CONTACTS AND CONTOURS IN CONSERVATIVE DENTISTRY / rotary endodontic courses by indian dental academy

CONTACTS AND CONTOURS IN
CONSERVATIVE DENTISTRY

INDIAN DENTAL ACADEMY
Leader in Continuing Dental Education
www.indiandentalacademy.com

 Wheeler, R.C 1961,Goldman 1969, Dunmett
C.O 1966, stressed the relationship of tooth
contours to the surrounding gingivae.

 Sanjana et al 1956 pointed out the missing or
inadequate contact points and its ill effects on
the periodontal health.

 Picton 1966 has shown that teeth in good
contact have a significant periodontal status
than spaced teeth with poor contacts.

www.indiandentalacademy.c

 Brauer JC, Richard RC 1964 illustrated the
serious complication arising from improper
location and degree of facial and lingual
convexities.
 Mortan L. Perel 1971, studied the effect of
over contouring and under contouring on
surrounding marginal gingiva. He concluded
that, under contouring of various types did not
produce any circumscribed changes in
gingiva. Over contouring - inflammatory and
hyperplastic changes in marginal gingiva.


 Ralph.A. et al in their study in 1973, stated
that greater the degree of facial and lingual
bulge the more plaque retained in the cervical
region, the flatter the contour the less the
plaque retained.
 Ramfjord S.P 1974, in his study concluded
that under contoured crowns with flat cervical
surfaces may lead to a thickening of gingival
margin.
 James G . Burch 1971 suggested 10 rules for
developing crown contours in restorations
and factors that influence tissue health
around restorations.


WHAT IS CONTACT ?

 Proximalcontact area is the term used
to denote the area of proximal height of
contour at the mesial and distal
surfaces of a tooth that touches its
adjacent tooth in the same arch.


Formation of contact area:

 When teeth erupt, initially a contact
point.
 This becomes an area due to wear of
one proximal surface against another
during physiological tooth movements.


Functions of interproximal contact areas:

1. To maintain a stable dental arch.

2.The prevention of food impaction in
inter dental area.


According to their shape

 1. Tapering teeth
 2. square type
 3. ovoid type


Contact Tapering type [wide crowns and
narrow apices]

1. Between incisors Contact starts at incisal ridge incisally
Little towards the labial , labio- lingually

2.Canines Mesial contact at the incisal ridge
Distal contact near the middle
Very angular

3.Bicuspids Buccal periphery almost at buccal
axial angle of the tooth
Occlusal periphery at the junction of
occlusal and middle third of the tooth
Contact is deviated buccally

4.Molars mesial contact Buccal periphery almost at the buccal
axial angle of the tooth
O-periphery, at the junction of occlusal
and middle third of the crown
5.Molar distal contact Buccal
periphery at the middle third
O-Periphery, at the middle third

www.indiandentalacademy.c firstdistal cusps
Distal contact of
due to the position of
molar is variable

Contact Square type teeth[boxed]

Starts at incisal ridge incisally and in
1. Between incisors line with it labio lingually

Close to incisal ridge incisally
2.Canines In line with them labio-lingually

Buccal periphery more towards buccal
3.Bicuspids axial angle
Occlusal periphery at occlusal third

4.Molars mesial contact Same as premolar
Extension lingually stops in the middle
third

5.Molar distal contact More lingually deviated than mesial but
not to the extent of tapering teeth

Ovoid type[transitional]
Contact

1. Between incisors Slightly lingual to the incisal ridge,
labio-lingually
Mesial contact starts at ¼ of the crown
inciso-gigivally
Distal contact starts 1/3 to ½ of the
crown inciso-gingivally

2.Canines Same as square type

3.Bicuspids  Convexity of MR carries contact s
almost to the middle third of the crown
height[op]
 Buccal periphery at the junction of
buccal and middle third

4.Molars mesial contact Same as bicuspids

5.Molar distal contact Buccal
periphery in line with the
central groove in occlusal surface.

Facial and lingual contours:

 In vertical direction all tooth crowns will
exhibit some convex curvatures
occlusal to the cervical line - cervical
ridge.
 on a completely erupted permanent
teeth should not extend more than 1mm
beyond the cervical line.
 The average curvature is about 0.5mm
or less.

 Facial and lingual contours protect the free
gingival margin from the traumatic effects of
mastication.
 Mandibular posterior teeth will have a
lingual curvature of approximately 1mm which
is mainly caused by the lingual inclination of
these teeth.
 Mandibular anterior teeth will have less
curvature on the crown above the cervical line
than any other teeth usually less than 0.5mm.

