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1. Matrix Systems for Restorative Dentistry Chapter 49
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
2. Chapter 49 Lesson 49.1 Copyright 2009, 2006 by Saunders, an
imprint of Elsevier Inc. All rights reserved.
3. Learning Objectives
Pronounce, define, and spell the Key Terms.
Describe the use of matrix systems in class II, III, and IV
restorations.
Describe the type of matrices used for posterior
restorations.
Describe the purpose and use of a wedge.
Discuss alternative methods of matrix systems used in
restorative dentistry.
Assemble a universal retainer and matrix band.
(Contd)
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
4. Learning Objectives
(Contd)
Place and remove a matrix band and wedge for a class II
restoration.
Place and remove a matrix band and wedge for a class III
restoration.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
5. Introduction
A matrix system provides a temporary wall for the restoration
process in class II, III and IV preparations.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
6. Posterior Matrix System
Universal retainer
Also referred to as Tofflemire retainer
Holds the matrix band in position
Positioned most commonly from the buccal surface of the tooth
being restored
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
7. Components of Universal Retainer Copyright 2009, 2006 by
Saunders, an imprint of Elsevier Inc. All rights reserved.
8. Matrix Bands
Thin, flexible stainless steel
Common designs
Universal
Extension
Guidelines for placement
Larger circumference: occlusal edge
Smaller circumference: gingival edge
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
9. Fig. 49-2 Most commonly used posterior matrix bands.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
10. Wedges
Positioned into the lingual embrasure of a class II preparation
after band placement
Positions the matrix band firmly against the gingival margin of
the preparation
Various sizes
Triangular/round
Wood/plastic
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
11. Fig. 49-5 Assortment of precontoured wedges. Copyright
2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights
reserved.
12. Anterior Matrix Systems
Plastic matrix
Also referred to as:
Celluloid matrix
Mylar strip
Used in Class III and IV restorations
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
13. Fig. 49-7 A clear matrix system. (Courtesy of Premier
Dental Products.) Copyright 2009, 2006 by Saunders, an imprint of
Elsevier Inc. All rights reserved.
14. Using an Anterior Matrix
Placed interproximally before the etching and bonding of a
tooth.
After the placement of composite material, a matrix is pulled
tightly around the tooth to help reconstruct its natural
contour.
A clear plastic matrix allows curing light to penetrate the
material and complete the curing process.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
15. Automatrix System
The automatrix system is an alternative to a universal
retainer.
No retainer is used to hold the band in place.
Preformed bands available in assorted sizes in both metal and
plastic.
Each band has a coil-like auto-lock loop.
A tightening wrench is inserted into the coil and turned
clockwise to tighten the band.
When the band is to be removed, a tightening wrench is inserted
into the coil and turned counterclockwise to loosen the band.
Removing pliers are used to cut the band.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
16. Fig. 49-9 Automatrix system. (Courtesy of Dentsply Caulk.)
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
17. Sectional Matrices
A thin, polished palodent-type band and tension ring produce
tight anatomic contact for composite resin materials in class II
restorations.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
18. Fig. 49-10 Sectional matrices. (Courtesy of Garrison Dental
Solutions.) Copyright 2009, 2006 by Saunders, an imprint of
Elsevier Inc. All rights reserved.
19. Matrix Systems for Primary Teeth
T-band
When formed, the top portion of the T allows the straight
portion to adjust and fit the circumference of the primary
molar.
Spot-welded band
Form-fitted band placed around a prepared tooth; removed and
placed in a smaller form of a welder, fusing the metal together to
make a custom band.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
20. Fig. 49-11 Copper T-band used for primary molars. Copyright
2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights
reserved.
21. Preparing the T-Band Matrix
The wings of the T-band are bent to form a U-shaped
trough.
The free end of the band is slipped loosely through the U
formation.
The wings are closed, and the free end is pulled to make a
small circle of the band.
Holding the free end toward the facial surface, place the band
on the tooth to be prepared.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.
22. Fig. 49-12 Spot welder used for primary molars. (Courtesy
of Unitek, Monrovia, Calif.) Copyright 2009, 2006 by Saunders, an
imprint of Elsevier Inc. All rights reserved.
23. Preparing a Spot-Welded Matrix Band
Measure to 1 inch of stainless-steel matrix material.
Fit the matrix band around the prepared tooth.
Adapt the band, making sure that the ends of the matrix
material are at the facial surface for the sake of visibility and
control.
Using Howe pliers, hold the ends tightly and remove the band in
an occlusal direction.
Place the band in the spot welder.
Spot-weld the matrix at three positions.
Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All
rights reserved.