Tooth separation in operative dentistry

1. 1
MATRIXING AND WEDGING

2. Contact area
 The site of actual contact between two teeth
on the mesial and distal surfaces. It is
erroneously called a ‘contact point’ (Gillmore).
 This is also described as the ‘marble type’ of
relationship.

3. Significance of Contacts and
Contours
 A contact area denotes the area of proximal height of contour of the
mesial or distal surfaces of the tooth that touches its adjacent tooth in the
same arch.
 It is located in the incisal third on central incisors, slightly facial to
centre (faciolingually) and towards the posterior tooth it is located near
the junction of the incisal, middle or occlusal thirds (Figs)
 The contact area is not just a point, but rather a flattened position of
the tooth.
 Contact point refers to the occlusal cusp of a tooth that touches the
occlusal portion of another tooth in the opposing arch. Thus, contact
area and contact points are not the same.
 The location, extent and size of contact area are the key for proper
interproximal relationship.
 The occlusogingival and mesiodistal configuration determines
facial and lingual relationship.
 The contacts and contours are different for different teeth and
different individuals.
 They resist food impaction and are important to the function,
stability and protection of the supporting tissues.

4. Location and extent of contact areas in maxillary dentition

5. Location and extent of contact areas in mandibular dentition.

6. Improper contours may lead to
• Premature failure of restoration
• Periodontal problems
• Caries
• Rotation and drifting of teeth
• Changes in occlusion

7.  Height of Contour.
It is the area of greatest circumference on the facial
and lingual
surfaces of the tooth.
 Gingival Embrasure or Interproximal Space.
It is a triangular space formed by the contact area
of two teeth and the supporting bone.
The size of the embrasure space is determined
according to the shape of the contact area and
location of the bony support.

8. Guidelines Used in Reproducing Contacts and
Contours
1.Proximal contact and contours
2. Marginal ridges
3. Facial and lingual contours

9. Proximal Contact and Contours
 Proximal contour, contact areas and related
structures vary according to the shape of the
teeth.
 According to their general shape, teeth can be
divided into three types:
1. Tapering teeth
2. Square teeth
3. Ovoid teeth

10. Changes as Age Progresses
 With age, surface dimensions of contact area
increase due to abrasion, attrition, leading to
decrease proximal convexities
 As age progresses, the dimensions of the ridge
and occlusal embrasures reduce due to vertical
occlusal attrition and proximal flattening of
contact areas.

11. Marginal Ridges
 A marginal ridge should be compatible to the occlusal cuspal
anatomy creating a pronounced adjacent triangular fossa.
 It should always be formed in two planes buccolingually, meeting
at a very obtuse angle.
 With age, the dimensions of the marginal ridges and the occlusal
embrasures are reduced due to reduced vertical and flattening of
the contact areas.
A marginal ridge is essential for
• The balance of teeth in the arch
• Prevention of food lodgement interproximally
• Protection of periodontium
• Prevention of secondary or recurrent caries
• For efficient mastication

12. Facial and Lingual Contours
Facial and lingual contours and related structures:
 The convex curvature occlusal to the cervical line in all
tooth crowns in a vertical direction is called the cervical
ridge.
 The curvatures on the buccal and lingual surfaces of all
maxillary teeth and on the buccal surfaces of the
mandibular posterior teeth are uniform.
 The average curvature being 0.5 mm or less.
 Mandibular posterior teeth will have a lingual curvature of
approximately 1 mm with the crest of the curvature at the
middle third of the crown.
 Mandibular anterior teeth will have less curvature on the
crown above the cervical line than any other teeth. It is
less than 0.5 mm.

13.  In maxillary anteriors, the concavities are essential
for mandibular movement.
 In maxillary and mandibular anterior, the concavities
reduce the tooth bulk from its gingival third (maximum
dimension) to its incisal third (minimum dimension).
 In posterior teeth, there is a mesiodistal convexity,
corresponding to each cusp.
 Proper mesiodistal contours of the facial and lingual
surfaces of the teeth are essential for the health of
the periodontium.