 The canines show a little more curvature than
the central and lateral incisors.


 In maxillary anterior teeth -incisal one half to
two thirds of the lingual surface displays
some concavities - act as anterior
determinants for mandibular movements.
 In posterior teeth there will be mesio distal
convexity, corresponding to each cusp in
anatomical crown position of the tooth.
 This convexity on the facial and lingual areas
decreases in magnitude as it approaches the
cemento enamel junction.
 At CEJ or slightly occlusal to it , the facial or
lingual surfaces will flatten or become
concave.

Interproximal spaces:

 Triangular shaped spaces normally
filled by gingival tissue.
 The base of the triangle is alveolar
process , the sides of the triangle are
proximal surface of the contacting
teeth; and apex is contact area.


Embrasures

 When teeth are in proximal contact, the
spaces that widen out from contact are
known as embrasures.
 Each inter dental space has four
embrasures

 1. facial
 2. lingual
 3. occlusal/incisal
 4. gingival

 The embrasure form serves two purposes

 1. Makes spill way for the escape of the
food during mastication.

 2. prevents food from being forced
through the contact area.


Embrasures in tapering teeth;

1. wide variations are seen
 2. incisal and labial are negligible
 3. gingival and lingual embrasures between
anterior teeth are the widest and longest in
the mouth
 4. buccal embrasures are small
 5. lingual embrasures are long with medium
width
 6. gingival eembrasures between posterior
teeth are broad and long.


Embrasures in square type teeth:

 1. Incisal, occlusal , lingual and
buccal embrasures are nil
 2. Gingival embrasures are almost
not noticeable ; if found they are very
narrow and flat.
 3. Lingual embrasures are very
narrow and long.


Embrasures in ovoid type teeth:

 1. labial, buccal, incisal, and occlusal
embrasures are wider and deeper than
the others

 2. gingival and lingual are short and
broad.


 Marginal ridge:

 Marginal ridges are the rounded
elevations of enamel that form the mesial and
distal margins of the occlusal surfaces of the
posterior teeth and lingual surface of the
anterior teeth.

 It is imperative to have marginal ridge of
proper dimensions that is compatible to the
dimension of occlusal cuspal anatomy,
creating a pronounced adjacent triangular
fossa and producing an adjacent occlusal
embrasure

A marginal ridge should always be
formed in two planes bucco-lingually,
meeting at a very obtuse angle.

 This feature is essential when an
opposing functional cusp occludes with
the marginal ridge.


A marginal ridge with these
specifications is essential for

 The balance of the teeth in the arch,
 prevent food impaction ,
 To protect periodontium ,
 Prevent recurrent and contact decay
 For helping in efficient mastication.


 Thisdiagram illustrates how a proper
marginal ridge will perform these
functions


 Proceduresfor the formulation of
proper contacts and contours


Intra oral procedures

Two operative procedures must
accompany or precede the
restorative procedure:

1. Teeth movement
2. Matricing


Tooth movement:

 It is the act of either separating the
involved teeth from each other, bringing
them closer to each other , or changing
their spatial position in one or more
dimensions.


Objectives of tooth movement
 1. To bring drifted , tilted or rotated teeth to
their indicated physiologic position
 2. To close space between the teeth not
amendable to closure by the contemplated
restoration.
 3. To move teeth to another location so that
when restored they will be in a position most
physiologically accepted by the periodontium.
 4. To move teeth occlusally or apically in
order to make them restorable.

 5. To move teeth from non functional or
traumatically functional location to a
physiologically functional one.
 6. To move teeth to position so that they will
be in a most esthetically pleasing situation when
restored.
 7. To create a space sufficient for the
thickness of the matrix band interproximally.


Rapid or immediate tooth movement:

 This is mechanical type of separation

 Creates either proximal separation at
the point of separators introduction and
improved closeness opposite to the point of
separators introduction.


 Indications:
Indications
 1. As preparatory to slow tooth movement
 2. To maintain the space gained by the slow
tooth movement.

should not exceed the thickness of the involved
tooth periodontal ligament space that is 0.2 -
0.5mm.


Rapid or immediate tooth movement can
be done by one of the following
methods:

I. wedge method:
separation -by the insertion of a pointed
wedge shaped device between the teeth .
The more the wedge moves facially or
lingually the greater will be the separation.


