This document discusses dental contours and tooth separation. It describes the different contours on facial, lingual, proximal, and occlusal surfaces. Proper proximal contacts and embrasure spaces are important for stability, preventing food impaction, and protecting soft tissues. Matrices are used to form contacts and contours during restorative procedures. Various matrix systems and methods of tooth separation like wedges and separators are outlined. Maintaining ideal contacts, contours, and embrasure sizes is important for function and periodontal health.

1. MATRICINGANDTOOTH
SEPARATION

2. 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
• Facio-lingual contour
• Proximal contour
• Occlusal contour

3. CONTOURS:
• Contours on the facial and 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

4. CONTOURS:
• Contours on the proximal surface
• Teeth show convexities on the distal and mesial surface.
• The area with maximum convexity on the proximal
surface is called the proximal height of contour.
• Proximal height of contour responsible for the creation of
the
a)Proximal contact
b)Embrasure space

5. Proximal contact :
• Proximal convexity of the teeth create area of
contact between adjacent teeth with in the same
arch.
• These are called proximal contact area.
• Initially as teeth erupt the teeth contact each other
at a point(point contact).
• With the passage of time, physiologic tooth
movement causes frictional wear enlarging the
contact point to contact area.

6. Importance of contact :
• Preserves the stability and integrity of the arch by
maintaining normal mesio-distal relationship of teeth.
• Prevent food impaction interdentally
• Protect the soft tissue from periodontal disease
• Conserve the teeth from proximal caries
• Premature restorative failure does not occur if stable
proximal contact is present.

7. Size of contact :
• Anteriorly- contact point
• Posteriorly –contact area about 1.5-2mm
LOCATION OF CONTACT
• Anterior teeth – incisal one third
• Posteriorly - junction of incisal and middle one third

8. Embrasures :
• Embrasures are “V” shaped spaces present
interproximally around the proximal contact existing
between the adjacent teeth.
• Types
• 1.Buccal embrasure
• 2.Lingual embrasure
• 3.Incisal/occlusal embrasure
• 4.Gingival embrasure

9. Functions of Embrasures :
1)Serve as spillways for the escape of food during
mastication
2) Prevent trapping of food in to the contact area
3)Protect the underlying supporting tissue during
mastication

10. Over and under contoured restoration:
Over contoured restoration:
• They deflect food from the gingiva causing
poor gingival stimulation.
• The gingiva become flabby ,red and
chronically inflamed due to increased plaque
retention
Under contoured restoration :
• This result in irritation and trauma to the
attachment apparatus.

11. Too broad contact :
It will change the tooth anatomy
It will change the interdental ‘col’ by broadening it.
The delicate non keratinized epithelium may get damaged
increasing the chance of periodontal tissue.
With too broad contact the interdental area is difficult to
clean increase the risk of future decay

12. Too Narrow contact :
It will change the tooth anatomy
The embrasure size will increase leading to impaction of
food vertically and horizontally, thereby damaging
periodontal tissue.

13. Improper contact location :
• Too occlusally -It will cause flattening of
marginal - ridges, resulting in too shallow
occlusal embrasure
• Too buccally/lingually- will encroach upon
the respective embrasure
• Too gingivally - will reduce the size of
gingival embrasure and encroach upon
interdental gingiva

14. Open contact :
 Open contacts would create the problem ready inflow of
food causing accumulation of debris , plaque and damage
to the periodontal disease

15. Consequence of not restoring proximal
area :
• Food impaction----- recurrent caries
• Change in occlusal and inter-cuspal relations
• Trauma to the periodontium

16. Matricing :
• It is the procedure by which temporary wall is
built opposite to the axial wall, surrounding the
tooth structure which has been lost during tooth
preparation.

17. Matrix :
• It is an instrument which is used to hold the
restoration within the tooth while it is setting.

18. Depending on the type of band
material:
1. Stainless steel
2. Copper band
3. Cellulose acetate
4. Polyacetate

19. Based on mode of retention:
a) With retainer
b) Without retainer

20. Based on type of band
a) Metallic non transparent
b) Non metallic transparent

21. Based on type of cavity for which it is
use
a) Matrix for Class I cavity
preparation
b) Matrix for Class II cavity
preparation

22. c)Matrix for Class III cavity
preparation
d)Matrix for Class IV cavity
preparation

23. e) Matrix for Class V cavity
preparation

24. Based on its preparation
1. Custom made or anatomic
Ex: compound supported matrix
2. Mechanical matrix
Ex: Tofflemire, Ivory No.1 & 8
Matrices

25. Parts of matrix:
1. Retainer :
Holds the band in desired position and shape
2. Band :
piece of metal or polymeric material, intended to
give support and form to restoration during its insertion
and setting.

