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.
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DIFFERENT MATRIX BANDS AND RETAINERS
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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
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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)
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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
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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
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2016
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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