14. Hazards of Faulty Reproduction of
Physioanatomical Features of Teeth in
Restorations
Contact Size
 Contact area that is too broad buccolingually or
occlusogingivally will change the anatomy of the
interdental col.
 Since the epithelium of the col is nonkeratinized, the
chances of periodontal diseases increase.
 Broadened contact area is susceptible to future
decay as it is difficult for the patient to maintain oral
hygiene.
 If the contact area is too narrow buccolingually or
occlusogingivally, it will lead to food impaction.
There will be greater chances of plaque accumulation

15.  A contact area placed too occlusally will result
in a flattened marginal ridge at the cost of the
occlusal embrasure.
 A contact area placed too buccally or lingually
will result in a flattened restoration at the cost of
the buccal and lingual embrasures.
 A contact area placed too gingivally will
increase the depth of the occlusal embrasures
impinging upon the interdental col.
 A loose (open) contact creates continuity of
the embrasures with each other and with the
interdental col.

16. Contact Configuration
 Creating a flat contact area can make it too broad
buccally, lingually, occlusally or gingivally.
 Excessive convex contact area will reduce the
extent of the contact area predisposing it to the
problems of caries and periodontal diseases.
 A concave contact area usually occurs in restoring
adjacent restoration with a convex proximal
surface.The interlocking between the concavity and
adjacent convexity can immobilize the contacting
teeth, thus, hindering normal physiologic
movements resulting in periodontitis.

17. Contour
1. Facial and lingual convexities:
 Protect the gingival margin by deflecting food
over the gingival margin while allowing stimulation
of the soft tissues enabling them to maintain their
tonicity.
 The over convex curvature can lead to
accumulation of plaque ingredients at the gingival
margin, apical to the height of contour.

18. 2. Facial and lingual concavities:
 Those concavities occlusal to the height of
contour determine the pathways for mandibular
teeth into and out of centric.
 Deficient concavities lead to premature contacts
during mandibular movements.
 Excessive concavities can lead to extrusion,
rotation or tilting of teeth.
 Concavities apical to the height of contour are
required for healthy periodontium.
 Deficient concavities lead to restoration
overhangs.
 Excessive concavities lead to plaque

19. MARGINAL RIDGE
 In the absence of a marginal ridge, there will be
separation of teeth and impaction of food
interproximally, by redistribution of horizontal (H)
and vertical (V) component of forces (Fig).
 Marginal ridge with an exaggerated occlusal
embrasure will lead to separation of teeth and the
vertical food impaction.
 Adjacent marginal ridges not compatible in height:
 With a marginal ridge higher than the adjacent tooth
results in
Contraction of a restoration
Vertical food impaction

20. Forces acting in class II restoration

21.  With a marginal ridge lower than the adjacent
tooth results in similar problems but movement
will be more towards the nonrestored tooth.
 A marginal ridge with no occlusal embrasure:
 The two adjacent marginal ridges will grasp food
substance passing over them.
 Although food debris will not be force
interproximally, but it will be very difficult to
remove the trapped food particles.

22. A one-planed marginal ridge in the
buccolingual direction:
• Can create premature contacts during both
functional and static occlusions.
• The depth of the adjacent triangular fossa is
increased which magnifies stress in this area.
• It increases the height of the marginal ridge in the
centre leading to the adverse effects of the
horizontal components of forces.
• It will deflect the food away from proximal
embrasures.

23.  A marginal ridge without adjacent triangular
fossa results in
• Separation of teeth
• Vertical food impaction
 A thin marginal ridge can fracture or lead to
deformation.
 Marginal ridges not compatible in dimension
or location with the rest of the occluding
surface components lead to similar problems.

24. METHODS OF PRODUCING PROPER
CONTACTS AND CONTOURS
Two operative acts must precede or
accompany the restorative
procedure:
1. Tooth movement
2. Matricing

25. TOOTH MOVEMENT
It is the act of either separating the involved teeth
from each other bringing them closer to each
other and/or changing their spatial position in one
or more dimensions. –Marzouk
Objectives of Tooth Movement
 To create physiologically functional contact, contour
and occlusal anatomy in the restored tooth.
 To bring drifted, tilted or rotated teeth to their desired
physiologic positions.
 To reduce spaces between the teeth.
 To move teeth to another desired location for proper
restoration.
 To extrude or intrude the teeth in order to make them
restorable.
 To move teeth from a nonfunctional to a

