THIS GIVES DETAILED ACCOUNT OF HOW TO RESTORE CLASS 4 CAVITY

1. CLASS IV COMPOSITE
RESTORATIONS
R PRANEETH,1ST YEAR PG
DEPARTMENT OF CONSERVATIVE
DENTISTRY AND ENDODONTICS

2. INDEX
1]DEFINITION OF CLASS IV CARIES
2]DIAGNOSIS OF ANTERIOR PROXIMAL CARIES
3]PREOPERATIVE EVALUATION OF OCCLUSION AND SHADE SELECTION
4]PREPARATION AND DESIGNS OF CLASSS IV
5]PULP PROTECTION ,BONDING ,PLACEMENT IN COMPOSITES
6]FINISHING AND POLISHING

3. DEFINITION
 Class IV: Cavity on proximal surfaces of incisors or canines that involve the
incisal angle (Class IV lesion is the larger version of Class III that covers the
incisal angle)[Black CE, 1940, Brace.]
 Class IV restorations involve only anterior teeth, an esthetic material such as composite almost always is indicated.

 Sturdevant’s 5th edition

4. Class 4:Interproximal Lesions Involving
the Incisal Angle
1]Interproximal lesions involving the incisal angle are usually the result of
undermining and compromising the integrity of the incisal enamel
2]This undermining can occur as a result of untreated large interproximal caries
or when replacing a large Class 3 restoration.
3]These lesions can occur due to an injury that results in a fracture of the
incisal angle.
SUMMITS,4TH
EDITION

5. CLASS IV DUE TO FRACTURE
1]The need for Class 4 restorations due to
traumatic fracture occurs most often among
children or young adults.
2]The frequency of fractures of permanent incisors
in children is reported to range from 2.4% to 20%.
3] Traumatic fractures are likely to be more
horizontal than vertical.
SUMMITS,4TH
EDITION

6. SHADE SELECTION-KEY TO SUCCESS IN
CLASSIV
 Proper shade selection may be more difficult for large Class IV
restorations that do not have normal dentin colorations.
 Accurate shade selection is attained by applying and curing a small
amount of the composite restorative material in the area of the
tooth anticipated for restoration.
 Shade selection should be determined before isolating the teeth to
avoid color variations that can occur as a result of drying and
dehydration of the teeth
Sturdevant’s5thedition

7. UNDERSTAND THE CONCEPT OF METAMERISM
BEFORE COMPOSITE SHADE SELECTION…………
 Use of separate translucent or opaque shades of
composite may be necessary
 Problems in color perception also complicate
selection of the appropriate shade of restorative
material.
 Various light sources produce different perceptions
of color. This phenomenon is referred to as
metamerism.
Sturdevant’s 5th
edition

8. SHADE SELECTION ………
Proper lighting:
 Commonly used fluorescent tubes emit light with a green tint that can distort color perception.
 Color-corrected light sources that approximate natural daylight are available and are recommended for
dental treatment
SUMMITS,4TH
EDITION

9. SHADE SELECTION……….
Environmental factors: The environment
influences the shade selection.
 To improve the accuracy of shade selection,
the color of the room walls and of the
patient and staff clothing should be neutral
to avoid imparting a negative color cast.
 Additionally, the patient should be asked to
remove lipstick prior to shade selection.
SUMMITS,4TH
EDITION

10. SHADE SELCTION ………….
 Color acuity and eye fatigue :When selecting color or shade,
the operator should avoid staring at the tooth and shade
guide for long periods of time.
 Staring at these objects during shade selection for more than
5sec will cause the colors to blend, resulting in a loss of color
acuity.
 The shade guide should be placed adjacent to the tooth to be
restored and then viewed briefly to determine which shade or
shades match the color of the tooth; then the eyes should be
moved away.
 Ideally, the eyes should be “rested” by viewing the horizon
through a window or by looking at an object that is a muted
blue, violet, or gray color.
SUMMITS,4TH
EDITION

11. Shade selection……..
 As previously mentioned color or shade selection should be accomplished
before the restorative procedure is initiated, prior to rubber dam placement
or cavity preparation.
 If patients have whitened their teeth, it is necessary to wait 2 weeks after
bleaching for shade selection and optimal bonding results.
 Teeth should be kept wet and hydrated during shade selection because
dehydration causes (1) significant lightening of the color and (2) an increase
in the opacity of enamel and dentin.
SUMMITS,4TH EDITION

