contact and contours

 INTRODUCTION
 BENEFITS OF HAVING IDEAL CONTACT &
CONTOURS
 DEFINITION
 TYPES OF CONTOURS
 HEIGHT OF CONTOUR
 CONTACT AREA BETWEEN
INCISORS,CANINES & BICUSPIDS
 MARGINAL RIDGES
 EMBRASURES AND SPILLWAYS
 PROCEDURES FOR
FORMULATION OF PROPER
CONTACTS & CONTOURS
 TEETH SEPERATION –RAPID &
SLOW/ DELAYED
 WEDGES & MATRICES
 HAZARDS OF FAULTY
REPRODUCTION OF CONTACT &
CONTOURS
 RECENT ADVANCES IN CONTACT
& CONTOURS

Over millions of years of evolution the teeth have gradually developed a specific
shape, with fundamental curvatures at certain areas on each tooth representing
successful adaptation towards the maintanance of the teeth within the dental
arch.
From the cariogenic aspect there may be only twenty occlusal surfaces but there
are sixty contacting proximal and 64 facial and lingual surface that are
susceptible to decay
INTRODUCTION

 Decay on the proximal however, occurs mainly due to the faulty inter
relationship between the contact area, marginal ridges, embrasures and
the gingiva.
 Presence of proper contact and contour is important to maintain stability
& occlusal harmony

 A thorough knowledge of the contact and contours of various teeth is mandatory for
understanding
 Predisposing factors of proximal caries like faulty interrelationships
 Significance of marginal ridges,embrasures for re-establishing the form and function of
restored teeth
 Periodontal aspect & health of the tooth to be restored

Benefits of an ideal contact & contour
1. Conserves the health of peridontium
2. Prevents food impaction
3. Makes area self cleansable
4. Improves longevity of proximal restorations
5. Maintains normal mesiodistal relationship of the teeth in the dental arch

Role of a dentist is to establish the ideal extension so as to perform optimal
functions,maintaining the integrity and longevity of individual tooth

DEFINITION
Proximal contact area: it denotes the area of proximal height of contour of mesial
or distal surface of the tooth that touches its adjacent tooth in the same arch.
Contours: the vertical curvatures on the facial and lingual surfaces.
Contours of anterior teeth are present in cervical third and that of posteriors is
present on middle third.

TYPES OF CONTOURS
All teeth have some specific convexity on the facial,lingual,proximal and occlusal
surface of teeth that afford the protection and stimulation of the supporting tissues
during mastication.This convexity are called contours.
TYPES
 FACIOLINGUAL CONTOUR
 PROXIMAL CONTOUR
 OCCLUSAL CONTOUR

CONTOURS ON THE FACIAL & LINGUAL SURFACE
 Facial surface-cervical one third of all teeth
 Lingual surface-cervical one third of incisor and canines
Middle one third of the premolar and molar

 The height of contour of the buccal surfaces of
the posterior teeth is located in the gingival
third
 The height of contour of the lingual surface of
posterior teeth is located in the middle or
occlusal third
 The average curvature is around 0.5mm with
mandibular posterior having a lingual
curvature of 1mm
 Mandibular anteriors having curvature of less
than 0.5mm

I. Proximal contour,contact areas & related
structures
 According to their general shape, teeth can
be divided into 3 types :
 Tapering teeth.
 Square teeth.
 Ovoid teeth.

ANATOMICAL FEATURES OF CONTACT AREAS
• Contact starts at incisal ridge incisally and little towards labially
TAPERING
(WIDE CROWNS &
NARROW CREVICES)
• Starts at incisal ridge incisally & in line with it labiolingually
SQUARE
(BOXED)
• Slight lingual to incisal ridge labiolingually
• Mesial contact starts at 1/4of crown incisogingivally
• Distal contacts starts 1/3rd to ½ of crown incisogingivally
OVOID
(TRANSITIONAL)
INCISORS

• Mesial contact at the incisal ridge
• Distal contact near the middle
• Very angular
Tapering
[wide crowns and narrow
crevices]
• Close to incisal ridges incisally.
• In line with them labio lingually
Square
[Boxed]
• Same as square type
Ovoid
[Transitional]
CANINES