26.  To move teeth for better aesthetics after restoration.
 To move tooth to increase the dimensions for resistance
and retention forms of the restoration.
 To create a space which is sufficient for the thickness of
the matrix band interproximally for a positive, tight
contact.
 It can also be used for facilitating access to proximal
cavity preparation especially class III preparations.
 Can be used to detect proximal caries.
 To facilitate adequate polishing of the restoration on
proximal surfaces.
 For easy matrix placement and repositioning of shifted
teeth.
 To remove foreign bodies impacted proximally that are not

27. Classification
Rapid or
immediate
tooth
movement
Wedge
method
Traction
method
Slow or delayed
tooth
movement
Separating
ligature wires
Oversized
temporaries
Rubber dam
sheet
Orthodontic
appliances
Gutta-percha

28. Rapid or Immediate Tooth
Movement
 It is mechanical type of separation which results in
proximal separation at the point of the separator or
closure on the opposite proximal side of the involved
teeth.
 Advantages
• It is quick and predictable.
• More useful and advantageous than slow separators.
 Indications
• Can be used before slow tooth movement.
• To maintain the space which is gained by slow tooth
movement.
• This type of tooth movement should not be more than the
thickness of the involved tooth’s periodontal ligament.
• It should not exceed 0.2–0.5 mm.

29. Wedge Method
Wedge
Method
Elliot
separator
Wood or
plastic
wedges
Separation is done by the insertion of a pointed wedge-
shaped device between the teeth. More the wedge moves
facially or lingually greater will be the separation.

30. Elliot separator
• It is indicated for short duration separation which
does not require stabilization.
• It is used for examining proximal surfaces or final
finishing.
• It is called crab claw separator due to its design.
• It has one bow, two holding jaws and tightening
screw.
• Two holding jaws are placed just below the contact
area.
• Clockwise rotation of tightening screw moves the
contacting teeth.
• Separation should not be more than 0.2–0.5 mm as
greater separation will result in damage of the
periodontal ligament fibres.

32. Wood or plastic wedges
• These are triangular-shaped wedges which are
usually made of medicated wood or synthetic
resin.
• Types of wedges:
1) Wooden wedges
2) Metal wedges
3) Silver wedges
4) Celluloid or plastic wedges
5) Medicated wood wedges

33.  In cross-section the base of the triangle will be in contact with
interdental papillae, gingival to the gingival margin of the
proximal cavity.
 The two sides of the triangle should coincide with the
corresponding two sides (mesial and distal) of the gingival
embrasure.
 The apex of the triangle should coincide with gingival start of the
contact area.

34. Traction Method
 This is done with mechanical devices which engage the
interproximal surfaces of the teeth to be separated by means of
holding arms.
 When moved apart, create separation between the clamped
teeth.
Traction
Method
Noninterfering
true separator
Ferrier double-
bow separator

35. Noninterfering true separator
 Developed by Dr Harry.
 Indicated when continuous stabilized separation is
required during the dental procedure.
Advantages:
 The separation can be increased or decreased after
stabilization.
 The device is noninterfering.

36. Ferrier double-bow separator
 Two bows are there.
 Each bow is placed just below the contact area.
 A wrench is used for turning the threaded bars which
helps in causing separation.
Advantages:
 The separation is stabilized throughout the
procedure.
 The separation is shared by the contacting teeth and
not at the expense of one tooth.

38. SLOW OR DELAYED TOOTH MOVEMENT
 Slow movement of teeth over a period of weeks allows the proper
repositioning of teeth in a physiologic manner.
Indications
 In severely drifted and/or tilted teeth where rapid movement of teeth
to the proper position can endanger
 the periodontal ligament.
Advantage
 Does not damage the periodontal ligament fibres.
Disadvantages
 Time-consuming
 Requires a number of visits

39. Methods for Slow Tooth
Movement
Separating ligature wires:
 A loop of wire is passed beneath the contact
area.
 Ends are twisted to tighten the wire loop for
separation which should not exceed 0.5 mm.
 Twisted wires are bent into the lingual or buccal
embrasures to prevent impingement on the soft
tissues.
 Separation is achieved in 2–3 days.

41. Oversized temporaries:
 Acrylic resin temporary crown which is oversized
mesiodistally helps in achieving slow separation.
 Resin is added on mesial or distal surface to increase
the amount of separation which should not exceed
0.5 mm in one visit
Orthodontic appliances:
 When repositioning of teeth is extensive, the fixed
orthodontic appliances are used.
 This is most effective and predictable method.

