What is a Matrix Band ? Types of matrix bands. characteristics of a good matrix. Functions. uses of matrix bands. Toffelmire, Ivory #1 & #8 matrix band. Wedges Role of a wedge. Modification of a wedge. Conclusion.

1. 1
MatricesinOperativeDentistry

2. 2
Matrix ?
A matrix is device that is applied to a
prepared tooth before the insertion of a
restorative material to assist in the
development of the appropriate axial tooth
contours and in order to confine the
restorative material excess.

3. Clinical Note: The matrix usually is
applied and stabilized with a wedge
before application of the restorative
material

4. Why doweneedmatrices ?
4
 Gingivalfloorof aclassII
cavityisthemost
vulnerableareawhere
overhang of restorative
materialcantakeplace.
 Thereisnomethodto
controltheplacementand
contourof restoration
withoutamatrixwall.

5. Characteristicsofagood matrix
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 Rigidity.
 Establishmentofproperanatomicalcontour.
 Restorationofcorrectproximalcontact relation.
 Easy adaptationtothe tooth.
 Abilitytobecontoured.
 Preventionofgingival excess.
 Strengthtoofferresistancetocondensation.
Pressure during restoration.
 Easy ofremoval.

6. Functionsof matrix
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 Provisionofatemporarywallofresistance to
thepressurenecessaryforamalgam insertion.
 Provisionofshapeandcontourtothe
restoration.
 Maintenanceofformduringplacement and
setoftheamalgam/composite.

7. Classification
7
 On thebasis of modeofretention.
• Withretainer.E.g.toffelmirematrix
• Withoutretainer.E.gautomatrix
 On thebasisoftypeofband.
• Metallicnontransparentmatrix
• Nonmetallictransparentmatrix

8. On the basis of type of cavity
for which it is used.
• Class 1 cavity prep.
o Double banded tofflemire (barton
matrix)
• Class 2 cavity prep.
o Single banded tofflemire matrix
o Ivory matrix no. 1
o Ivory matrix no. 8
• Class 3 cavity prep.
o Mylar strip matrix
o S-shaped matrix

9. • Class 4 cavity prep.
o Custom lingual matrix
o Mylar strip matrix
o Modified s-shaped band matrix
• Class 5 cavity prep.
o Window matrix
o Cervical matrix

10. Metallic matrices
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Ivory typeTofflemire type
T-band (straight) Curved T-Band

11. Tofflemirematrix band
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 AlsocalledasUniversalMatrix
 TheTofflemirematrixassemblyconsists ofthe
following:
 Matrix bands
 Matrix retainer
 Wedge

12. Indications:
• Tofflemire matrix is ideally indicated when
three surfaces (i.e. mesial, distal and
occlusal) of a posterior tooth have been
prepared
• It also is commonly used for the two surface
class 2 restoration.

13. Advantages:
• May be positioned on facial and lingual aspect of
the tooth.
• The retainer and band are generally stable when
placed.
• The retainer is separated easily from the band.
• Matrix bands of various occlusogingival width are
available.
• A small Tofflemire retainer is available for use with
primary dentition.
• When cotton roll isolation is used, The tofflemire
retainer holds the cotton roll in place

14. TypesofBands:
14
 Thenon-contouredbandsareavailablein
twothicknesses,0.05mmand 0.038mm.
 Precontouredmatricesmayhave
variable dimensions(dependinguponthe
commercial product).

15. Advantagesofpre-contouredbandsover
non-contouredbandsistheyneedlittleorno
adjustmentbeforebeingplacedintheretainerorafter
beingpositionedaroundthetooth.
Requirelesschairtime.
Disadvantage:Expensive

16. Matrixbands
•.
16

17. Assembled bands
17
Fig 12-6

18. ClinicalTechnique
18
 Shaping the matrix
• The flat tofflemire matrix band must be
shaped (burnished) to achieve proper
contour and contact
• Burnishing must occur in areas
corresponding to the proximal surfaces
to be restored.
• The no.26-28 burnisher is generally
recommended for burnishing the band.
• The band should be placed on a resilient
paper pad.

19. The smaller round burnisher tip
should be used initially with firm
pressure in back and forth and
overlapping strokes along the
length of the band.
This is done until the band is
deformed occluso-gingivally.
The larger burnisher is then used
to smoothen the surface of the
band contour.

21. Preparing the retainer to receive the
band
 Step 1: The larger of the knurled nuts is turned
counter clockwise.
 Step 2: while holding the large nut, turn the small
knurled nut counter-clockwise.
 Step 3: the matrix band is folded end to end
producing smaller circumference on the gingival
end than the occlusal surface.

22. Step 4: the band is positioned in the
retainer so that the slotted side of
the retainer is directed gingivally to
permit easy separation of retainer
from the band in an occlusal
direction
Step 5:The band is placed in the slot
and the smaller of the knurled nuts
is turned clockwise to tighten the
band.

24. Assemblyoftofflemire retainer
24

25. Technique
25

26. Placing the band with retainer on
the prepared tooth.
 Step 1: The matrix band is fitted around the tooth (gingival
edge of the band is positioned 1mm apical to the gingival
margin)
 Step 2: The larger knurled nut is rotated clock-wise to
tighten the band slightly.
 Step 3: All aspects of the band are assessed. Final
corrections are made after wedging.
 Note: the matrix band should touch the adjacent contact
area.

27. Technique
27

28. Removal of the band with retainer
 Step 1: The small knurled nut is rotated counter-
clockwise
 Step 2: The matrix is removed after hardening of the
amalgam to avoid fracture of the marginal ridge during
band removal.
 Step 3: The band is pushed or pulled in the linguo-
occlusal direction and if possible, in the direction of wedge
insertion. A straight occlusal direction should be avoided.
 Step 4: The wedge is removed after separating the matrix
band from the tooth.

29. Wedges
29
 Anatomical(triangular
wedges)are
recommendedfordeeper
and/ orwiderproximal
preparations.
 Roundedwedges are
recommended for
shallower and / or
narrower proximal
preparations.

30. Wedges
30

31. Role of wedge
31
 It should hold the matrix band firmly in
position cervically.
 It should not be of such a height that it
prevents the formation of a contact point.
 Another function is to separate the teeth
slightly so that when it and the matrix are
finally removed, the teeth return to their
original positions, closing the small space left
by the thickness of the matrix band.

32. Modificationof matrices
32
All matrices require modification when:
 proximal surface is a guide plane for
tooth/ tissue supported partial denture.
 Adjacent tooth has a flatter contact.
 Adjacent proximal contours are not
normal.

33. Automatrix
 Narrowregular(4.7mm), (0.05mm)
 Wide regular(7.9mm), (0.05mm)
 Mediumthin(6.2mm), (0.038mm)
 Mediumregular(6.2mm),(0.05mm)
33

It’sa retainer less matrixsystem with
four types of bands, designed tofit all
teeth regardless of circumference.





34. Preformed Matrix Bands
34

35. Arematricesreusable??
35
.
Re-use of matrix bands is common.
Guidelines for the safe re-use of matrix bands
are required.

36. Conclusion
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 The role of matrices in operative
dentistry is irreplaceable.
 Without a matrix there is no other way (in
a directly placed restoration) to produce
contours and contacts.
 No matrix band is ideal, almost all
proximal cavities need a matrix depending
on the requirements of the specific case.

37. Thank You…