Types of separators:

2. Elliots separator: .
 Indicated for short
duration separation
that does not
necessitate
stabilization.

 It is useful in
examining proximal
surfaces or in final
polishing of restored
Contacts

Wooden or plastic wedges:
wedges

 These are triangular shaped wedges , usually
made of medicated wood or synthetic resin .
 In cross section - the base of the triangle in
contact with the inter dental papillae.
 The two sides -coincide with corresponding
gingival embrasure.
 The apex - coincide with the gingival start of
the contact area.


TRACTION METHOD:

 This is done with mechanical devices
which engages the proximal surface
of the teeth to be separated by means
of holding arms.


Examples of traction
method include:

A. non- interfering true
separator:
 Indicated when continuous
stabilized separation is
required.
advantages
 Separation can be
increased or decreased
after stabilization.
 The device is non
interfering.


B. Ferrier double bow
separator:
 separation can be
stabilized through out
the operation.
Advantage
 separation is shared
by contacting teeth
not at the expense of
one tooth.


SLOW OR DELAYED TOOTH
MOVEMENT:

INDICATONS :
 When teeth have drifted or tilted
considerably, rapid movement of the teeth
to the proper position will endanger the
periodontal ligaments.
 slow tooth movement over period of
weeks, will allow the proper repositioning
of the teeth in a physiologic manner.


Methods:
Separating wires:
 Thin pieces of wire are introduced
gingival to the contact then wrapped
around contact area.
 The two ends are twisted together to
create separation not to exceed 0.5mm.
 The twisted ends are then bent in to the
buccal or lingual embrasure to prevent
impingement up on soft tissue or
interference with the food flow.

 The wires are then tightened
periodically to increase separation.

 This is very effective method of
slow tooth movement, although
the maximum amount of
separation will be equivalent to the
thickness of wire.


Oversized temporaries:
temporaries
 Resin temporaries that are over sized
mesio-distally may achieve slow
separation .
 Resin is added to the contact areas
periodically , to increase the amount of
separation, which will not exceed
0.5mm per visit.


Orthodontic appliances:

 For tooth movement of any magnitude,
fixed orthodontic appliances are the
most effective and predictable method
available.
 Comparable end results may be
achieved by removable orthodontic
appliances, but they require longer
treatment.


 After repositioning of the tooth by
delayed tooth movement
techniques, it is necessary to use
one or more of the immediate tooth
movement techniques, just before
or during the restoration fabrication,
to create space and to compensate
for the thickness of the band
material.


MATRICING:
MATRICING

 Matricing is a procedure where a
temporary wall is created opposite to
the axial walls, surrounding areas of
tooth structure that were lost during
preparation.


OBJECTIVES:
The matrix should:
1.      Displace the gingiva and rubber
dam away from the cavity margin .
 2.      Assure dryness and prevent
contamination
 3.      Provide shape for the restoration
during setting of the restorative material.
 4.      Restoration of correct proximal
contact relation ship
 5.      Establishment of proper anatomic
contour


classification of matrices:

 Metal: firm , used for amalgam
 Mylar: easily moldable and light cure
through
 Plastic: rigid can light cure through
used in class V cavities


universal matrix :
 Designed by B.R
Tofflemire .
 Ideally indicated when 3
surfaces of posterior
teeth are prepared.
 Commonly used for 2
surface class II
restoration.
 There are 2 types of
Tofflemire straight and
contra angle.

 Matrix bands of various occluso gingival
widths are available.
 The uncontoured bands are available in
2 thicknesses, 0.05mm and 0.0015mm.

 Uncontouredband must be burnished
before assembling the band and
retainer


 theband positioned 1mm apical to the
gingival margin and 1-2 mm above the
adjacent marginal ridge.

 substantialdifference between the
heights of inter proximal gingiva on
mesial and distal sides, matrix band
should be trimmed so that it is narrower
on the side where the inter proximal
gingival is more occlusally located.


Ivory no.1:
 The band encircles
posterior proximal
surface ,indicated in
unilateral class II cavities.

Ivory matrix no 8;
 The band encircles the
entire crown of the tooth,
indicated for bilateral
class II cavities.


Black’s matrices;
 Recommended for the
majority of small and medium
size cavities
Procedure;
 Cut a metallic band so that it
will extend only slightly over
the buccal and lingual
extremities of the cavity
preparation.
 To prevent a wrap around,
holding ligature from slipping
of the band and band sliding
gingivally, the corners of the
gingival ends are turned up to
hold the ligature.