13. Achieving optimal colour selection…….
 A major drawback of all the shade guides is the fact
that the shade of the underlying tooth is not taken into
account.
 To overcome custom shade tabs should be fabricated
for each shade of the resin composite material used in
the practice.
 The shades should then be arranged by value or
brightness, from light to dark
SUMMITS,4TH
EDITION

14. Colour selection…….
 These tabs are then held incisally adjacent to the tooth
to be matched, and the selection can be narrowed down
to three to four shades.
 For selection of the final shade, the middle portion of
the tooth should be observed and matched to the
closest of these shade tabs.
 The selected shade then becomes the overall or “basic
shade” of the restoration
SUMMITS,4TH
EDITION

17. TAKE AWAY
 SMALL AMOUNT OF THE SELECTED SHADE OF COMPOSITE SHOULD BE APPLIED ON
TOOTH TO BE RESTORED AND LIGHT CURED FOR 10sec SHADE SELECTION
 DENTIN SHADE SHOULD BE SELECTED FROM CERVICAL AREA AND ENAMEL SHADE
FROM MIDDLE .
 COMPOSITE SHADE SELECTION TO DONE BEFORE TOOTH IS DEHYDRATED

18. Preparation and Designs of class IV
 Two types of tooth preparations for CLASS IV:
 Beveled class 4 : This tooth preparation usually is indicated for large Class IV restorations
 Modified tooth preparation is indicated for smaller Class IV needs.
Sturdevant’s 5th edition

19. BEVELED CLASS IV CAVITY PREP………
1.Beveled class 4 : Restoring large proximal areas that also include the incisal surface of an anterior
tooth.
2.In addition to the etched enamel margin, retention of the composite restorative material in
beveled conventional Class IV tooth preparations may be obtained by groove or other shaped
undercuts, dovetail extensions, threaded pins, or a combination of these.
Sturdevant’s 5th edition

20. Beveled conventional tooth prep……..
 Class IV beveled conventional tooth preparations are
characterized by an outline form that occurs when the
preparation walls are perpendicular or parallel to the
long axis of the tooth.
 Round carbide bur or diamond instrument at high speed
with air-water coolant used and the outline form is
prepared.
 All weakened enamel is removed, and the initial axial
wall depth is established at 0.5 mm into dentin.
 If necessary, a calcium hydroxide liner and RMGI base are
applied.
= Sturdevant’s 5th edition

21. FACIAL BEVEL………
1]On the facial surface, a longer bevel is needed for better
esthetics.
2] This bevel has a 60-degree angulation and is 2 to 3 mm in
length.
3] The bevel presents a scalloped or irregular outline, has a
variable thickness, starts inside the dentinoenamel junction
(DEJ), and feathers and disappears onto the enamel surface .
4]The purpose of this long bevel is to make the composite
restoration blend onto the natural tooth structure.
SUMMITS,4TH EDITION

22. FACIAL BEVEL
 The facial bevel is often described as infinite because its margins are difficult
to detect after they have been blended with the disk and they appear to be
disappearing onto the surface .
SUMMITS,4TH EDITION

23. LINGUAL BEVEL………………..
 On the lingual surface, where functional requirements are more important,
the bevel should remain shorter than on the facial surface, limited to about 1
mm in length.
 The outline of the bevel can be straight and well defined.
 The bevel starts at the DEJ and has a 45-degree angulation
SUMMITS,4TH
EDITION

25. RETENTION IN BEVELED PREPARATION…..
 Retention form is provided primarily by the
micromechanical bonding of the composite to the enamel
and dentin.
 Additional retention may be obtained by increasing the
width of the enamel bevels or placing retention undercuts
 If retention undercuts are deemed necessary, a gingival
retention groove is prepared using a No. 1 ⁄ 4 round bur.
 It is prepared 0.2 mm inside the DEJ at a depth of 0.25 mm
(half the diameter of the No. 1 ⁄ 4 bur) and at an angle
bisecting the junction of the axial wall and gingival wall.
Sturdevant’s 5th

26. Modified Class IV Tooth Preparation
 . The modified Class IV preparation for composite is indicated for small or
moderate Class IV lesions or traumatic defects.
 The objective of the tooth preparation is to remove as little tooth structure
as possible, while removing the fault and providing for appropriate retention
and resistance forms.
Sturdevant’s 5th edition

