AN OVERVIEW ON VARIOUS MATRICING SYSTEMS

Dr. EHSAN SANJABI

INTRODUCTION •Matricing is the procedure whereby a temporary wall is created opposite to axial walls, surrounding areas of tooth structure that were lost during preparation

INTRODUCTIONThe first successful matrix was introduced in to dentistry by Dr. Louis Jack in 1871.

A dental matrix may be defined piece of properly shaped material which forms the missing wall of the restoration which gives form and shape to the restoration during insertion and condensation of restorative material

Functions & objectives• Replaces the missing wall• Forms point of contact with adjacent tooth• Permits adequate condensation• Prevents cervical overhang of restoration• Possess exact 3D contour of future restoration

• Maintains shape during hardening of material

Qualities of a good matrix• •Rigidity• •Establishment of proper anatomic contour

• •Restoration of correct proximal contact relation

• •Prevention of gingival excess• •Convenient application & ease of removal

Specifications•Position of the matrix- It should always be 1 mm below the gingival seat and 1 mm above the marginal ridge.

• Thickness of matrix band - 0.002 or 0.0015 inch thickness

Problems associated with faulty reproduction of contacts and contours

• Food impaction /retention

• Gingival recession Gingival inflammation

• Fractured restoration

Drift)• Faulty occlusion

• distal migration of untreated tooth

• Gingival irritation • Periodontal complication

• acute abscess or bone loss.

• Shifting of teeth

Components of a Matrix System

•Band - which is a piece of a metal or polymeric material used to support and give form to the restorative materials during its introduction and hardening.

Band

Components of a Matrix System

•Matrix retainer - is a device by which band can be retained in its designated position and shape. The retainer could be a mechanical device, a wire, dental floss or a compound

Matrix retainer

Components of a Matrix System

•Wedges – Wedges are used interdentally to ensure close adaptation of the matrix band with the gingival seat of prepared proximal cavity

Wedges

WEDGES device that create rapid seperation during tooth preparation and restoration

FUNCTIONS OF WEDGES

1. assure the close adaptability of the matrix band to the tooth ,

2 they prevent the restorative material from impinging on gingival embrasure thus ensuring proper health of the interdental papilla.

3. They define the gingival extent of the contact area as well as the facial And the lingual embrassure .

4. They separate teeth to compensate for the thickness of the matrix band.

5. Atraumatically retract the rubber dam and gingiva from the gingival margins of proximal tooth preparations there by producing a temporary hemostasis.

6. Assure the immobilization of the matrix band arranged facial-lingually and cervico-occlusally during insertion of restorative material.

7.Prevent gingival overhang of restorations

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TYPES OF WEDGES Wooden wedges Plastic wedges

WOODEN WEDGESAre made from soft wood like pine or hard wood like oak

Usually preferred as : They are easy to trim Adapt well Absorb moisture and swell to provide adequate stabilization to the

matrix band

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TYPES OF WEDGE

Triangular wedge: preferred for the cavities with deep gingival margins.

Round wedges: Preferred in ideal class II preparations as the wedging action is closer

to the gingival margin.

PLASTIC WEDGES:They are used with either transparent matrices or metal matrices .

However they cannot be trimmed and thus cannot be custom fit.

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LIGHT TRANSMITTING WEDGES:

Are special plastic wedges which are transparent and have a light reflecting core.

Used with class II composite restorations

They can transmit approx 90-95% of the incident light ,drawing the curing light to the gingival margin of the restoration thus directing a polymerization shrinkage towards the margins.

Therefore these wedges are helpful in providing better marginal adaptation at a cervical areas of classic composite resin restoration.

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SPECIAL WEDGING TECHNIQUES

1. PIGGY BACK WEDGING :

In situations where there is gingival recession and the proximal box is shallow gingivally a single wedge may be very much apical to the gingival margin. In such cases a small wedge “piggy back” is used over the first wedge to ensure proper contour.

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DOUBLE WEDGING:In this techniques two wedges, one from the buccal aspect and one

from the lingual aspect are used to provide close adaptation of the matrix band at the cervical aspect of the tooth.