 Black’s matrix with a
gingival extension

 Extension is created in the
occluso-gingival width of the
band to cover the gingival
margin.
 The ligature should be
securely tied with a surgical
knot on the side, after
wrapping it around the tooth.
 A wedge should be carefully
adjusted to produce and
maintain the proper
separation and to hold the
band tightly.

Soldered band or seamless copper band
matrix;

 These are indicated for badly broken down
teeth especially those receiving pin-retained
amalgam restorations, with large lingual and
buccal extensions.
 Assorted copper bands -sizes from 1 – 20.
 size no. 1 is 4mm and size no. 20 is 12 mm.
 Thickness - 0.15mm.


Procedure;
 A stainless steel band is cut
according to the measured diameter
of the crown of the tooth.
 Then two ends are soldered
together or a seamless copper band
is selected.
 Either band could be heated in a
flame until it blows red.
 Then quenched in alcohol, thus
softening the band for easier
handling.


 With curved scissors, festoon the band
so its gingival periphery corresponds to
the gingival curvature and CEJ.
 With contouring pliers contour the band
to produce proper shape in contact area
as well as buccal and lingual contours
to be restored.


 Band in the contact area are reduced to
paper thinness using a coarse sand
paper disc.
 Band seated on the tooth and tightened
at the cervical end by pinching up a
“tuck” using a flat bladed plier.
 To stabilize the band and prevent
cervical flashes of amalgam, wedges
are placed.
 The external portion of the matrix and
the wedges are covered with compound
to further stabilize the matrix.
 A wire ‘staple’ is inserted facio-lingually
in the compound to further stabilize it.


The anatomical matrix:
 This is the most efficient means of
reproducing contact and contour.

Procedure:
 A piece of 0.001-0.002 stainless
steel matrix band 1/8” in width is
drawn between the handle of a pair
of festooning scissors the matrix
band is then cut to the proper length.
It should extend well beyond the
cavity margins.


 Wedge is selected and then placed.
 small cones of compound are warmed
and then forced in to the buccal and
lingual embrasures.
 The pressure is maintained until
compound has flowed evenly over the
entire buccal and lingual surfaces of the
adjacent tooth .
 The staple is heated and then forced in to
the compound in the buccal and lingual
embrasures.


 Automatrix [ Roll-in band matrix ]
 This is a retainer less matrix system
with 4 types of bands that are designed
to fit all teeth, regardless of
circumference. The band vary in height
from 4.7mm, 6.35mm, 7.9mm and are
supplied in two thicknesses 0.038mm
and 0.5mm


Advantages:
 1.      convenience
 2.      improved visibility because of
absence of a retainer
 3.      ability to place auto lock loop on
the facial or lingual surface of the tooth
 4.      decrease time for application
application as compared to copper
band matrix



 disadvantages;
 1. theband is flat and difficult to
burnish and is some times unstable
even when wedges are in place.
 2. development of proper proximal
contour and contacts can be difficult
with a auto matrix


Procedure:

 Band should be slightly larger than the
circumference of the tooth.
 The band is tightened with a
device[automate] which is inserted in
the coil.
 The autolock loop secures the band
and the system is wedged.
 Compound may be applied to stabilize
the band .
 After insertion of amalgam the
autolock loop is cut with shielded
cutters and carefully removed.


T – Shaped Matrix:

 These are pre made T – shaped brass
or stainless steel matrix bands.
 The longer arm of the matrix is bent to
encompass the tooth circumferentially
and to overlap the short horizontal arm
of T.
 This section is then bent over the long
arm, loosely holding it in place.


S-Shaped matrix band:
 Ideal for class III , is also
used in class II.
Procedure.
Procedure
 Matrix band of 0.001-
0.002” thick band is used .
 Mirror handle is used to
produce S-shape in the
strip.
 With the contouring pliers
the strip is contoured in its
middle part to create
desired from for the
restoration.

Mylar strip:
 Class III direct composite restorations with
normal alignment.
Procedure:
 mylar strip burnished with the handle of the
tweezer to produce ‘belly’.
 This will produce normal contour of the
teeth.
 Length of the strip -sufficient to cover the
labial and lingual surfaces of the tooth.
 Wedge is trimmed and introduced from the
opposite side of the access.


Matrix for class III preparations in teeth with
irregular alignment:

 Suitable plastic strip contoured and
adapted.
 For labial approach compound impression is
taken of the lingual surface.
 The compound is allowed to over lap the
adjoining teeth. Excess trimmed off to
produce a flat surface.
 The strip is placed in position, compound
impression is warmed and than placed in
position assuring perfect adaptation of the
matrix to the cavity on the lingual surface.

