrix must be used to create a temporary wall for which of the following classifications of tooth restoration?

A)Classes I and V
B)Classes II and IV
C)Classes II and III
D)Both b and c

Question 19

Which matrix system is used for anterior composite resin or glass ionomer restorations?

A)AutoMatrix
B)Clear plastic matrix
C)Tofflemire
D)T-band

Question 20

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

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.

Question 21

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

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

Question 22

What is the component of a universal matrix retainer that serves to guide the direction of the matrix loop according to the quadrant that is being treated called?

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

Question 23

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

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 24

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

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 25

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

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

Question 26

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

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

Question 27

Which statement is correct concerning the purpose of the anterior matrix systems? (Select all that apply.)

A)The matrix protects the adjacent tooth during preparation.
B)The clear plastic allows the curing light to penetrate the material, completing the curing process.
C)The matrix protects the adjacent teeth from the materials.
D)The matrix helps in reconstructing the natural contour of the tooth.
E)The height of the band signifies the height of the marginal ridge.

Question 28

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

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

Question 29

What is the term for excess restorative material that extends beyond the cavity margin?

A)Overhang
B)Celluloid
C)Cupping
D)Diastema

Question 30

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

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

Question 31

What is the correct order of steps for preparing the T-band matrix?
1) Close the wings and pull the free end to make a small loop of the band.
2) Holding the free end of the band toward the facial,place the band loop on the tooth.
3) Bend the wings of the T-band to form a U-shape.
4) Slip the free end of the band through the U formation.

A)1, 2, 3, 4
B)2, 3, 4, 1
C)3, 4, 1, 2
D)1, 3, 4, 2

Question 32

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?

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 33

Which matrix system that is used with posterior composite restorations?

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

Question 34

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

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