• Buccal periphery almost at buccal axial
angle (buccal third) of the tooth.
• Occlusal periphery at the junction of
occlusal and middle third of the tooth.
Tapering
[wide crowns and
narrow crevices]
• Buccal periphery more towards buccal axial
angle (buccal third)
• Occlusal periphery is at occlusal third.
Square
[Boxed]
• Convexity of MR carries occlusal periphery
towards middle 3rd.
• Buccal periphery at the junction of buccal
and middle third
Ovoid
[Transitional]
BICUSPIDS

• Buccal periphery almost at the buccal axial
angle of the tooth.
Tapering
[wide crowns and
narrow crevices]
• Same as premolar
• Extension lingually stops in the middle third
(1-4mm)
Square
[Boxed]
• Same as bicuspids
Ovoid
[Transitional]
MOLAR MESIAL

• Buccal periphery at the middle third
• Occlusal periphery at the middle third.
Tapering
[wide crowns and
narrow crevices]
• More lingually deviated than the mesial but
not to the extent of the tapering teeth.
Square
[Boxed]
• Buccal periphery in line with the central
groove in the occlusal surface.
Ovoid
[Transitional]
MOLAR DISTAL

Marginal ridges
• They are elevated rounded ridges located on the mesial and distal edges on the
occlusal surface of the tooth”.
• Occlusal cuspal anatomy.
• Triangular fossa.
• Two planes bucco-lingually.

A marginal ridge with these specifications is essential
for :
 The balance of the teeth in the arch.
 Prevention of food impaction proximally.
 Protection of the periodontium.
 Prevention of recurrent and contact decay.
 For helping in efficient mastication.

 Curvature formed by two adjacent
teeth in an arch form a spillway space
that is called an embrasure
Serves 2 purposes
• Provides a spillway for passage for
food during mastication
• Prevents food from being forced into
the contact area

PROCEDURES FOR FORMULATION OF PROPER
CONTACTS AND CONTOURS
I . Tooth movements.
II. Matricing

Tooth movement
History:
A.O. Jarvis (1874)
Dr. Safford, G. Perry and
W.I. Ferrier.

OBJECTIVES:
1. To bring drifted, tilted and rotated teeth to their physiologically indicated
positions to maintain natural contacts and contours.
2. To close the space between the teeth which is not closed by restorative
methods.

3. To move the teeth in order to improve the health of periodontium.
4. To move the teeth apically (intrusion) and occlusally (extrusion) to make them
restorable.
5. In order to expose the proximal surface to polish proximal restorations.
6. To change the position of teeth from non-functional or a traumatically
functional position to a physiological functional position.

7. To detect proximal caries which is not detected by conventional methods.
8. To create a space sufficiently for the thickness of the matrix band inter-
proximally.
9. To remove foreign bodies collected between teeth which is not removed by
floss, brush or explorer.

Two principle methods of tooth movements /
separation:
 1. Rapid or Immediate tooth movement / Separation.
 2. Slow or Delayed tooth movement / Separation.

Rapid or Immediate Separation/Tooth
movement
 This is a mechanical type of separation that creates, either proximal
separation at the point of the separators introduction and / or improved
closeness of the proximal surface opposite the point of the separators
introduction.

Advantages of Rapid Separation:
• Procedure is quick and stable
• Most valuable & frequently used
• More advantageous than slow separation method
Disadvantage:
• Chances of rupturing Pdl fibers is more and also rapid separation may induces pain or
soreness.

Rapid separation is achieved by two principles:
1. Wedge principle
2. Traction principle

CONTENTS
 PRINCIPLE
 DEFINITION
 TYPES
 FUNCTIONS
 WEDGING TECHNIQUES

1. Wedge principle:
 Separation is achieved by placing pointed wedge shaped device between
the teeth and slowly inducing pressure in order to create space at the
contact area.
 Ex: Elliot’s separator, Wedges.

WEDGES
Device that create rapid separation during tooth preparation
and restoration

TYPES OF WEDGES
 Wooden wedges
 Plastic wedges
WOODEN WEDGES
Are 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

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.

LIGHT TRANSMITTING WEDGES:
 Are special plastic wedges which are transparent and have a light reflecting
core.
 Used with class II composite restorations
 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
cervical areas of classic composite resin 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

SPECIAL WEDGING TECHNIQUES
 PIGGY BACK WEDGING
 DOUBLE WEDGING
 WEDGE WEDGING

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
to ensure proper contour.

 DOUBLE WEDGING:
 In this techniques two wedges, one
the buccal aspect and 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 dimensions
 And for spacing between the adjacent
teeth.

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.

