Deck 49: Matrix Systems for Restorative Dentistry

Question 1

Mylar strips are used for class ___ restorations.

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

Answer 1

III

Question 2

Stainless steel matrices cannot be used for anterior composite resins because the:

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.

Answer 2

both a and b.

Question 3

Which of the following statements is true of posterior metal matrix bands?

A)The smaller circumference of the band is the occlusal edge.
B)The smaller circumference is placed toward the gingival edge.
C)The larger circumference of the band is the gingival edge.
D)The edge of the band is contoured in the proximal contact area.

Answer 3

The smaller circumference is placed toward the gingival edge.

Question 4

Which statement is true 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 true statements.

Question 5

The _____ is used as a matrix system for the primary molars.

A)T-band
B)automatrix
C)spot-welded band
D)either a or c

Question 6

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

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

Question 7

A(n) _____ Tofflemire retainer has been designed with a slight bend in the body to accommodate positioning from the lingual surface.

A)automatrix
B)Palodent-type matrix band
C)contra-angle
D)spot-welded band

Question 8

The universal,or Tofflemire,retainer holds the matrix band snugly in position and is most often positioned:

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 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

The purpose of contouring a matrix band is to:

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.

Question 11

Which statement is not true 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 12

If there is a loss of a cusp making the preparation deeper,a(n) _____ band may be selected.

A)universal
B)copper
C)Palodent
D)extension

Question 13

Which statement(s) is(are) true concerning the purpose of the anterior matrix systems?

A)The clear plastic allows the curing light to penetrate the material, completing the curing process.
B)The matrix protects the adjacent teeth from the materials.
C)The matrix helps in reconstructing the natural contour of the tooth.
D)All of the above are true statements.

Question 14

For posterior restorations,the wedge is positioned from the _____ side.

A)facial
B)lingual
C)buccal
D)labial

Question 15

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

Question 16

The material of choice for a posterior matrix band is::

A)thin, flexible stainless steel.
B)thick, rigid stainless steel.
C)celluloid.
D)thin, flexible copper.

Question 17

The _____ is used for anterior composite resin or glass ionomer restorations.

A)automatrix
B)clear plastic matrix
C)Tofflemire
D)T-band

Question 18

The most common matrix system used for class II posterior restorations is the:

A)Tofflemire retainer and matrix band.
B)clear plastic matrix.
C)T-band matrix.
D)automatrix system.

Question 19

The purpose of a matrix system is to:

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.

Question 20

When a posterior metal matrix band and retainer are placed,the seated matrix band should extend approximately _____ mm below the gingival margin of the preparation.

A)one
B)three
C)six
D)negative two (It should actually be above the margin of the gingival preparation.)

Question 21

Once the automatrix band is positioned on the tooth,a tightening wrench is inserted into the coil and turned:

A)counterclockwise to tighten the band.
B)until the coil is snug around the tooth.
C)clockwise to tighten the band.
D)to form the contour around the tooth.

Question 22

The component of the universal matrix retainer that is always positioned in the mouth facing the gingiva is the:

A)spindle.
B)outer guide slot.
C)inner knob.
D)diagonal slot.

Question 23

Which of the statements is not true of the spot-welded band?

A)The spot-welded band is a custom fitted band.
B)The spot-welded matrix band measures ¾" to 1" 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 24

If a patient is having a class V restoration on the lower left first molar,what 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 25

The larger side of the universal matrix band loop is always toward the____ third of the tooth.

A)gingival
B)incisal
C)occlusal
D)buccal

Question 26

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 27

The component of the universal matrix retainer that holds the matrix band securely in the device is the:

A)spindle.
B)guide channels.
C)inner knob.
D)diagonal slot.

Question 28

An advantage of the automatrix system over the universal retainer is the automatrix system:

A)is available in various sizes.
B)needs no retainer to hold the band in place.
C)does not require use of a wedge.
D)requires no tightening of the band.

Question 29

Excess restorative material that extends beyond the cavity margin is a/(n):

A)overhang.
B)celluloid.
C)cupping.
D)diastema.

Question 30

To create a solid closure of the cavity preparation for posterior composite restorations,the prongs of the tension ring for the Palodent systems are placed _____ the band and wedge.

A)distal to
B)between
C)mesial to
D)buccal to

Question 31

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 is the:

A)spindle.
B)outer guide slots.
C)inner knob.
D)diagonal slot.

Question 32

The system that is used with posterior composite restorations is the:

A)automatrix.
B)Tofflemire.
C)T-band.
D)Palodent.

Question 33

To contour an anterior matrix band,pull the matrix lengthwise over a rounded surface such as a(n):

A)mirror handle.
B)explorer.
C)scaler.
D)none of the above.

Question 34

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 channels