42. Rubber dam sheet:
 Heavy or extra-heavy type rubber dam sheet is
used.
 It is stretched and placed between the teeth to
achieve slow separation.
Gutta-percha:
 Gutta-percha is heated and packed into proximal
area.
 For adjoining tooth preparation of posterior teeth.
 1–2 weeks are required for tooth preparation.

44.  Separating rubber ring/band:
Rubber bands are stretched and placed between
the teeth.
It may take 2–7 days for separation.
 Wood.
 Base plate.
 Copper wire.

45. Matrix and Matricing
 Matrix: Matrix is a device which is used to
contour a restoration to simulate a tooth
structure, which it is replacing.
 Matricing: It is a procedure whereby a
temporary wall is created opposite to the axial
walls and surrounding areas of tooth
structure that were lost during preparation.
 It is used with restorative materials that are
introduced in the plastic state.

46. Ideal Requirements of the Matrix Band
 Easy application and removal without any change in
the tooth or the restoration.
 It should replicate the three-dimensional contour of
the future restoration.
 It should be rigid enough to withstand the
condensation pressure.
 It should be fine enough to allow firmness and
contour in the contact area.
 It should prevent gingival extrusion of the alloy and
allow the wedge placement for rigidity and control.
 The material should be cheap and reusable.

47.  It should not move during the setting of the
restorative material.
 It should not react with the restorative material.
 It should be easily sterilized.
 It should not extend more than 2 mm beyond the
occlusogingival height of the crown of the tooth.
 Band depth should be 0.5–1.0 mm gingival to the
gingival margin of the preparation.

48. Parts of Matrix
 The matrix consists of two parts:
1. The band, which is a piece of metal or polymeric
material used to support and give form to the restorative
material during its introduction and hardening.
2. The retainer, which is a device by which the band can
be retained in its proper position and shape.
 The retainer can be a mechanical device, a wire, dental
floss and/or compound.
 Matrices are available as strips of various dimensions.
 They may be 0.001 in. (0.25 mm) or 0.002 in. (0.05
mm) thick.
 The width of the matrix band may be 1/4, 3/8, 5/16 or 1/8
in.
 They are also available as crown forms, split crown
forms, hollow cylinders, and curved bands withnone or

49. Objectives of Matrix
 For proper adaptation of the restorative material, it
should displace the gingiva and rubber dam away
from the cavity margins.
 Assures adequate isolation.
 Provides shape to the restoration during setting of
the restorative material.
 Maintain its shape during hardening of the material.
 Provides a temporary wall of resistance during
introduction of the restorative material.
 Should resist and compensate for the dimensional
change in the material.

50. CLASSIFICATION
 They can be classified in two ways:
1. Based on mode of retention:
a. Mechanically retained matrices, e.g. Ivory matrix
retainer no. 1 and 8, Tofflemire retainer.
b. Self-retained, e.g. copper band, stainless steel
band.
2. Based on transparency:
a. Nontransparent matrices, e.g. stainless steel.
b. Transparent matrices, e.g. cellophane, celluloid.

51. 3. Based on its preparation:
a. Mechanical matrix, e.g. ivory matrix retainer no. 1 and 8.
b. Anatomic/custom-made matrix, e.g. compound supported.
4. Based on the type of tooth preparation for which they are
used:
A. Class I cavity with buccal or lingual extension: double
banded tofflemire matrix(Barton Matrix)
B. Class II tooth preparation, e.g. ivory retainer no. 1,
Nystrom’s retainer.
C. Class II MOD preparation, e.g. Ivory matrix no. 8, Tofflemire
matrix, Steele’s siqveland self-adjusting matrix, anatomical
matrix band, retainerless automatrix.
D. Class III tooth preparation, e.g. S-shaped matrix band,
cellophane matrix strips, Mylar strips.
E. Class IV tooth preparation, e.g. plastic strips, aluminium foil,
transparent crown form, anatomic matrix, custom lingual
matrix, modidied s-shaped band matrix

52. Universal Matrix or Tofflemire
Matrix
 The universal matrix system was designed by BF
Tofflemire.
 It is referred to as universal matrix as it can be
used in all types of tooth preparations of the
posterior teeth.
 The matrix band is fitted into the retainer which is
loosely placed on the tooth and then tightened
into position with the help of screw.
Indications:
 Class I tooth preparation with buccal or lingual
extensions.
 Class II compound tooth preparations.
 Unilateral (MO or DO) or bilateral (MOD) class II

