Restorative Pediatric

Dentistry

Dr. Sami Malik Abdulhameed

B.D.S.; M.Sc. Certificate Ped. Dent

Matrix Systems for Pediatric

Restorative Dentistry

Introduction

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.

They hold the restorative material in thecavity, restore the tooth to original formand preserve the arch length andanatomic function.

The matrix band should be rigid enoughto allow adequate packing pressure,ensuing a well-condensed restorationfree from an excessive mercury.

Should also prevent extension of excessrestorative material beyond the bandinto the gingival tissue causing overhanging amalgam restoration.

Sunday, October 30, 2016 5

DIFFERENT MATRIX BANDS AND RETAINERS

Sunday, October 30, 2016 6

Sunday, October 30, 2016 7

1. Matrices for Class I cavity (compound cavity)

Double banded tofflemire

2. Matrices for Class II

Single banded tofflemire

Ivory matrix No. 1

Ivory matrix NO. 8

Black's matrices

Soldered band matrix

Anatomical matrix

Auto-matrix

S-shaped matrix band

T-shaped matrix band

3. Matrices for a cavity preparation for amalgam on distal of cuspid.

S shaped matrix

Tofflemire

Sunday, October 30, 2016 8

4. Matrices for Class III for tooth coloured restorations

Transparent celluloid strips

5. Matrices for Class IV for tooth coloured restorations

Celluloid strips

Aluminum foil (non-light cure)

Anatomic matrix .

Modified S shaped band of copper, tin, aluminum

foil (non-light cure)

Sunday, October 30, 2016 9

Matrix band for primary and permanent Class

II composite & Amalgam restorations

Choosing the best matrix system for the

procedure and the patient can enhance clinical

success

• The amalgam restoration in the Class II cavity

needs the use of a matrix retainer. The matrix

should be rigid enough to allow adequate

packing pressure, ensuring a well-condensed

restoration free from an excess of residual

mercury.

• When restoring Class II with amalgam or adhesive

restorations in children, teenagers, and adults, the

goal is to provide 1) tight contacts, 2) good contours,

and 3) proper anatomy. There are many types of

matrices on the market, however, in restoring

thousands of restorations in children and teenagers,

we have found that fender mate ,segmental metal

and auto matrices provide for all three goals.

examples of available matrices.

Types of Matricesw Tofflemire ( Universal retainer )

• does not fit contour of primary tooth well

• difficult to fit multiple matrices

* Spot welded requires a spot welder chairside

*T-band

w *Automatrix – Metal & Transperent costly

* Sectional

* Fender Mate

w allows for multiple matrix placement

Posterior 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.

Components of a Universal Retainer

Sunday, October 30, 2016 16

Posterior 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.

Fig. 49-2 Types of matrix bands.

Copper T-band used for primary molars.

Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

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.

Fig. 49-9 Automatrix system. (Courtesy of Dentsply Caulk.)

Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

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 clear matrix system. (Courtesy of Premier Dental Products.)

Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

The 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.

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.

• Sectional matrix with G-rings (retainers) for

postcrior composites

Sunday, October 30,

2016

27

Fig. 49-10 Sectional matrices.

Sectional matrices. (Courtesy of Garrison Dental Solutions.)

Protects and separates Matrix

Protects and separates

Inserts as a wedge Separates during preparation.

Stays in place.

Protects adjacent tooth FenderWedge after use

Protect the adjacent teeth during preparation!

Matrix

Inserts as a wedge Convex matrix shape creates

natural contact point

Tight cervical marginal adaptation

prevents overhang

Flexible wing exerts pressure for maintained

separation and cervical adaptation

• Placed in five seconds

• Jams in and stays in place

• No cervical overhang

• Available in two sizes, Left and Right

• One hand operated organiser box

• Colour coded for easier identification

Matrix

• Placed in five seconds

• Jams in and stays in place

• No cervical overhang

• Available in two sizes, Left and Right

• One hand operated organiser box

• Colour coded for easier identification

Remove FenderMate

using tweezers or pliers Placing by firm pressure