Indicated for wider proximal box in buccolingual dimensionsAnd for spacing between the adjacent teeth.

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WEDGE WEDGING:employed primarily on the mesial aspect of the maxillary first premalor as these

teeth have concave areas in the root near the gingival margins.So placing a single wedge may still leave an open margin gingivally .Therefore a second wedge can be inserted between the first wedge and the

band so that this opening is eliminated. and the matrix band is well adapted to the gingival margin of the prepared cavity.

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Classification of matrices according to the tooth Preparation for which they are used

I. Posterior matrices

I - A)Matrices used for missing more than one wall (Continuous matrix:) a-Matrix tensioning system a1-Tofflemire a2-built-in retainer system i. Omni matrix (disposable, pre assembled). ii. Automatrix iii. Super Mat Matrix System and ReelMatrix iv. Maximat Plus iiv. Lucifix matrix

b-Retainer less matrix b1-Denovo system ( pre-welded S.S bands), b2-Copper band b3-T-band

I - B)Missing one proximal wall only(sectional matrix)1-Ivory matrix no 12-Clip matrix 2.a Darway system(palodent) 2.b Palodent plus 2.c Tri-clip 2.d V-Ring: 2.e Garrison Ring 2.f Omni-Matrix Sectional3-Walser matrices4-Black's matrices

II-Anterior matricesA) Cervical matrix i. Transparent cervical matrix (blue view ii. 360° Cervical Matrix

B)CLASS III & IV matrices

Evolution of matrix systems

•Black’s matrices•Ivory matrix system•Tofflemire matrix•Anatomic & Automatrix•Sectional matrices and contact ring systems

Black’s matrices

• The blacks matrix is one of the early custom made matrices. Introduced in 19 th century. It consist of thin strip of stainless steel metal placed on the proximal surface and then tied around the tooth with dental floss or ligature.

Black’s matrices

Soldered band or seamless copper band

• Indicated for badly broken down teeth especially those receiving pin retained amalgam restorations with large buccal and lingual extensions.

Soldered band or seamless copper band

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Ivory number 1 and 8

IVORY NO. 1

IVORY NO. 8 MATRIX

Tofflemire matrix:

Tofflemire matrix:•Different sizes,shapes

Tofflemire matrix:

Automatrix• 1. Band is self retained by holding one end of the band and rolling the other end over itself, decreasing the band length and consequently, the matrix diameter until it fits tightly over the tooth and preparation.

• 2 Ratchet is used to clinch the band securely to the tooth.

• 3. Wedging not usually required. • 4. Removed in angular direction

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Sectional matrices and contact ring systems •The McKean principle of separation is based on equal and opposite forces exerted on the contacting teeth by the tines of the ring. The force vectors can be resolved into mesial and distal components, these components providing separating forces.

•

Sectional matrices and contact ring systems • The separation is time dependent phenomenon with the separation increasing with time. When the contact ring is removed after composite placement and curing, the tooth returns to its equilibrium position. The space taken up by the sectional matrix is eliminated

Some systems based on the McKean concept are available•Contact Matrix (Danville Materials)•Palodent BiTine and PALODENT PLUS

•Composi -Tight (Garrison dental solutions)

Contact Matrix (Danville Materials)

Contact Matrix (Danville Materials)

Contact Matrix (Danville Materials)

Contact Matrix (Danville Materials)

Contact Matrix (Danville Materials)

Palodent by dentsply

Palodent by dentsply

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Palodent plus

Palodent plus

U N I V E R S A L R I N G

N A R ROW RING

MAT R I X B A N D

WE D G E

Composi -Tight

WE D G E G U A R D FOR C E P S

Composi -Tight

Composi -Tight

Composi -Tight

Composi -Tight

Composi -Tight

Composi-Tight 3D Clear Sectional Matrix System

3M Sectional Matrix Plus Retainer System and Wedges

SUPERMAT MATRIX SYSTEM - Kerr

FenderMate by JS Dental

Bioclear Matrix Systems

THIS IS NOT GOOD!!!!!!

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