53. Advantages:
• It can be placed on the facial and/or lingual aspect
of the tooth.
• Lingual placement requires the contra-angled
design of the retainer.
• It is economical and sterilizable.
• Stable and sturdy in nature.
• Can be easily removed.
Disadvantages:
• More carving may be required at proximal surfaces
restored using the Tofflemire band.
• Cannot be used in badly broken tooth.
• Does not give optimal results with resin restorations.

54. Tofflemire Matrix System
Components
It consists of
 Retainer
 Band
Parts of the retainer:
 Head
 Slide (diagonal slot)
 Spindle (rotating)
 Set screw

55. TYPES OF RETAINERS
1. Based on type of head:
 Straight – head is straight and it can be placed
from buccal side only.
 Contra-angle – head is angulated and it can be
placed from buccal or lingual side.
2. Based on type of dentition:
 Standard used in permanent dentition.
 Small used in primary dentition.

56. Tofflemire Matrix System Band Types
1. Flat bands:
 Most common types
 Dead soft metal
a. According to multiple shapes and sizes:
 No. 1 (universal band)
 No. 2 (MOD band) – used in molars, has two projections at
gingival edge.
 No. 3 (MOD band) – narrower than no. 2 band.
b. According to the thickness of bands:
 0.010 inch
 0.015 inch
 0.020 inch
 Modifying a flat band with a burnisher or spoon excavator
to establish proper contour.
 Contouring pliers used to contour matrix band.
2. Precontoured bands.

57. Tofflemire Matrix System Band
and Retainer Assembly
Procedure for Placement
 Move the slide so that it is flush with the head of the retainer.
 This can be done by turning the set screw and spindle
counterclockwise.
 The open portion of the head of the retainer should be facing
the operator.
 Continue to turn the set screw in a counterclockwise direction
to completely release the slide so that it is flush with the
head.
 Bring the band to the retainer.
 Check the orientation of the band and the retainer.
 Assemble the two with the open part of the head facing the
operator.
 The shape of the band when it is folded now has taper.

58.  The narrow portion of the band and the open part
of the head of the retainer are always positioned
gingivally.
 Narrow band diameter must be towards the
gingiva.
 Wide band diameter must be towards the
occlusal.
 Open part of the head must be oriented
gingivally.
 After the band is tightly secured into the retainer,
it is placed around the tooth to be restored.
 For final adaptation of the band, the rotating

59.  Procedure for Removal
• Small knot is moved counterclockwise to free the
band.
• The large knot is held and finger is placed on the
occlusal surface to stabilize the band.
• Band is removed moving it in facial and lingual
direction.
• Occlusal surface of the restoration is supported.

60.  Modifications in Tofflemire Retainer
Omni matrix:
 Disposable
 Preassembled retainer
 Available in 0.0010 and 0.0015 in. thick
Advantage: Takes less time.
Disadvantage: Expensive.

61. Matrix Systems
1. Universal or Tofflemire matrix
2. Ivory matrix no. 1
3. Ivory matrix no. 8
4. Automatrix
5. T band matrix
6. S-shaped matrix
7. Anatomical matrix
8. Black’s matrix
9. Soldered band or seamless copper band matrix
10. Steele’s siqveland self-adjusting matrix holder for
tapering teeth
11. Precontoured matrix/Palodent BiTine system

62. Ivory Matrix No. 1
 Indications: It is indicated in unilateral class II cavities.
Features:
 The matrix holder has a claw at one end with two flat semicircle arms
having a pointed projection at the end.
 There is a screw on the other end which on tightening brings both the
claws together.
 The band encircles a posterior proximal surface.
 With a wedge-shaped projection, the band is attached to the retainer.
 The projection engages with the tooth embrasures of the unprepared
surface.
Advantages:
 It is economical.
 Can be sterilized.
Disadvantages:
 It is bulky to apply and remove.