Traction principle:
 This is achieved by a mechanical device which engages proximal surface of teeth to be
separated by means of holding arms and then separation is achieved between the
clamped teeth.
 Ex: Non-interfering true separator,

SLOW OR DELAYED TOOTH MOVEMENT
 Indications :
1.When the teeth have drifted or tilted or rotated to a considerable extent and
rapid separation will endanger the periodontal ligament .
2. Slow tooth movement over a period of weeks or months will allow proper
repositioning of the tooth in a physiologic manner .

METHODS
 SEPARATING LIGATURE WIRES
 OVERSIZED RESIN TEMPORARY CROWNS
 ORTHODONTIC APPLIANCE
 SEPERATING RUBBER BANDS
 RUBBER DAM SHEET

 SEPARATING WIRES:
 Thin pieces of brass wires are introduced gingival to the contact, then wrapped around
the contact area
 The two ends are twisted together to create separation not beyond 0.5mm.
 The twisted ends are bent into the buccal or lingual embrasure to prevent impingement
to upon the soft tissue.
 The wires are then tightened periodically to increase the separation.
 The maximum amount of separation will be equal to the thickness of the wire.

 SEPARATING RUBBER BANDS
 Used for orthodontic purposes can for achieving slow separation.
 It can be stretched and positioned interproximally between the teeth to produce slow
separation.
RUBBER DAM SHEET
 Heavy or extra heavy sheet is used
 Separation occurs due to the thickness of the tooth.
 The time taken for separation may range from 1-24hrs.

OVER SIZED TEMPORARY
CROWNS
Oversized in the mesiodistal
dimensions and resin added
periodically to the contact area to
increase the separation

• ORTHODONTIC APPLIANCE
Indicated only when extensive repositioning of tooth required
Most predictable and effective method

MATRICING
 DEFINITION
 PARTS
 CLASSIFICATION
 FUNCTIONS

 MATRIX is a device used during restorative procedures to hold the plastic
restorative material within the tooth while setting
 MATRICING is the procedure whereby a temporary wall is created opposite to
axial walls, surrounding areas of the tooth structures that were lost during the
cavity preparation.

PARTS OF MATRIX
 BAND:
A piece of metal or polymeric material used to support and give form to the restorative
material during its insertion and hardening.
 Materials used are:
Stainless steel
Cellulose acetate (cellophane)
Cellulose nitrate (celluloid)
Polyacetate (Mylar)
 Dimensions are:
Wide - 3/16th inch, 1/4th inch, 5/16th inch
Thickness – 0.001-0.002 inch

 RETAINER
This is a device by which the band can be maintained in its designated position
and shape,
The retainer may be
 Mechanical device
 Dental floss
 A metal ring or
 Impression compound

CLASSIFICATION
 DEPENDING ON THE TYPE OF BAND MATERIAL
1. Stainless steel
2. Copper band
3. Cellulose acetate
4. Polyacetate
 DEPENDING ON ITS PREPARATION
1. Custom made or anatomic matrix e.g. compound supported matrix
2. Mechanical matrix e.g. ivory no. 1, ivory no.8, tofflemire matrix

 DEPENDING ON THE MODE OF RETENTION
1. With retainer e.g. Tofflemire, Ivory no.1, Ivory no.8 matrices
2. Without retainer e.g. Automatrix
 DEPENDING ON THE CAVITY PREPARATATION
1. Class I cavity with buccal or lingual extension e.g. Double banded Tofflemire
2. Class II cavity e.g.
Single banded Tofflemire ,
Ivory no.1, and ivory no.8 matrices
Compound supported matrix
T-band matrix
Pre contoured sectional matrix
Automatrix

3. Class III cavity
 S shaped matrix
 Cellophane strips
 Mylar strips
4. Class IV cavity
 Cellophane strips
 Transparent celluloid crown forms
 Dead soft metal matrix strip
5. Class V cavity
 Window matrix
 Tin foil matrix
 Preformed transparent cervical matrix

FUNCTIONS
1. To confine the restorative material while it is hardening.
2. To establish optimal contacts and contours for the restoration .
3. To prevent gingival overhangs of the restorations.
4. To provide an acceptable surface texture for the restoration.

IVORY NO. 1
 This matrix consists of a stainless
steel band which encircles one
proximal surface of the tooth.
 This is attached to retainer via a
wedge shaped projection.
 An adjusting screw at the end of the
retainer adapts the band to the
proximal of the prepared tooth.