27. MODIFIED CLASS IV ……
 Any existing lesion or defective restoration is removed with an appropriate-size round
bur or diamond instrument, and the outline form is prepared.
 Usually little or no initial tooth preparation is indicated for fractured incisal corners,
other than roughening the fractured tooth structure.
 The cavo surface margins are prepared with a beveled or flared configuration similar
to that of beveled preparation.
 The axial depth depends on the extent of the lesion, previous restoration, or fracture,
but initially is no deeper than 0.2 mm inside the DEJ.
 Usually no groove or cove retention form is indicated. Instead, the retention is
obtained primarily from the bonding strength of the composite to the enamel and
dentin.
Sturdevant’s 5th
edition

29. TAKE AWAY
 CLASS IV CAVITY MOSTLY INVOLVE BEVELED PREPERATIONS
 FACIAL BEVEL GIVEN AT 60 DEGREES ,2 TO 3 mm LENGTH GIVEN
 ON LINGUAL SIDE 1 mm BEVEL WITH 45DEGREES TO ENAMEL SURFACE GIVEN
 MODIFIED CLASS IV USUALLY INVOLVES MINIMAL PREPERATION
 MODIFIED CLASS IV RETENTION MOSTLY DEPENDS ON COMPOSITE BONDING STRENGTH.

30. FRAGMENT RE-ATTACHMENTCLASS IV
 Clinical trials have shown these reattachments to
be successful in terms of retention, in some cases
for more than 7 years.
 fragment may be reattached to the tooth by
etching and bonding the fractured surfaces.
 The transition between the bonded fragment and
the tooth is masked by preparing an enamel bevel
and placing composite and blending it over the
enamel surfaces.
 The bevels should not extend into the dentin to
allow the fragment to be repostioned correctly.
SUMMITS,4TH
EDITION

31. Pin retention class 4:
Although pin retention is sometimes necessary, the use of pins in composite restorations is discouraged
for several reasons:
(1) risk of perforation either into the pulp or through the external surface;
(2) pins do not enhance the strength of the restorative material ;
(3) some pins may corrode because of microleakage of the restoration, resulting in significant discoloration of
the tooth and restoration .
Sturdevant’s 5th
edition

32. Pin retention redundant ????
Despite these disadvantages, when a large amount of tooth structure is missing,
pin retention may be necessary to retain the composite restoration.
But Neumeyer etal concluded that there was only a small (10%) increase in
fracture resistance of large Class 4 resin composite restorations if pins
supplemented bonding.[ Gen Dent 1992]
Sturdevant’s 5th
edition

33. Pulp protection
 Pulpal protection measures for composite restorations are indicated primarily for direct pulp
cap procedures.
 If remaining dentin thickness less than 0.5 mm calcium hydroxide is used.
 If liner is used RMGI base is to used ,which helps in sealing area and prevents etchant from
dissolving liner.
Strudevants,5TH
EDITION

34. ETCHING PROCESS,
 proximal surface of the adjacent unprepared
tooth should be protected from inadvertent
etching by placing a polyester strip.
 Then a gel etchant is applied to all of the
prepared tooth structure, approximately 0.5
mm beyond the prepared margins onto the
adjacent unprepared tooth
 The etchant typically is left undisturbed for
15 to 30 seconds.
 The area is washed to remove the etchant. If
dentin is exposed, rather than air dry the
rinsed area, it may be better to use a damp
cotton pellet.
Sturdevant’s 5th edition

35. ENAMEL ETCHING DIAGRAM
SUMMITS,4TH
EDITION

36. Priming and Adhesive
1]The primer and adhesive is applied to all of the prepared tooth structure with a micro brush .
2] When applied, the adhesive is lightly dried with the air syringe to evaporate any solvent (acetone,
alcohol, or water) and eliminate any water in the selfetch bonding systems.
3]Then light curing done, Because these materials are resin based, they generally exhibit an oxygen-inhibited layer
on the surface after polymerization.
4] The composite material bonds directly to the cured adhesive, unless the oxygen-inhibited layer is contaminated
Sturdevant’s 5th edition

38. BONDING AGENTS GENERATIONS
SUMMITS,4T
H

39. TAKE AWAY
 ETCHING DONE BY PHOSPHORIC ACID 15-30 SEC AND WASHED
 IF DENTIN EXPOSED THEN WIPED WITH COTTON NOT AIR WASHED
 OXYGEN INHIBITION LAYER AFTER BONDING HELPS IN INCREASE SHEAR
STRENGTH.

