All details about contact and contours of teeth

1. CONTACT AND CONTOURS
Presented by :
Nischala Chaulagain
BDS final year
Roll no 15
Presented to:
Dr. Amit Singh
Department of Conservative
and Endodontic

2. CONTENTS:
• Fundamental Curvatures
• Proximal Contact Area
• Labial And Buccal Contours
• Benefits of an Ideal Contact and Contour
• Tooth Movement
• Wedges
• Matrix
• Recent Advances

3. 1. Proximal contact areas
2. Interproximal spaces (formed by
proximal surface in contact)
3. Embrasures (spillways)
4. Labial and buccal contours at the cervical thirds (cervical
ridges) and lingual contours at the middle thirds of crowns
5. Curvatures of the cervical lines on mesial and distal surfaces
(cementoenamel junction [CEJ]) –
Fundamental Curvatures

4. Proximal contact area
The area of proximal height of contour of the mesial or
distal surface of a tooth that touches its adjacent tooth in
the same arch.
Initially called proximal contact point .

5. According to their general shape:
1. Tapering type: Wide crowns &
narrow cervical region
2. Square type: Bulky, angular with little
rounded contour
3. Ovoid type: A transitional type between tapering & square
types. Surfaces are convex but infrequently they may be
concave

6. Labial And Buccal Contours
CONTOUR : Refers to the outline of a structure. The facial
and the lingual surfaces of teeth possess some degree of
convexity.
Labial contour is present at the cervical thirds (cervical
ridges) and lingual contours at the middle thirds of
crowns

7. Height of contour
The area of greatest circumference on the
facial and lingual surfaces of tooth is called
height of contour.
In posterior teeth, height of contour is located in
the gingival third of facial surface and middle
third of lingual surface.

8. It protects the gingival tissue by preventing food
impaction.

9. EMBRASURES
These are V-shaped spaces that originate
at the proximal contact areas
between adjacent teeth.
They are named according to the direction towards which
they radiate.
These embrasures are facial, lingual, incisal/ occlusal &
gingival.

10. Benefits of an ideal contact and contour
• Conserves health of periodontium
• Prevents food impaction
• Makes the area self cleansable
• Improves the longevity of proximal restorations
• Maintains the normal mesiodistal relationship of teeth in
the dental arch

11. Hazards Of Faulty Reproduction Of
Contact & Contour
BROAD CONTACT
1.Changes the anatomy of the interdental col.
2.Produces a less cleansable interdental area.
3.May encroach on the embrasures.
NARROW CONTACT
1. Causes food to be impacted vertically/
horizontally in the col area.
2. Predisposes to periodontal and caries problem.

12. CONTACT AREA PLACED TOO GINGIVALLY
1. Impinges on the interdental papilla.
2. The contact size is decreased.
CONTACT AREA PLACED TOO OCCLUSALLY
1. Shallow occlusal embrasure.
2. Flattened marginal ridge.

13. IMPROPER CONTOUR
• Under Contour: Causes impingement of food into soft tissue.
• Over Contour: Deflects food away from gingiva resulting in
understimulation of supporting tissues
• Adequate Contour : Stimulation of supporting tissues
: Healthy peridontium

14. Procedures For Creating Proper
Contact & Contour
INTRAORAL PROCEDURES
1. Tooth movement:
a)Rapid tooth movement
b)Slow tooth movement
2. Matricing

15. a)Rapid tooth movement:
• Mechanical type of separation
• Creates either proximal separation at the point of
separator’s introduction and/or improved closeness of
proximal surface of opposite side.
Indications:
• As preparatory to slow movement
• To maintain the space gained by slow movement

16. • Wedge method
By insertion of a pointed wedge shaped
device between the teeth.
The more the wedge moves facially or
lingualy, greater is the separation.
• Elliot's Separator
Indicated for short duration separation
that does not necessitate stabilization .
Useful in examining proximal surfaces
in final polishing of restored contacts

17. Wood/ Plastic Wedges :
Used in both tooth separation for preparation and
restoration
Triangular shaped wedges (wood/synthetic resin)
Cross-section base of triangle will be in contact with
interdental papillae.
Two sides of the triangle should coincide with the
corresponding 2 sides of the gingival embrasure.
Apex must coincide with the gingival start of the
contact area.

18. Functions :
• Hold the matrix band in position
• Slight separation of the tooth
• Provides space for placing matrix band
• Prevent gingival overhang
• Stabilizes matrix and retainer
• Assure close adaptability of matrix band to the tooth
• Protect interproximal gingiva from unexpected trauma

19. Types:
Wooden
Plastic
Elastic
Transparent
Medicated wedges
Shape:
Triangular
Round
Trapezoidal

20. Wedging Method
Location : Gingival embrasure just beneath the contact area.
Selection : Depending upon the clinical situation. Wooden
wedges can be trimmed using a knife or scalpel blade to
produce a custom fit.
Placement : From the lingual embrasure which is normally
larger in size. But if it interferes with the tongue it may be
placed from the buccal side.
Length : so that it does not irritate the tongue or the cheek.
After placement the wedge should be firm and stable.