63. Ivory Matrix No. 8
Indications:
 For unilateral or bilateral (MOD) class II cavities.
 For class II complex preparations.
Features:
 The band encircles the entire crown of the tooth to provide
missing walls on both proximal surfaces.
 Matrix band made of thin sheet of metal which can easily
pass through the contact area.
 Circumference of the band is adjusted with the help of screw
present in the retainer.
Advantages:
 It is economical.
 Can be sterilized.
Disadvantages:
 It is cumbersome to apply and remove.

64. Automatrix
Indications:
• Used when unable to place a retainer.
• For extensive class II preparation especially those
replacing two or more cusps.
Features:
• It is a retainer less matrix system.
• Single use.
• Four types of bands are there to fit all teeth regardless
of circumference.
• The bands vary in height from 3/16 to 5/66 inch.
• Bands are supplied in two thickness, 0.015 and 0.02
inch.

65. Advantages:
• The autolock loop can be positioned either on the
facial or lingual surface with equal ease.
• Simple and convenient.
• Less time is taken.
• Increased visibility.
Disadvantages:
• The bands are not precontoured and development of
physiological proximal contour is difficult.
• High cost.
• Difficulty in burnishing.
• Single use.

66. T-shaped Matrix Band
Indications:
• Often used in paediatric dentistry.
• Unilateral or bilateral class II tooth preparation.
Features:
• It is retainerless system.
• It is prefabricated T-shaped brass, copper or stainless steel matrix band.
• Long arm of T surrounds the tooth and overlaps the short horizontal arm of T.
• Wedges and stabilizing compounds are applied to enhance stability.
• One-time use.
• Choices in band width and can be used with permanent teeth as well.
Advantages:
 Simple and economical.
Disadvantage:
 Not stable.

67. S-shaped Matrix
Indications:
• Used for class II design with facial or lingual extension.
• For restoration of distal part of canine and premolar.
Features:
• A regular strip matrix (0.5–1 inch) is used.
• Mirror handle is used to produce the S-shape.
• The contoured S-shaped band is placed interproximally.
• The band is then contoured over the tooth and secured
 with compound on its facial and lingual ends.
Advantage:
 Offers the distal part of the canine and premolar.
Disadvantage:
 Cumbersome to use.

68. Anatomical Matrix
 Indications:
 Indicated for class II restorations unilateral or bilateral.
 Mutilated teeth or teeth requiring reproduction of unique
anatomy
Features:
 Most efficient means of producing contacts and contours.
 First described by Sweeney.
 Entirely handmade and contoured specifically for each
individual tooth.
 Has sufficient rigidity.
 Buccal and lingual embrasures are sealed with compound.
 A piece of 0.001–0.002 inch stainless steel matrix band 1/8
inch in width is drawn between the handle of a pair of
festooning scissors.
 The matrix is then cut to proper length and then contoured.
 Wedge is selected and shaped according to the gingival
embrasures.

69.  Matrix is now ready for condensation of the
restorative material.
 After insertion and hardening of the restorative
material, compound cone and wedges are removed
followed by the matrix.
Advantages:
 Easy to remove.
 Gives better contact and contour in restoring class II
tooth preparation.
 Has adequate rigidity.
 Recontouring is possible after compound placement.
Disadvantage:
 Time consuming.

70. Black’s Matrices
 Indications:
 Used for simple and small sized cavities.
Features:
 A metallic band is cut so that it will extend just beyond
the buccal and lingual extremities of the cavity
preparation. To prevent wrap around holding ligature
from slipping and band sliding gingivally, the corners
of the gingival ends are turned up.
• Black’s matrix with a gingival extension is also
available to cover the gingival margin of the
subgingival cavity.
• The ligature should be secured tightly with a surgical
knot after wrapping it around the tooth.

71. Soldered Band or Seamless Copper
Band Matrix
 Indications:
• Indicated for badly broken down teeth, e.g. pin-retained restorations with large
extensions.
• Severely damaged down teeth with large buccal and lingual extension.
 Features:
• A stainless steel band is cut according to the shape of the crown and two ends
are soldered together.
• Alternately seamless copper band is selected which barely clears the
diameter of the cervical area of the tooth.
• The band is heated and then quenched in alcohol for softening the band for
easier placement.
• The band is festooned and contoured with contouring pliers according to the
shape of the tooth.
• The band is then seated and tightened at the cervical end by pinching up a
tuck using a flat bladed plier.
• To stabilize the band, the wedges are placed below the cervical margin of the
preparation.