Matrix for small
preparations in
contact with each
other:

 An appropriate plastic
strip is folded with one
end slightly longer than
the other to facilitate their
separation after insertion
of strip between the teeth.

 The loop is flattened and
creased with a finger,
making a ‘T’ shape, and
trimmed.


 The matrix is than placed between the teeth.
For labial approach the strip held over the
lingual surface.
 After insertion of material each wing of the
strip is folded towards the setting material
and held with the thumb of the left hand.


Matrices for class IV
preparations for
direct tooth colored
materials.

 A suitable plastic strip is
folded at an angle to L-
Shape, than sealed with
a plastic cement or any
adhesive that does not
react with tooth colored
material.


 One side of the strip is cut so that it is as wide
as the length of the tooth .
 the other side is cut so that it is as the wide of
the tooth


 The strip with a wedge in place is adapted to
the tooth.
 The angle formed by the fold of the strip
approximates the normal corner of the tooth.
 The cavity is filled with slight excess , and
one end of the strip is brought across the
proximal surface of the filled tooth.
 Then this is completed the other end of the
strip is folded over the incisal edge.
 The matrix is held with the thumb of the left
hand.


Aluminium foil incisal corner
matrix:

 These are ‘stock’ metallic matrices
shaped according to the proximo-incisal
corner and surface of the anterior teeth.

 Can not be light cured.


Procedure:
 A corner matrix closest in
size and shape of the tooth
is selected.
 Trimmed gingivally, so that it
coincides with the gingival
architecture and covers the
gingival margin of the
preparation.
 shape it with thumb and first
finger until it fits the mesio-
distal and labio-lingual
dimensions of the tooth.


 Loosely place the wedge, allowing for the
matrix band thickness.
 Partially fill the preparation and corner of
the matrix, preferably after venting the
corner.
 Apply partially filled matrix over the
partially filled tooth preparation.
 Tighten the wedge and wipe of excess
material.


Transparent crown form matrices:

 These are ‘stock’ plastic crowns
which can be adapted to the tooth
anatomy.
 This type can be used for light cured
resin material.


Anatomic matrix:
 Study model for
affected teeth together
with at least one intact
adjacent tooth on each
side is made.
 The defective area on
the study model is
restored with a fairly
heat resistant material [
plaster, acrylic resin,
blocking compound,
plasticine etc..] or
appropriate
configuration.

 A plastic template is
made for the restored
tooth on the model
using the combination
of heat[ to
thermoplastically soften
the template material]
and suction [vaccum]
consequently to draw
the moldable material
on to the study model.


 The template is trimmed.
 It should seat on atleast one
unprepared tooth on each side.
 matrix should be vented by perforating
the corners.
 The restorative material is inserted in to
the preparation,and matrix inserted
over the prepared and partially filled
tooth, ready for curing.


Matrices for class V amalgam
restoration:
Matrices are indicated in the following
situation
 1.      sub gingival cavities
 2.      lingual cavities –especially in lower
molars
 3.      cavities extending in to proximal surfaces
 4.       large cavities where prominence is
required for retention of dentures .


Window matrix :

 Tofflemire matrix or copper band
matrix
 The contra angle retainer is
applied at the side of the tooth
that does not have the
preparation.
 A window is cut slightly smaller
than the out line of the cavity.
 Wedges are placed mesially and
distally to stabilize the band.


S- Shaped matrix:

 Indicated for proximal extension of class V
preparation.


Other options in lieu of matrices in
extremely wide class V Cavities:
 The cavity is prepared in two stages – a
mesial half is prepared and filled with
amalgam.
 After the amalgam hardens , the distal half is
prepared and restored.
 If there are sufficient mesial and distal walls ,
condense the mesial one third of the
amalgam mesio-axially and the distal one
third disto –axially, allow to partially harden,
then condense the middle third axially with a
flat bladed instrument.


Matrices fro class V preparations for direct
tooth colored restorations:
Anatomic matrix for non light cured ,
direct tooth coloured materials:
 cavity is filled with gutta percha or inlay wax
and trimmed to contour.
 The wax and the tooth are coated with cocoa
butter or mylar strip -compound impression is
taken.
 Adjacent surfaces are to be included in the
impression.
 After the compound has cooled , it is
removed and the wax is removed from the
cavity.