 As the adjusting screw is rotated
clockwise the wedge shaped
projections engage the tooth at
the embrasures of the unprepared
proximal surface.
INDICATIONS
 For restoring a unilateral class II
cavity especially when the contact
on the unprepared side is very
tight

Ivory no:8
 This matrix consists of a band that
encircles the entire crown of the
tooth.
 The circumference of the band can be
adjusted by the adjusting screw
present in the retainer.
INDICATIONS
For restoring class II cavities on one or
both proximal surfaces of a posterior
tooth.

Toffelemire retainer
 It is a versatile type of matrix
retainer. It is also referred to as
universal matrix .it was designed
by BR Toffelemire .
Advantages
 Its main advantage is that it can
be placed on the buccal or lingual
side of tooth as per requirement
 It is very stable when in position.

Tofflemire retainer
Indication
 It is ideally indicated for
MOD cavities
 Class II cavities
 Class I cavities with
buccal and lingual
extensions

Parts of Tofflemire retainer
 HEAD - This part
accommodate the matrix
band. It is U shaped with
two slots
 The head maybe straight
or angulated with
respected to rest of
retainer.

Accordingly there are two
types
1. Straight – Most frequently used
and is normally placed on the
buccal side of the tooth
2. Contra-angled – Used when the
retainer has to be placed on the
lingual surface of the tooth. The
angle of the handle allows it to
be place without the interference
of the anterior teeth.

Locking Vice
 This has a diagonal slot. The locking vice is positioned near the head, for
the placing the band in the retainer and positioning it around the tooth.
Pointed spindle
 This is used to adjust the distance between the head and locking vice
and also adjust the size of matrix band.

Small knurled nut
 Turning this nut clockwise tightens the pointed spindle against the band
and thus secure the band in the retainer. The reverse motion release the
pointed spindle from locking vise thus releasing the band from the
retainer.
Large knurled nut
 This is used to adjust the size of the loop of the matrix band either to
adapt or to loosen from the tooth.

Tofflemire Bands
 Available in 3 thicknesses – 0.0010, 0.0015, 0.0020 inches
 Thicker Bands – resist deformation during condensation
 Thin bands – helps to ensure a tight contact in class II restorations
 No.1 – universal band
 No 2 – Has two gingival projections for
application in teeth with deep gingival
margins
 No.3 – Similar to No.2 but is much narrower.

INDICATIONS
1. For class I cavities with buccal or lingual extension
2. For restoring class II cavities on one or both proximal surfaces of a
posterior tooth
ADVANTAGES
1. Ease of use
2. Produces good contact and contour for most amalgam restoration
3. Rigid and stable
DISADVANTAGES
1. Does not provide optimum contact & contour for posterior
composite restoration.
2. Not useful for extensive class II restoration.

Removal of the tofflemire
 To remove the tofflemire matrix first the smaller knurled nut is turned counter
clockwise to release the pointed spindle from the band.
 Then the larger knurled nut is turned counter clockwise to loosen the band
from the retainer.
 Now the retainer is freed from the band and gently removed.
 Next the band is disengaged from the uninvolved proximal side following
which it is removed from the restored proximal side by gently moving it.

 INDICATIONS
1. For restoring class II cavities involving one or both proximal surface.
2. For complex situations like pin-amalgam restoration
 ADVANTAGES
1. Highly rigid and stable
2. Provides good access and visibility for placing the restoration
3. Most efficient means of reproducing contact and contour
 DISADVANTAGES
1. Time consuming

 This is a Preformed T shaped stainless steel matrix band without a retainer.
 The Long arm of ‘T’ band is bent or curled to surround the tooth
circumferentially
 This overlaps the short horizontal arm of the ‘T’ which is bent over the
long arm and thus helps to retain the shape
 The band is adjusted according to the circumference of the tooth ,
stabilized by wedging & supported with low fusing compound

 INDICATIONS:
For class II cavities involving one or both proximal surfaces of a posterior tooth.
ADVANTAGES:
 Simple and inexpensive matrix system
 Rapid and easy to apply
DISADVANTAGES:
Flimsy in structure, not very stable.

