chapter 49: Matrix systems for restorative dentistry

Question 1

incorporated into the restorative procedure to create a temporary interproximal wall for the placement of amalgam, composite resin, and intermediate restorative materials

Answer 1

matrix system

Question 2

plural for matrix

Answer 2

matrices

Question 3

Two types of systems are routinely used for class II restorative procedure:

Answer 3

universal matrix

retainerless matrix

Question 4

also referred to as the Tofflemire retainer, is a mechanical device that holds the matrix band snugly in position.

designed for the placement of class II amalgam restorations and intermediate restorations

Answer 4

universal retainer

Question 5

The two designs of the matrix band are the

Answer 5

universal band and the extension band

Question 6

is selected for the class II preparation when the proximal “box” of the tooth preparation is at a minimum depth and width and the CUSPS are INTACT

Answer 6

universal band

Question 7

selected for a class II preparation with a more extensive preparation that requires gingival extensions to compensate for the loss of a cusp

Answer 7

extension band

Question 8

• The smaller circumference of the band is the gingival edge and is always positioned toward the ____.
• The larger circumference of the band is the occlusal edge and is always positioned on the tooth facing the _____ part of the tooth.

Answer 8

gingiva

occlusal

Question 9

Posterior composite restorations require a different type of matrix system than is used with the universal band and retainer.

t or f

Answer 9

true

Question 10

inserted into the lingual embrasure to hold the matrix band firmly against the gingival margin of the preparation

Answer 10

wedge

Question 11

The added pressure from a _____ pushes the matrix band against the proximal surface of the tooth, creating the contour of the finished restoration to match that of the natural tooth structure it replaces.

Answer 11

wedge

Question 12

The most commonly used type of wedge :

Answer 12

triangular or round wooden wedge

Question 13

The instrument used for inserting the wedge

Answer 13

110 (Howe) pliers.

Question 14

The key criterion to consider when placing a wedge is to create a seamless transition where the ____and the _____meet

Answer 14

tooth

restoration

Question 15

Improper wedge and band placement can result in :

Answer 15

overhang or in

cupping of the final material

Question 16

If a restoration is not contoured properly, it can result in an ____;

if the restoration is indented because of improper contouring, it can result in _____.

Answer 16

overhang

cupping

Question 17

type of matrix system used with anterior composite resin or glass ionomer materials

Answer 17

clear plastic matrix

Question 18

also referred to as the
celluloid strip or
Mylar strip, is used for a class III or IV restoration when the proximal wall of an anterior tooth is prepared

Answer 18

clear plastic matrix

Question 19

This system has no retainer to hold the band in place

Answer 19

automatrix system

Question 20

two types of matrix systems designed to provide the correct width and depth needed for proper restoration of PRIMARY molars.

Answer 20

tband

spot welded band

Question 21

is made from either stainless steel or copper and is in the shape of a T

Answer 21

tband

Question 22

form-fitted around the tooth with the use of #110 pliers. The band is then removed and placed in the smaller form of a welder that fuses the metal to make a custom band.

Answer 22

spot welded band