 A mix of restorative material is made and
placed in to the cavity, and the compound
matrix is placed in to the position and
securely in position until the material is set


Aluminium or copper collar for non-light
cured direct tooth coloured restorations:

 Aluminium or copper bands are pre shaped.
 Adjusted so that the band will cover 1-2mm
of the tooth structure circumferential to the
cavity margins
 Mounted on the tip of the softened stick of
compound , which is used as handle.
 Fill the cavity with restorative material and
apply the adjusted collar to the tooth .


Anatomic matrix for light cured and non
light cured , direct tooth coloured
materials:

 Study models for the defected tooth
are taken same as for class IV and
matrix is fabricated.


Didner wax contouring instrument for
class V cavities:

 When a Didner instrument is to be used , a
cup that is suitable for the situation is first
selected from the available points.
 This cup is secured in the handle at the
proper angle as determined by its application
to the tooth and lubricated .


Wedges:
wedges perform the following functions
 1. Assure close adaptability of the band
 2. Occupy the space designed to be the
gingival embrasure.
 3. Define the gingival extent of the
contact area as well as facial and
lingual embrasures.


 1. createsome separation to
compensate for the thickness of the
matrix band.
 2. establish atraumatic retraction of the
rubber dam and gingiva .
 3. assure immobilization of the matrix
band.
 4. protect the interproximal gingiva from
unexpected trauma.


 Although wedges are supplied in different
sizes, because of variations in configurations
of gingival embrasures wedges should be
trimmed to exactly fit these embrasures.
 The length of the wedge should be ½ inch.
 Wedges are made of wood and plastic
 Wooden Wedges made from soft spine and
hard oak. The pine wedge is compressible on
insertion, the oak wedge is not. The
advantage of wooden wedges are they can
be easily cut and trimmed and they absorb
water intra orally. This causes them to swell ,
improving their inter proximal adaptation.



 The advantage of resin wedges is that they
can be plastically molded and bent to
correspond with the configuration of the
interdental col.

 Wedge should be positioned as near to the
gingival margin as possible with out being
occlusal to it. If a wedge is significantly apical
to the gingival margin, a second wedge may
be placed on top of the first wedge . this type
of wedging is particularly useful fro patients
whose inter proximal tissue level has
receded.


 WedgeWands:
 anatomically-contoured, disposable, plastic
wedges attached to plastic handles (wands)
-placed without using an instrument.
 The angle of the wedges can be adjusted by
bending the neck area where the wedge
meets the wand, allowing their placement.
 wedges have a curved underside and
contoured sides that leave room for the
interproximal papilla and enable the wedges
to more intimately adapt to the interproximal
contours.


 wedges also have a slightly upturned tip that
prevents inadvertently piercing the soft
tissues and rubber dam during placement.
 Following placement, the handle is twisted to
separate it from the wedge.
 . The wedges come in three color-coded
sizes (small, medium, large) .


ADVANTAGES:
 Disposable wand allows placement without a
forcep
 Contoured shape for more intimate
interproximal adaptation
 Available in three sizes
DISADVANTAGES:
 Wand difficult to remove after wedge
placement
 Expensive


Double wedging:
 permited when proximal
box is wide faciolingually.
 refers to using two
wedges : one from the
lingual embrasure and
one from facial
embrasure
 should be used only if the
middle two third of the
proximal margins can be
adequately wedged.


 Because the facial and lingual corners are
accessible to carving,proper wedging is
important to prevent gingival excess of
amalgam in the middle two third of the
proximal box.


 Passive Wedge
Quintessence Int 1996; 27:243-248.
 This wedge is less traumatizing to the soft
tissue than conventional wooden wedges,
hence it will be less damaging to the papillae,
causing less bleeding and allowing better fluid
control. This new technique will may allow
you to perform higher quality dentistry with
your adhesive procedures


Procedure:
 1. Push matrix with one finger in the incisogingival
direction and place a small cotton pellet into the
interproximal space between the matrix and the
adjacent tooth.
 2.Soak the pellet with a disposable brush filled with
cyanoacrylate.
 3.The matrix is placed in its proper position.
 4.Maintain the matrix in its position, while air-water
spray soaks the cotton pellet.
 5.This will harden the pellet immediately, in the
exact shape of the interproximal space without
either compression or traction on the soft tissue.


Wedge- wedging:
 Occasionally , a
concavity may be
present on the proximal
surface that is apparent
in the gingival margin.