PRECONTOURED MATRIX
 This consist of small, precontoured dead soft metal matrices ready for
application to the tooth.
 They are selected according to the tooth to be restored & wedged to
adapt the gingival contour
 Following this band is held in place by a flexible metal ring called BiTine
ring
 The metal ring holds the ends of the matrix band snugly against the facial
& lingual enamel
 E.g. Palodent BiTine matrix system , Composite –Tight Matrix system

INDICATIONS:
 For class II cavities involving one or both proximal surfaces of a posterior tooth.
 For both amalgam and composite restorations.
ADVANTAGES:
 Ease of application
 The metal ring also affords slight tooth separation.
 Provide better proximal contours for posterior composite restorations
DISADVANTAGES:
 Expensive
 Matrix band may become dented easily especially when the contact area of the adjacent
tooth is too close.

 COPPER BANDS of assorted sizes make excellent matrices
 These are cylindrical in shape & can be selected according to the diameter of the tooth
to be restored
 The bands are softened by heating to redness in a the flame & quenching in water
 After this the bands can be stretched & shaped with contouring pliers
COPPER BAND MATRIX

 The band is festooned in the cervical aspect with curved scissors so as to fit the
gingival contour of the tooth
 The occlusal height of the band is also adjusted
 With contouring pliers the band is contoured to reproduce the proper shape of
the contact area & the buccal & lingual contours
 Areas of the band in the contact area are thinned using green stone

 Following this the band is seated on the tooth & gingival border is crimped
inward to seal of the margins
 Wedges are used to stabilize the bands
 Compound may be applied on the external portions of the band to further
stabilize the matrix
 Using a heated ball burnisher from inside the cavity to the band , contours can
be improved
 After condensation & carving of amalgam , band is left in place. It is sectioned
& removed at the next appointment.

INDICATIONS:
For badly broken down teeth especially those receiving pin-amalgam restorations.
For complex situation like class II cavities with large buccal or lingual extensions.
ADVANTAGES:
Provide excellent contour
DISADVANTAGES:
Time consuming

AUTOMATRIX
Auto matrix band
Automate II tightening device
Shielded nippers

AUTOMATRIX
 The Automatrix is a Retainer less matrix system. It has following components
1. Automatrix bands : Available in three widths
1. 3/16th inch
2. 1/4th inch
3. 5/16th inch
2. Automate II tightening device : This is used to adjust the loop of the band
according to the circumference of the tooth to be restored
3. Shielded nippers: This device is used to cut the band

PLACEMENT OF AUTOMATRIX
Selection of band
Circumferential adjustment and burnishing
Tightening using Automate II tightening device
Wedge Placement
Softening & Adaptation
To Remove: use shielded nippers to cut the autolock loop

• For Complex Amalgam Restorations.Indications
• Convenient to use.
• Improved visibility.
• Rapid Application.
Advantages
• Cannot develop proper contacts & contours.
• Expensive.
• Bands are flat and difficult to burnish.
Disadvantages

S SHAPED MATRIX
 For class III,class II and with facial/lingual extensions of class V.
 Matrix band of 0.001”-0.002” is used.
 Mirror handle is used to produce the s-shape in the strip.
 Strip is contoured in its middle part with contouring pliers
to create desired form for the restoration.

CLEAR PLASTIC MATRIX
 Employed as matrices for tooth colored restorations.
 These may be cellophane or Mylar strips, which may be contoured using
operating pliers.
 The convex contoured area of the matrix band is positioned facing the
proximal surface of the tooth to be restored.
 The band should extend at least 1mm beyond the gingival & incisal
margins of cavity preparation

• For small & Large class iii & iv tooth
coloured restorations
Indications
• Easy to use
• InexpensiveAdvantages

TRANSPARENT PLASTIC CROWN FORM MATRIX
 These are commercially available transparent plastic crown forms
 They are available in various sizes & contours for anterior teeth
 A suitable crown form can be selected for the prepared tooth & trimmed
to fit 1mm past the prepared margins
 The bulk of the composite resin is loaded into the crown form
 This is then positioned over the tooth & light curing is done
 Thus the contours of the tooth can be shaped easily
 After curing the crown form can be slit with a bur & removed

Easy to use
Good contours can
be established
Placement is time
consuming
Expensive
ADVANTAGES
DISADVANTAGES

WINDOW MATRIX
 This is a modification of the tofflemire
matrix
 It is used for class v amalgam
restoration
 The contra- angled tofflemire retainer is
applied on the lingual side of the tooth
 A window is cut in the band slightly
smaller than the outline of the cavity
 wedges are placed interproximally to
stabilize the band
 Following this amalgam can be
condensed through the window &
contoured using carvers
 The matrix is removed once the
amalgam is hardened