73. Steele’s Siqveland Self-adjusting
Matrix Holder for Tapering Teeth
 Indications:
• Used when there is difference in occlusal and cervical
diameter of the teeth.
• For all compound and complex preparations in
posterior teeth.
 Features:
• This type of matrix retainer can provide two different
diameters at the two ends of the band.
• A movable slide holds and tightens the band in
required position.
Advantages:
• It can adapt to tooth contour.
• Adaptation of band is possible without the help of
wedges.

75. Precontoured Matrix/Palodent
Bitine System
Indications:
 Used for class II compound or complex tooth
preparation.
Features:
• Precontoured matrix is made up of soft metal.
• Wedge is used to separate the teeth and hold the
sectional matrix in position.
• The ring is held with the rubber dam forcep.
• Beaks are placed into the embrasures of the preparation
side.
• Ring tightly seals the sectional matrix around the tooth.
• Matrix band is contoured with ball burnisher.
• Wedge is inserted below the contact area.
• The restoration is then accomplished.
• Ring and wedge are removed after the restoration.

76.  Advantages:
• Simple and easy.
• Better contours are achieved.
 • Provide tooth separation.
 Disadvantages:
• Tight contacts may hinder with band insertion.
• Expensive.

77. Matrices for Class III Direct Tooth-coloured
Restorations
1. Matrices for class III direct tooth-coloured
restorations with teeth in normal alignment :
• The suitable plastic strip is burnished to proximal contour
of the tooth.
• The strip should be cut as wide as the tooth is long.
• The length of the strip should be just sufficient to cover
the labial and lingual surfaces of the teeth.
• A wedge is trimmed and applied to hold the strip in place.
• Wedges are introduced from the side opposite to that of
the access.
• After insertion of the material, reflect the free end of the
strip and hold the whole strip firmly against the setting
restorative material using the thumb and first finger of the

78. 2. Matrix for class III preparation in teeth with irregular
alignment:
• A plastic strip is contoured and adapted and removed as
mentioned above.
• For a labial approach, a compound impression is made of
the lingual surface.
• The compound should overlap the adjoining teeth.
• The excess of the compound impression from the cavity is
trimmed off to produce a flat surface.
• The strip is then placed into position again, followed by
the compound impression against the strip, assuring a
perfect adaptation of the matrix to the cavity on the
lingual surface.
• The material is then introduced from the labial.

79. 3. Matrix for two small proximal preparations in
contact with each other:
• A plastic strip is folded with one end slightly longer
than the other to permit their separation after the
insertion of the strip between the teeth.
• A loop 1/2 in. in diameter is made in the matrix strip.
• This loop is flattened and made into a T shape.
• The trimmed T-shaped matrix is then placed between
the teeth.
• After insertion of the restorative material, the strip is
folded over the material till it is set.

81. Matrices for Class IV Preparations
for Direct Tooth-coloured Materials
 Plastic strip for incisoproximal cavities:
• Cellulose strips are used for silicate cements.
• Cellophane strips are used for resins.
• Mylar strips are used for composite and silicate
restorations.
• A suitable plastic strip is folded at an angle into an L
shape and then sealed with plastic cement.
• One side is cut so that it is as wide as the length of the
tooth.
• The angle formed should approximate the normal
corner of the tooth.
• The cavity is then filled and the strip is held with the
thumb.
Advantages: Simple, easy and economical.
Disadvantage: Lacks stability.

82. 2. Aluminium foil incisal corner matrix:
• These are stock metallic matrices which are shaped
based on the proximoincisal corner and surface of the
anterior teeth.
• Cannot be used for light-cured resin.
• A corner matrix closest in size and contour is selected.
• The matrix is trimmed gingivally so that it covers the
gingival margin of the preparation.
• It is shaped with the thumb and first finger until it fits
the mesiodistal and labiolingual dimension.
• Partially fill the preparation and the corner matrix after
venting the corner.
• Apply the partially filled matrix over the partially filled
tooth preparation at its predetermined location

83. 3. Transparent crown form matrices (Fig. 10.16)
 These are stock plastic crowns which can be
adapted to tooth anatomy.
 Indications: In bilateral class IV the entire crown
is used and for unilateral class IV half of the
crown is used.
 Advantages:
• This is easy to use
• Gives better contours.
 Disadvantages: Time-consuming and costly.