 This may occur on the
surface with a fluted
root, such as the mesial
surface of maxillary first
premolars.


 A gingival margin located in this area may be
concave.

 To wedge a matrix band tightly against such
a margin, a second pointed wedge can be
inserted between the first wedge and the
band.


Test for tightness of wedge:
 Press the tip of the explorer firmly at several
points along the middle two third of the
gingival margin to verify that it can not be
moved away from the gingival margin.


 The round tooth pick wedge is usually
the wedge of choice with conservative
proximal boxes because its wedging
action is more occlusal [ that is near
the gingival margin] than with the
triangular wedge.


 Triangular wedge is recommended for a
preparation with deep gingival margin, when
the gingival margin is deep the base of the
triangular wedge will more readily engage the
tooth gingival to the margin with out causing
excessive soft tissue displacement.


A suitably trimmed tongue blade can be
used as wedge where the inter proximal
space between the teeth is large.


Contact size;
Broadening the contact area:
 1. Creating a contact that is too broad bucco-
lingually or occlusogingivally, will change the
anatomy of the inter dental col.
 The normal saddle shaped area will become
broadened.
 As a result , the area for the development of incipient
periodontal disease , markedly increases.

 2. produces an inter dental area that the patient is
less able to clean that increases the area susceptible
to further decay.


 1. broadening the contact area will be at
the expense of dimensions and shape of
buccal and lingual embrasures. This will lead
to improper movement or flow of masticated
material.in turn this will lead to adhesion of
debris and possible intraproximal impaction of
that debris.

 2. finally brodening the contact area ,
could be at th eexpence of gingival
embrasure, so that the restoration could
encroach physico-mechanically on the inter
dental periodontium , predisposing to its
destruction.


Narrow contact area:
 Creating a contact that is narrow bucco-
lingually or occluso gingivally, besides
changing the anatomy of the tooth, will
allow food to be impacted vertically and
horizontally on the delicate inter dental
col . this will predispose to periodontal
and caries problem.


 A contact area placed too occlusally will result
in a flattened marginal ridge at the expense of
the occlusal embrasures.
 A contact area placed too bucally or lingually
will result in a flattened restoration at the
expense of buccal and lingual embrasures.
 A contact area placed too gingivally will
increase the depth of the occlusal embrasure
at the expense of contact area’s own size or
at the expense of broadening or impinging
upon inter dental col.



 A open contact creates continuity of the
embrasures with each other and with the inter
dental col. All of these defects in the contact
area will allow for the impaction of food and
accumulation of bacterial plaque, with
accompanying periodontal and caries
problems.

 There fore proper reproduction of the contact
size and location to imitate the natural
dentition is essential for the success of the
treatment and restoration of the proximal
surface.

 Contact configuration:
 Contact area that is flat can make it broad
buccally, lingually, oclusally, or gingivally. On
the other hand, a contact area with excessive
convexity will diminish the extent of the
contact area. Both will predispose to decay
and periodontal destruction. A concave
contact area will usually in restoring adjacent
teeth simoultaneously. It is accompanied by
the adjacent restoration with a convex
proximal surface.


 Besides broadening and mislocating the
contact area , the interlocking between
concavity and adjacent convexity can
immobilize the contacting teeth, depriving
them of normal, stimulating physiologic
movements, resulting in periodontitis or
mechanical break down.
 Also in restoration with a concave contact
area, it is impossible to create the proper size
of marginal ridge or adjacent occlusal
anatomy.


Contour:
Facial and lingual convexties:
 Normal tooth contours act in deflecting
deflecting food only to the extent that
the passing food stimulates by the
gentle massage of the investing tissues
rather irritate them .


 Effect of over contour:
 Facial and lingual convexities:
 Normal tooth contours act in deflecting
food only to the extent that the passing
food stimulates by gentle massage of
the investing tissues rather than
irritating them.


 Effect of over contour:
 The presence of supragingival, cervical third,
crown over contour presents a unique
biomechanical soft tissue environment such
as convexity extends as an awning over the
marginal gingival.
 This architecture was seen:
 1.      to leave a space for the accumulation of
debris
 2.      to prevent accumulation of food during
mastication.
 3.      to prevent approximation of tongue and
cheek for the possible removal of debris.


 Effects of under contouring:
 Under contoured crowns with flat
cervical surfaces may lead to thickening
of the gingival margin. Apparently,
under contouring is not nearly as
damaging to the gingivaas over
contouring. It has little if any effect on
gingival health.


