Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD
Transcript of Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD
Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD Dental Matrices
Piece of metal or non-metal which is used to support and give form to the restoration during its packing
and hardening.
Matricing is the Procedure whereby a temporary wall is created opposite to axial walls, surrounding area
of tooth structure that were lost during preparation
Importance of
matrices
1. Serve as a temporary wall during condensation of any restorative material.
2. Give shape and contour to the restoration and prevent marginal overhangs.
3. Maintain the form of the restoration until hardening.
4. Keep the gingival tissues and rubber dam away from the cavity margins during the whole
procedures.
Requirements
1. Easy to adapt to the teeth.
2. Easy to contour
3. Easy to introduce and remove.
4. Smooth and highly polished.
5. Rigid enough to resist condensation pressure.
6. Compatible with the restorative material.
7. Thin enough to not interfere with the tightness of contact.
Types
Classification
Based on mode of retention
1. With retainer, e.g. Tofflemire matrix
2. Without retainer, e.g. Automatrix
Based on type of band
1. Metallic non-transparent matrixes
2. Non-metalic transparent matrixes
Based on type of cavity for which it is used
1.Matrix for class I cavity preparation Double banded Tofflemire (Barton matrix) 2.Matrices for class II cavity preparation
Single banded Tofflemire matrix
Rigid material supported sectional matrix
Ivory matrix no. 1
Ivory matrix no.8
Copper band matrix
Anatomical matrix
Automatrix
3. Matrices for Class III cavities
Mylar strip matrix
S-shaped matrix
4. Matrices for class IV cavities
Custom lingual matrix
Mylar strip matrix
Transparent crown form matrix
Modified S-shaped band matrix
5. Matrices for class V cavities
Window matrix
Cervical matrix
Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD Metallic Matrices
Circumferential Sectional
1. Tofflemire (universal)
2. Automatrix
3. Siquveland
4. T-band
1. Palodent
2. Composi –tight
3. Ivory
4. Strip-T matrix
Ivory Matrix Holder No.1
Provide one proximal wall.
Used in compound class II cavity preparation.
Ivory Matrix Holder No.8
Consists of a band that encircles the entire crown
Used for compound and complex cavity preparation
Universal (Tofflemire) Matrix
Indicated for compound or complex class II restoration.
Provide good stability, anatomic adaptation and ease of insertion and removal.
The Tofflemire matrix assembly consists of the following:
1. Matrix bands
2. Matrix retainer
3. Wedge
Retainer Components Matrix Bands
Made of flexible stainless steel
Available in different thicknesses: 0.001, 0.0015 and
0.002 inch
Available in various occluso-gingival widths.
Pre-contoured bands, dead-soft bands and coated bands
are also available.
Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD Burnishing Matrix Band
1. With band on pad, use small burnisher to deform band.
2. Use large burnisher to smooth band contour.
3. Burnished matrix band used for MOD tooth preparation
Rules of application
1. When the matrix band is folded, the loop will have two circumferences:
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.
The matrix band placed in the slotted side of the retainer is placed gingivally.
The straight retainer placed on the buccal side.
The loop of the band could be placed:
1. Centralized 2. From right 3. From left
Depending on the location of the tooth so that the retainer be parallel to buccal surfaces of teeth and not disturbed by
cheek movement.
Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD Double matrix technique
Indicated when using tofflemire matrix for compound class I (OP / OB)
A piece of stainless matrix material is cut and fitted between the tooth surface and the band a compound coated wedge
is inserted in between and adapted by a burnisher
To provide well-adapted matrix bucally and palataly
Omni-matrix Is a pre-assembled disposable tofflermire retainer and band
Automatrix
It is a retainer-less matrix
It is ready-made bands formed into a circle and are available in three widths
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 lossen the band
Removing pliers are used to cut the band
It is convenient saves time and improves visibility
Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD Copper band matrix
Assorted sizes make excellent matrices
Cylindrical shape
Bands are heated to redness in flame and quenched alcohol
With contouring pliers band is contoured
Festooned with scissors so gingival periphery of it corresponds to gingival curvature and CEJ
To stabilize wedges are placed
Indications Advantages Disadvantages
1. Badly broken tooth
2. Class II with large buccal or lingual
extension
Provide excellent contour Time consuming
Non-patented matrices The Wedged Matrix The Compound Wedged Matrix
Piece of well-contoured band material is cut to slightly
extend past the cavity margins buccally and lingually
and then stabilized in place by means of wooden
wedge.
The same as with the wedged type, but with further
stabilization using modeling compound.
Window Matrix
Universal matrix with the band having custom made trapezoidal hole related to the position of class V as it is
suitable for wide class V cavities with amalgam restoration.
Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD Dental Wedges (Rapid Tooth Separation Method)
Devices that stabilize the matrix band in place during condensation and hardening of the restorative material
Role of wedge
1. Hold the matrix band firmly in position cervically.
2. Prevent marginal overhangs
3. Maintain adequate teeth separation to compensate for the thickness of the matrix to provide tight contact.
Types of wedges
Wooden Wedge Plastic Wedge
Made of orange wood, absorbs saliva and increases in size.
Provide more stabilization to the matrix band with adequate temporary
separation of adjacent teeth.
Could be rounded, triangular, or anatomical.
Color-coded
Available in different sizes.
Wooden wedges better than plastic as it absorb water and increase in size
which potentiate its function.
Anatomical (triangular wedges) are recommended for deeper and / or wider
proximal preparations.
Rounded wedges are recommended for shallower and / or narrower
proximal preparations.
Similar to wooden wedge but made
of plastic.
Color-coded.
Placement of wedges:
1. Length of the wedge should be in the range of 1-1.2 cm.
2. It should not irritate tongue, cheek and gingival tissue.
3. Wedge should be inserted beneath the contact area in the gingival embrasure
4. Usually inserted from lingual embrasure area as it is wider than buccal area.
Operative II Lecture ( 8 ) Dr Ashraf Dr SaGeD Triangular VS Round wedge
Round Wedge of choice in conservative class II, however its wedging action is more Occlusal
Triangular
1. Preparation with deep gingival margin
2. With tofflemire MOD matrix band
3. Deep gingival margin
Modified Triangular
wedge (anatomic wedge)
Modified to conform to the approximating tooth contours
Prevents distortion of matrix contour
Preferred for deeply extended gingival margins
Modified Wedging Techniques
Double Wedging Wedge Wedging Piggyback wedging 2 wedges are used: one is inserted from
buccal embrasure and another is inserted
from lingual embrasure.
Indicated in Spacing between adjacent
teeth where single wedge is not
sufficient
Widening of proximal box in bucco-
lingual dimension.
2 wedges are used
one wedge is inserted from lingual
embrasure area while another is
inserted between the wedge and
matrix band at right angle to first
wedge.
Indicated while treating mesial
aspect of maxillary first premolar
because of presence of flutes in root
near the gingival area.
2 wedges are used, one (larger)
wedge is inserted as used normally,
while the other smaller wedge
(piggyback) is inserted above the
larger one.
Indicated in cases of shallow
proximal box with gingival
recession.
This technique provides closer
adaptation and contour of the matrix
band
العم ساجد ^_^ تم بحمد الله ,,,,,