Matrix Systems

Copyright 2003, Elsevier Science (USA). All rights reserved.

Matrix Systems for Restorative Dentistry Matrix Systems for

Restorative Dentistry

Chapter 49Chapter 49

Copyright 2003, Elsevier Science (USA).

All rights reserved. No part of this product may be reproduced or transmitted in any form or by any means, electronic or mechanical, including input into or storage in any information system, without permission in writing from the publisher.

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Produced in the United States of America

ISBN 0-7216-9770-4


IntroductionIntroduction A matrix system provides and takes the

place of the proximal tooth surface that was removed to restore the proximal contours and contact to their normal shape and function.

A matrix system provides and takes the place of the proximal tooth surface that was removed to restore the proximal contours and contact to their normal shape and function.


Posterior Matrix SystemPosterior Matrix System

Universal retainer• Also referred to as the Tofflemire

retainer. This device holds the matrix band in position. The retainer is positioned most commonly from the buccal surface of the tooth being restored.

Universal retainer• Also referred to as the Tofflemire

retainer. This device holds the matrix band in position. The retainer is positioned most commonly from the buccal surface of the tooth being restored.


Components of a Universal Retainer Components of a Universal Retainer


Posterior Matrix System cont’dPosterior Matrix System cont’d Matrix bands

• Matrix bands are made of flexible stainless steel and are available in premolar, molar, and universal sizes and thicknesses.

• The larger circumference of the band is the occlusal edge and is always placed toward the occlusal surface.

• The smaller circumference of the band is the gingival edge and it is always placed toward the gingiva.

Matrix bands• Matrix bands are made of flexible

stainless steel and are available in premolar, molar, and universal sizes and thicknesses.

• The larger circumference of the band is the occlusal edge and is always placed toward the occlusal surface.

• The smaller circumference of the band is the gingival edge and it is always placed toward the gingiva.


Fig. 49-2 Types of matrix bands.Fig. 49-2 Types of matrix bands.


WedgesWedges

A wedge is either triangular or round and made of wood or plastic.

The wedge is inserted into the lingual embrasure to position the matrix band firmly against the gingival margin of the preparation.

A wedge is either triangular or round and made of wood or plastic.

The wedge is inserted into the lingual embrasure to position the matrix band firmly against the gingival margin of the preparation.


Fig. 49-6 A wedge correctly positioned. Fig. 49-6 A wedge correctly positioned.


Automatrix System Automatrix System The automatrix system is an alternative to a universal

retainer. There is no retainer used to hold the band in place. Bands are already formed into a circle and are

available in assorted sizes in both metal and plastic. Each band has a coil like autolock loop. A tightening wrench is inserted into the coil and

turned clockwise to tighten the band. When finished, the tightening wrench is inserted into

the coil and turned counterclockwise to loosen the band.

Removing pliers are used to cut the band.

The automatrix system is an alternative to a universal retainer.

There is no retainer used to hold the band in place. Bands are already formed into a circle and are

available in assorted sizes in both metal and plastic. Each band has a coil like autolock loop. A tightening wrench is inserted into the coil and

turned clockwise to tighten the band. When finished, the tightening wrench is inserted into

the coil and turned counterclockwise to loosen the band.

Removing pliers are used to cut the band.


Matrix Systems for Primary Teeth Matrix Systems for Primary Teeth The T-band is a T-shaped copper band. When formed, the top portion of the T

allows the straight portion to adjust and fit the circumference of the primary molar.

The T-band is a T-shaped copper band. When formed, the top portion of the T

allows the straight portion to adjust and fit the circumference of the primary molar.


Fig. 49-7 Example of copper T-band used for primary molars.Fig. 49-7 Example of copper T-band used for primary molars.


Preparing the T-Band Matrix 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.

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.


A spot-welded band is a form-fitted band placed around a prepared tooth, then removed and placed in a smaller form of a welder that fuses the metal together to make a custom band.

A spot-welded band is a form-fitted band placed around a prepared tooth, then removed and placed in a smaller form of a welder that fuses the metal together to make a custom band.

Additional Matrix Systems for Primary TeethAdditional Matrix Systems for Primary Teeth


Fig. 49-8 Spot-welded band.Fig. 49-8 Spot-welded band.


Preparing a Spot-Welded Matrix Band Preparing a Spot-Welded Matrix Band

Measure ¾ to 1 inch of stainless steel matrix material.

Fit the matrix materials around the prepared tooth.

Adapt the band, making sure the ends of the matrix material is at the facial surface for visibility and control.

Holding the ends tightly, remove the band in an occlusal direction.

Place the band in the spot welder. Spot-weld the matrix at three positions.

Measure ¾ to 1 inch of stainless steel matrix material.

Fit the matrix materials around the prepared tooth.

Adapt the band, making sure the ends of the matrix material is at the facial surface for visibility and control.

Holding the ends tightly, remove the band in an occlusal direction.

Place the band in the spot welder. Spot-weld the matrix at three positions.


Matrices for Composite Restorations Matrices for Composite Restorations

A plastic matrix, also referred to as a celluloid matrix or mylar strip, is used for class III and IV restorations in which the proximal wall of an anterior tooth is missing.

A plastic matrix, also referred to as a celluloid matrix or mylar strip, is used for class III and IV restorations in which the proximal wall of an anterior tooth is missing.


The Use of a Clear MatrixThe Use of a Clear Matrix

The matrix is placed interproximally before the etching and priming of a tooth. This protects adjacent teeth from these materials.

After placement of composite material, a matrix is pulled tightly around the tooth to help reconstruct its natural contour.

The clear plastic matrix allows the curing light to penetrate the material and complete the curing process.

The matrix is placed interproximally before the etching and priming of a tooth. This protects adjacent teeth from these materials.

After placement of composite material, a matrix is pulled tightly around the tooth to help reconstruct its natural contour.

The clear plastic matrix allows the curing light to penetrate the material and complete the curing process.


Sectional Matrices Sectional Matrices A thin polished palodent-type band

and a tension ring produce a tight anatomic contact for composite resin materials for class II restorations.

A thin polished palodent-type band and a tension ring produce a tight anatomic contact for composite resin materials for class II restorations.


Fig. 49-10 Sectional matrices.Fig. 49-10 Sectional matrices.

Matrix Systems

Documents

t band matrix

custom band

matrix materials

clear matrix

clear plastic matrix

types of matrix bands

polishedpalodent type

additional matrix systems