Facial and lingual concavities:
 Those concavities occlusal to the height of
contour , whether they occur o anterior or
posterior teeth are involved in the occlusal
static and dynamic relations, as they
determine the path ways for mandibular teeth
in and out of centric.
 Deficient or mislocated concavities will lead
to premature contacts during mandibular
movements, which could inhibit the
physiologic capabilities of these movements.
On th eother hand excessive concavities can
invite extrusion, rotation or tilting of occlusal
cuspal elements in to non-physiologic
relations with the opposing teeth.

 Concavities apical to the height of
contour, are essential for proper
maintenance of the accompanying new
components of the adjacent
periodontium and must be imitated in
the restoration. Deficient concavities at
these locations can create restoration
over hangs, and excessive concavities
decrease the chance for successful
plaque control in these extremely
plaque–retaining areas.


 Areas of proximal contour adjacent
to the contact area:
 In addition to creating a contact area of
proper size, location and configuration,
it is also essential to restore to a proper
contour that portion of the proximal
surface not involved in the contact. This
would include the areas occlusal,
buccal,lingual,and gingival to the
contact area.


 Fabricating a restoration that does not
reproduce the concavities and
convexities which occur here naturally
will lead to restoratio over hangs and
under hangs,vertical and horizontal
impaction of debris, and impingement of
debris, and impingement upon the
adjacent periodontal structures.


 Marginal ridges:
 1. Absence
of
marginal ridge in
restoration:
.


 A marginal ridge with exaggerated
occlusal embrasure:



 Adjacent marginal
ridges not
compatible in
height:
 drive restored tooth
away -contacting tooth
 vertical forces will drive
debris interproximally.


marginal ridge with
no triangular fossa:
 no occlusal planes
occlusal forces to act,
 no horizontal
components drive teeth
towards each other.
 vertical forces impact
food inter proximally.


 1. marginal
ridge with no
occlusal
embrasure:
 two adjacent
marginal ridges will
act like a pair of
tweezers grasping
food substances
passing over it .


 A one planned
marginal ridge in
buccolingual
direction:


A thin marginal
ridge in the
mesiodistal bulk:
 susceptible to fracture
or deformation.
 shallow or deep
adjacent fossa or bulky
occlusal anatomy.


Micro machined matrix:

posterior composites
band thickness- 0.0015”
has 2 windows-0.0005”
contact areas contoured- slight
proximal convexity


 SuperMat:

 large posterior
restorations
 ringed Super Cap
matrices in clear
plastic and stainless
steel-SuperLock
tensioning instrument.


 advantages:

 Universal tensioning instrument

 No tightening device

 restoration of several teeth same quadrant same
time

 Greater patient comfort


 clear view of the working area
 Do not interfere with light curing
 Good anatomical shape
 Tight contact

 Height 5mm-6.5mm
 Thick ness 0.03mm metal
 Plastic 0.05mm


 Barton matrix:


 Palodent matrix
system:
 Matrix shape-natural
contours
 Flat contours


BiTine Round Ring

gently separates
teeth


BiTine Oval Ring :;:::

 gentle separation and matrix stabilization.
 more visibility
 longer tines assist stacking rings for MODs
.


 Palodent Standard
Matrix
 ideal for
posterior restorations.


 Palodent Mini Matrices

 ideal for deciduous restorations
 narrow and shallow
preparations proximal boxes.


 Palodent Plus
Matrix

 deep
proximal boxes.


Composi tight matrix:

 Similarto palodent matrix
 G- Rings


 V- RING MATRIX:
Patented v- shaped space between the tines
accomadates the wedges
Ni – Ti ring separates teeth
Spans wide cavities with out separating it


Tab matrix:
 Tab handle
 Holes in the wings of
the matrix-easy removal
 Pin tweezers
 Natural contour


 simple arc curvature-
tab matrices have S-
shaped curve - true
proximal surface


 Double banded Tofflemire:
Quint int o4, 271-73


CONTACTS AND CONTOURS IN CONSERVATIVE DENTISTRY / rotary endodontic courses by indian dental academy

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (12)

Similar to CONTACTS AND CONTOURS IN CONSERVATIVE DENTISTRY / rotary endodontic courses by indian dental academy

Similar to CONTACTS AND CONTOURS IN CONSERVATIVE DENTISTRY / rotary endodontic courses by indian dental academy (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

CONTACTS AND CONTOURS IN CONSERVATIVE DENTISTRY / rotary endodontic courses by indian dental academy