TIN FOIL MATRIX
 This matrix is used for class V restorations for conventional glass ionomer
cements.
 Tin foil may be preshaped and cut according to the gingival third of the buccal
and lingual surface of the teeth to be restored.
 The band is adjusted so that it extends 1-2mm circumferentially beyond the cavity
margins.
 This can be adapted on the cavity by means of a tweezer after placing the glass
ionomer cement.
 Once the restoration sets the tin foil matrix can be peeled away

INDICATIONS
• For class v with
conventional GIC
ADVANTAGES
• Simple and easy to
use
• Provides optimum
contour
DISADVANTAGES
• Not useful for class
V composite resin or
RMGIC restorations

PREFORMED TRANSPARENT CERVICAL MATRIX
 Transparent plastic cervical matrices that
are commercially available in various
contours for use in anterior and posterior
teeth.
 They are designed for use with light
cured composite resin or glass ionomer
restorations.
 A handle or tweezer can hold the matrix
in place while the restoration is
hardening

ACHIEVING CONTACTS & CONTOURS WHILE USING
DENTAL COMPOSITES

Key aspects for achieving c/c with composite
material
 Proximal contour
 Location of the contact area
 Contact tightness
 Gingival adaptation

PROXIMAL CONTOUR
 This includes occluso gingival and buccolingual contour of the composite
restoration on the proximal aspect
 This should be adequate to maintain contact with the adjacent tooth and it should
not be overly convex,concave or flat

LOCATION OF THE CONTACT AREA
 Recreation of the contact area in its ideal location will help to develop the
ideal embrasure form thereby preserving the health of the gingival col and
enabling food deflection during mastication.
 It is usually located in the upper middle third of the crown of most teeth of
both proximal ends of the tooth and beneath the marginal ridges

CONTACT TIGHTNESS
 Once the restoration is in place the contacting teeth must be in close
approximation.The contact must be neither open or too tight.This can be
checked by using dental floss

GINGIVAL ADAPTATION
 This is very important in long term success of the restoration as
microleakage at this critical site is a leading cause for secondary caries

VARIOUS CLINICAL TECHNIQUES
 Initially clinicians continued to use circumferential matrices in a tofflemire retainer
along with a wooden wedge. However this resulted in
 Circumferential band created a flat interproximal contour
 During band tightening they tempted to flatten out buccolingually resulting in
open contacts
 Contact area shifted more occlusally closer to marginal ridge. the fracture of the
restoration,creation of a large gingival embrasure associated food impaction and
gingival defects.

 Hence circumferential transparent matrices were used along with light
reflective wedges the rationale being light polymerization of the
composite would be more effective with this combination.
 However clear matrices were not flexible enough to adapt properly in the
posterior region and wedge placement was also difficult creating
overhangs

 All these problems led to the development of
various innovate methods
 Contact forming instruments
 Ceramic inserts
 Light tips

Contact forming instruments
 These are special instruments used to create proper contact and contour.They push
the matrix towards the contact area towards light curing.eg Contact Pro,
 Optra contact(Ivoclar,vivadent)
Contact Pro,
Optra contact

The Contact Pro is inserted into unpolymerized composite
resin and wedged against the neighboring. By doing this it is
able to establish a definite interproximal contact

Contact former(American eagle instrument)
 This instrument is pushed into the composite and pressed against the
contact area during light curing and additional increments are added.
 However the contacts produced were closer to marginal ridge while the
proximal contour was Lacking.

Ceramic insert
 Prefabricated ceramic inserts like Beta quartz,are available in various
sizes.
 These inserts displaces most of the composite of the restorations.
 These instrument provides excellent gingival marginal adaptation and
creation of tight contacts.
 The major problem associated with ceramics insert is that it created an
unnatural proximal contour.

Light tips
 It has been reported that compared to class II amalgams,class II
composites leak significantly more at the gingival margins.