85. 4. Anatomic matrix:
• Before preparing the teeth, study model for the tooth
with at least one intact adjacent tooth is made.
• Restoration of defective areas is done on the study
model in a fairly heat-resistant material to correct
configuration.
• Plastic template is made, and trimmed gingivally to
proper fit.
• The restorative material is placed into the preparation;
the matrix is filled with material and inserted over the
prepared and partially filled tooth.
Indications: For restoring class IV preparations.
Advantages: Simple to use and gives better contours.
Disadvantages: Time-consuming and costly.

86. Matrices for Class V Preparation
for Direct Tooth-coloured
Restorations
1. Anatomic matrix for non-light cured direct tooth-
coloured material.
2. Aluminium or copper collars.
3. Anatomic matrix for light and non-light cured
direct tooth-coloured material

87. 1. Anatomic matrix for non-light cured direct tooth-
coloured material:
• The class V cavity is initially filled with inlay wax or
gutta-percha and finished to the proper contour.
• The wax and the tooth are coated with cocoa butter on
Mylar strip.
• The compound impression is made of the tooth surface
to the restored.
• Adjacent surfaces are to be included in the impression.
• After the compound has cooled, it is removed and the
wax or gutta-percha is removed from the cavity.
• The restorative material is placed into the cavity.
• The compound matrix is placed into position and held
securely in place until the material sets.

88. 2. Aluminium or copper collars for non-light cured
material:
• Aluminium or copper bands are preshaped
according to the gingival contour of the tooth.
• Band covers 1–2 mm of the tooth circumferential
to the cavity margins.
• Cavity is filled with the restorative material and
allowed to set.

89. 3. Anatomic matrix for light and non-light cured
materials:
• Same as class IV anatomic matrix.
• After restoring the defects on study models,
plastic template is made.
• The template is cut and used as a matrix.

90. WEDGES
90

91. Wedges are small, tapering,
triangular pieces of, wood or clear
plastic about
½ inch in length
91

92. WEDGE
PLACEMENT
92

93. WEDGE
PRINCIPLE
93
Mechanical method of tooth
separation where a wedge or
conical shaped device is inserted
between adjacent teeth beneath the
contact area of teeth which leads to
separation.

94. wedges
wooden plastic
Triangular
round
94
Light transmitting

95. SIZE & SHAPE
95
SIZE:- ½
inches(1.2cm)
Wedges are available in
various sizes, which
may be color coded.
They are either plain
(straight) or
anatomically
(triangular)shaped

96. 96

97. MODE OF INSERTION
97

98. POSITION &
PLACEMENT
98
As near to the gingival cavosurface
margin as possible
Not only stabilizing the matrix but more
importantly it is placed below gingival
cavosurface margin to prevent amalgam
from flowing below the cavo surface
margin.

99. CORRECT & INCORRECT
WEDGE
POSITION
99

100. WEDGING
TCHNIQUES
1. Single wedge technique
100

101. 2. PIGGY BACK
WEDGING
101
 Useful for the
patients with
gingival recession
 Wedge is significantly
apical of the gingival
margin a second
wedge may be
placed on top of the
first

102. 3.DOUBLE
WEDGING
102
 One from lingual
embrasure and one
from facial
embrasure
 Only if middle 2/3 of
proximal margin can
be adequately
wedged.
 When proximal box
is wide facio
lingually

103. 4.WEDGE WEDGING
103
 Mostly employed
on mesial aspect
of maxillary I
premolar,
because of fluted
roots(concavity)
 Second pointed
wedge is inserted
between the first
wedge and the band,
to wedge a matrix
band tightly in such a
margin

104. TRIANGULAR VS ROUND
WEDGE
104
 Round: is a 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

105. MODIFIED TRIANGULAR
WEDGE
(anatomic wedge)
105
 Modified to conform to the approximating tooth contours
 Three-dimensionally shaped to follow the contour of the
tooth.
 Prevents distortion of matrix contour
 Preferred for deeply extended gingival margins
 Follows the anatomy of the tooth to create less tissue
irritation and postoperative discomfort

106. REFERENCES
106
Operative dentistry : STURDEVANT’S
Operative dentistry : JAMES B.
SUMMITT
Operative dentistry : M.A. MARZOUK

107. 107