26. Band :
• It should extend 2 mm above the marginal ridge
height and 1 mm below the gingival margin of
preparation.

27. Width of matrix band :
• Permanent teeth- 6.35mm- 1/4th inch to 9.525 mm –
3/8th inch.
• Deciduous teeth- 3.175 mm- 1/8th inch to 7.9375 mm
– 5/16th inch
Thickness of matrix band :
0.0381mm (0.0015 inch) to 0.0508 mm (0.002 inch)

28. • Confine the restoration
while setting
• Provide proper proximal
contact and contour
• Provide optimal surface
texture for restoration
• Prevent gingival
overhang
Functions:

29. Ideal requirement of matrix band :
Rigidity
Adaptability
Easy to use
Non reactive
Height and contour
Application
Sterilization
Inexpensive

30. IVORY MATRICES
• The original Ivory matrix with a retainer was introduced in 1890.
• It was indicated for the restoration of two-surface cavities.
• The band extended around three-fourths of the crown of the
tooth and was retained by the projections of the jaws of the
retainer passing through holes in the band and engaging in the
facial and lingual embrasures on the side of the tooth
opposite the cavity

31. Ivory No 1 matrix and retainer:
 An adjustable metal retainer, holds bands of stainless steel
that provide the missing wall for the single proximal surface
restoration (MO or DO).
 In middle of band one margin is slightly projected, which is
kept toward the gingiva on the cavity side.
 Free end of matrix band are kept on the non cavity side.

32. Ivory No 2 matrix and retainer:
• The Ivory No 2 matrix and retainer were introduced in 1892 and
had a spring-loaded retainer.
• A yoke engaged the spring to tighten the jaws of the retainer
and band to the tooth.
• A screw could be placed in either end of the yoke thus making
the instrument universal.

33. Ivory No 3 matrix and retainer:
• The Ivory No 3 matrix and retainer were introduced in 1898 as
an improvement on the band matrices.
• The retainer held the band firmly and allowed for close
adaptation to the cervical of the tooth without damaging the
gingivae

34. Ivory No 4 matrix and retainer:
• Introduced in 1900
• The shapes and length of the wedges to increase separation.
• Gradual, continuous separation, and only during the restorative
procedure, was prescribed.

35. Ivory No 5 matrix and retainer:
• Introduced in 1900
• Indicated for the placement of two-surface restorations.
• The retainer operated much like the Ivory No 1 retainer and
differed only in design..

36. Ivory No 8 matrix and retainer:
• Introduced in 1905
• The band, instead of being engaged by the retainer, was
threaded and fastened into the vise of the retainer by the end
nut and adapted closely to the cervical of the tooth when drawn
into position by the middle nut.

37. Ivory No 8 matrix and retainer:
• INDICATION:
• Unilateral or bilateral Class II (MOD).
• Class II compound
ADVANTAGES:
• Economical
• Can be sterlized

38. Tofflemire matrix
• Designed by B R Tofflemire
• Indicated when two or three surfaces of posterior teeth has
been prepared.
ADVANTAGES:
• Ease of use.
• Good contact & contour
• Rigid & stable
DISADVANTAGES:
• Does not produce optimum contact & contour for posterior
composite
• Not useful for extensive class II

40. Types of Tofflemire matrix:
Based on type of head
• Straight
• Contra-angled
Based on type of dentition:
• standard used for permanent dentition
• small used for primary dentition

41. Clinical technique:
A- open large knurled nut
B- open the small knurled nut in opposite direction for
reception of matrix band
C- 2 ends of band are secured to form loop
D- for final adaptation of matrix band to tooth by tightening of
large knurled

42. Steele’s Siqueland Self Adjusting Matrix
Holder For Tapered Teeth:
• Used when there is significant difference between
diameters of cervical and occlusal one third of tooth.
• Advantages:
• Can adapt to tooth contour

43. Anatomical matrix band / Custom made
matrix compound supported matrix
• Described by Sweeney .
• Adapted over tooth with one healthy tooth on either
side.
• Wedges are placed
• Embrasure's are sealed with the help of self cure
acrylic/impression compound.
• Advantage:
• Provides better contact and contour
• Easy to remove
• Rigid and stable than other matrix system.

44. Retainerless Automatrix system
• Adjusted according to tooth shape & size.
• Auto matrix bands
• Automated II mechanical device
• Shielded nipper
Indicated : tilted and partially erupted teeth
complex amalgam restoration
Advantage: simple , convenient, better visibility

45. Precontoured Sectional matrix and contact
rings
• Consist of precontoured matrices (selected according to
tooth size)
• A flexible metal ring called as contact ring is placed to
stabilize the ends of matrix band against proximal box.
•

46. Tooth separation:
• The process of separating the involved teeth slightly
away from each other .
• REASON:
• Examination: proximal caries
• Preparation of teeth: Class II & III
• Polishing of restoration:
• Matrix placement
• Removal of foreign bodies

47. Slow or Delayed Tooth separation:
• Takes long time
• Methods of slow separation:
• Rubber ring
• Rubber dam sheet
• Ligature wire
• Gutta percha stick
• Oversized temporary crowns
• Fixed orthodontic appliance

48. Rapid tooth separation
• Traction principle:
• Uses mechanical devices which engages proximal area
of tooth with holding arms.
• Ferrier double bow separator
• Wedge principle:
Pointed wedge shaped mechanical device inserted beneath
contact area of teeth
• Elliot separator
• wedges