22. Wedging techniques

23. 1. Single wedge technique:
Single wedge is placed in the gingival embrasure.
The pointed tip is inserted from the lingual embrasure,
slightly gingival to the gingival margin.

24. 2. Piggyback wedging :
This type of wedging is particularly
useful for patients whose
interproximal tissue level has
receded.
Second (usually smaller) wedge may
be placed on top of the first to
wedge adequately the matrix
against the margin

25. 3. Double wedging technique :
Here, 2 wedges, one from the facial embrasure and the
other from the lingual embrasure are used.
Used when proximal box is wide faciolingually. •
Should be used only if the middle 2/3rd of the proximal
margins can be adequately wedged.

26. 4. Wedge wedging technique:
Used in cases when there is a gingival
concavity as in the case of a fluted
root.
In order to wedge a matrix band tightly
against such a margin, a second
wedge is inserted between the first
wedge and the band.

27. Triangular wooden wedges are more
recommended since:
Easy to trim and adapt well to tooth surface
When properly shaped, they remain stable
during condensation
Absorb moisture and swell to provide adequate
stabilization
Wooden wedges can be cut from toothpicks

28. Error’s with wedge placement :
If wedge is placed more occlusal to the gingival
margin, creates abnormal concavity in the
proximal surface of the restoration.
If wedge is for apical to gingival margin, band
will not be held tightly against the gingival
margin & creates gingival overhangs in the
restorations.
Tightness of the wedge is tested by pressing the
tip of an explorer firmly several points along
the middle 2/3rd of the gingival margin
against the matrix band.

29. b) Slow/ Delayed Tooth Movement
Indications:
When teeth have drifted and/or tilted considerably, rapid
movement of the teeth to proper position will endanger
the periodontal ligaments.
Therefore slow tooth movement over weeks will allow
proper repositioning of teeth in physiological manner.
Methods:
• Separating wires, Elastics
• Oversized temporaries
• Orthodontic appliances

30. Matrix –
Matrix is a device that is applied to
a prepared tooth before the insertion
of the restorative material to assist in the development
of the appropriate axial tooth contours and in order to
confine the restorative material excess.
Primary function of a matrix is to restore the anatomic
contours and contact areas.
Parts of a Matrix system involves:
• Band
• Retainer

31. Qualities of a good matrix includes:
1. Rigidity
2. Establishment of proper contour
3. Prevention of gingival excess
4. Convenient application
5. Ease of removal

32. Classification of Matrixes:
1. Based on mode of retention:
i. With retainer (Tofflemire matrix)
ii. Without retainer (Automatrix)
2. Based on type of band
i. Metallic non transparent
ii. Nonmetallic transparent
3. Based on type of cavity for which it is used
i. Class I cavity
a. Double banded Tofflemire (barton’s matrix)
ii. Class II cavity
a. Single banded Tofflemire
b. Ivory matrix No. 1
c. Ivory matrix No. 8
d. Copper band matrix
e. Automatrix
f. Anatomic Matrix
iii. Class III cavity
a. Mylar strip
b. S-shaped
iv. Class IV cavity form
a. Mylar strip
b. Transparent crown matrix
c. Modified S-shaped
v. Class V
a. Window matrix
b. Cervical matrix

33. TOFFLEMIRE/UNIVERSAL MATRIX
Designed by B.R. Tofflemire.
Ideally indicated when three surfaces
(i.e., mesial, occlusal, distal) of a
posterior tooth have been
prepared.
It may be positioned on the facial or
lingual aspect of the tooth.

34. Advantages:
• Can be placed facially/ lingually
• Retainer and band are stable when in place
• Retainer is separated easily from the band
• Retainer helps to hold the cotton roll (for isolation) in place

36. Matrix Bands
1. Uncontoured bands
• Available in 2 thickness : 0.002” and 0.0015”
• Burnishing the thinner band to contour is more
difficult and less likely to retain contours
2. Precontoured bands
• Needs little or no adjustment
• Expensive
• Difference in cost justified by lesser chair time.

38. Automatrix System
The automatrix system is an alternative to a
universal retainer.
There is no retainer used to hold the band in place.
Bands are already formed into a circle and are
available in assorted sizes in both metal and
plastic.
These are designed to fit all teeth regardless of
circumference and height.
Types:
• 3/16” (4.8mm), 0.002” thickness
• 1/4” (6.35mm), 0.002” & 0.0015” thickness
• 5/16” (7.79mm), 0.002” thickness

39. Advantages:
• Convenience
• Improved visibility because of absence
of retainer
• Ability to place the autolock loop on
facial/lingual surface
Disadvantages:
• Band is flat, difficult to burnish
• Sometimes unstable even with the use
of wedges
• Development of proximal contour is
difficult.

40. S-shaped Matrix Band
• 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

41. • Compound material is used to hold the band in
position in the facial and lingual aspect and also in
the gingival aspect.