• The use of light tips were recommended
• They help to focus the light closer to the gingival margin
thereby improving the curing and adaptation of the composite
material
Problems attributed with the tips
• Tips are prone to breakage
• Contact is not formed at the right location
• May be large for Conservative preparations

Evolution of new techniques
CONTACT RINGS & SECTIONAL MATRIX SYSTEM
 The First real solution to posterior composite contact came with the
introduction of sectional matrix & contact rings
 Introduced by Meyer in1985

BASIC PRINCIPLE OF CONTACT RINGS
 These rings work by providing slight separation of the contacting teeth.
 When the ring is expanded and its tines are placed over the contact area
between the teeth,its spring action applies equal and opposite forces
against the teeth thus providing optimum separation

FIRST GENERATION SYSTEMS
• First system available
• Rings have rectangular tines which are parallel
• Easy to place but lack retentive features
PALODENT BITINE I &II
• Rectangular tines converging & retentive
• Reverse ring available for MOD preparation
CONTACT RINGS
• 2 Separate rings for premolar & molar teeth
• Rings have converging tines with retentive balls
at the end
• But the contacts produced are not tight
COMPOSI- TIGHT
MATRIX

PALODENT BITINE RING
COMPOSI TIGHT MATRIX

EASE OF USE & GOOD VISIBILTY
ANATOMIC CONTOUR OF BAND ENSURES
OPTIMAL CONTACT AREAS & EMBRASSURES
NO NEED FOR PREWEDGING
GINGIVAL ADAPTATION OF THE RESTORATION IS
GOOD
CONTACT DIMENSIONS ARE ADEQUATE
RING COLLAPSE OR DISPLACEMENT IN CASE OF
WIDE PROXIMAL BOX
PLACING 1 RING OVER OTHER IN CASE OF MOD
RESTORATION IS A PROBLEM
REPEATED USAGE LEADS TO LOSE OF
SPRINGINESS
BENEFITS V/S PROBLEMS OF EARLY
CONTACT RINGS

SECOND GENERATION SYSTEM
COMPOSI-TIGHT 3D
SOFT FACE RING
• 2 STYLES OF RINGS
• THE TINES OF THE RING ARE
COVERED WITH SILICONE
• SOFT FACE IS SHAPED TO MIMIC
THE INTERPROXIMAL
IT ADAPTS THE BAND PRECISELY
TO THE TOOTH CONTOUR
V3 RINGS
• MOST ADVANCED RING SYSTEM
CURRENTLY AVAILABLE
• DEVELOPED BY DR SIMON
MCDONALD IN 2008
• 2 TYPES OF RINGS FOR BICUSPID
AND MOLAR
• PRECONTOURED MATRIX BANDS

TWO MAJOR INNOVATIONS
 Ring is fully made of Nickel-Titanium which imparts more springiness and
longevity.
 V-shaped plastic tines to accommodate wedge and having extra width to
contact more tooth structure providing good contour

Hazards of faulty reproduction of teeth in
restorations
A. Contact size.
B. Contact configuration.
C. Contour.
D. Marginal ridge

I Contact size :
I. Creating a contact area i.e.
too broad, bucco-lingually
or occluso-gingivally.
II. Creating a contact area i.e.
too narrow, bucco-lingually
or occluso-gingivally.
III. Open (loose) contact.

IV. A contact area placed too
occlusally.
V. A contact area placed too
buccally or lingually.
VI. A contact area placed
too gingivally.

B. Contact configuration
1. Creating a contact area i.e. flat (deficient convexity).
2. Creating a contact with excessive convexity.
3. A concave contact area in a restoration.
C. Contour -
1. Facial and lingual convexities.
2. Facial and lingual concavities.

Marginal ridges
The following examples will illustrate the consequences
incurred by the creation of faulty marginal ridge.
1. Absence of a marginal ridge in the restoration.
2. Marginal ridge with an exaggerated occlusal embrasure.

Adjacent marginal ridge not compatible in height.
4. Marginal ridge with no occlusal embrasure.
5. A marginal ridge with no triangular fossa.

CONCLUSION
 Clinicians should have an adequate knowledge about the anatomy and
functional aspects of contacts and contour so as to reproduce the tooth
structure using proper restorative materials. Availability of different matrix
systems helps us to reproduce the normal anatomy and contact between the
teeth.
 An adequate understanding of relationship between periodontal tissues and
restorative dentistry of is paramount importance to ensure adequate form,
function, aesthetics and comfort of the dentition

REFERENCES
• STURDVENTS ARTS AND SCIENCES OPERATIVE DENTISTRY
• TEXTBOOK OF OPERATIVE DENTISTRY VIMAL SIKRI
• RAGHU AND RAMYA SREENIVASAN,JCD 2015
• MARZOUK’S OPERATIVE DENTISTRY
• TRIODENT WEBSITE
• PALODENT WEBSITE

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