40. MATRIX APPLICATION
 Placing the matrix first provides an opportunity to assess that the gingival cavosurface tooth
structure is sound and not fractured because of wedge insertion.
 There are two main types of matrices: (1) a clear polyester strip matrix and (2) a compound-
supported metal matrix.
Sturdevant’s 5th edition

41. Polyester strip matrix
 The polyester strip matrix also can be used for
most Class IV preparations, although the strip’s
flexibility makes control of the matrix difficult.
 This difficulty may result in an overcontoured or
undercontoured restoration
 Also, composite material extrudes incisally, but
this excess can be easily removed when contouring
and finishing.
 Folding the matrix at the position of the lingual
line angle helps reduce the potential under
contouring of that area of the restoration.
Sturdevant’s 5th
edition

42. CUSTOM LINGUAL MATRIX PLACEMENT
custom lingual matrix may be used for large Class IV
preparations.
CUSTOM LINGUAL MATRIX: The operator records the lingual
and, if possible, incisal contours of the existing restoration by
using a small amount of the silicone material, creating a
guide or index with which the new restoration will be
formed.
Alternatively, the operator fabricates the lingual matrix
Sturdevant’s 5th edition

43. CLASS IV RESTORATION USING LINGUAL
MATRIX
SUMMITS,4TH
EDITION

45. Final curing
 Then layers of enamel and dentin placed in increments and cured
 Light-cured composite is inserted and cured in 1- to 2-mm increments to reduce
polymerization shrinkage.
 If polyester strip matrix used care must be taken when closing the strip not to pull with
excessive force because the soft material is extruded incisally and results in an under
contoured restoration.
Sturdevant’s
5th edition

46. Overlay technique.
 An overlay technique also may be used for Class 4
restorations to obtain a combination of strength and
a very smooth surface.
 The bulk of the restoration is built with a hybrid
resin composite to provide strength.
 The final layer is a veneer of microfilled resin
composite to provide a smooth, glossy surface.
SUMMITS,4TH
EDITION

47. Layering technique….
 To achieve imperceptible polychromatic restorations, a
layering technique employing both enamel- and
dentinlike materials is recommended
 Selection of dentin and enamel shades is based on the
principle of the basic shade, in which the dentin like
material is one to two shades darker than basic shade
 Enamel like material is the same shade as the basic
shade.
SUMMITS,4TH
EDITION

48. CONTOURING OF COMPOSITE
FACIAL SURFACE:
 A flame-shaped carbide finishing bur or polishing
diamond is recommended for removing excess
composite on facial surfaces.
 Medium speed with light intermittent brush strokes
and an air coolant for contouring.
Sturdevant’s 5th
edition

49. Tinting and opaquing
 Tinting Masking agents should be applied in thin layers to
allow sufficient space for the overlying composite to
restore translucency.
 Use of the proper accessory shades can create the
appearance of dentin overlaid with enamel.
 Accessory shades can also be used to recreate the yellow
color seen in cervical areas or the translucency that
appears in incisal areas.
SUMMITS,4TH EDITION

50. FINISHING AND POLISHING
 Final finishing and polishing are achieved with rubber polishing
instruments , diamond-impregnated polishers, and sometimes
an aluminum oxide or diamond polishing paste
 For some locations, abrasive disks (degree of abrasive A
constant shifting motion aids in contouring and preventing the
development of a flat surface.
Sturdevant’s 5th edition
COMPOSITE
POLISHING
BURS
12 fluted
carbide bur

51. FINISHING AND POLISHING……
ON LINGUAL SURFACE
 Lingual excess of composite is removed, and a smooth
surface is produced using a round or oval 12-bladed
carbide finishing bur or diamond at medium speed with
air coolant and light intermittent pressure
 The appropriate size and shape used depend on the
amount of excess and shape of the lingual surface
 Proximal and Embrasure Areas. The proximal surface
contours and margins should be assessed visually and
tactilely with an explorer and dental floss.
 The floss is positioned below (gingival to) the gingival
margin and “shoe-shined” as it is pulled occlusally.

52. PROXIMAL AND EMBRASURE AREAS
FINISHING ……..
 A No. 12 surgical blade in a Bard-Parker handle also may be used because the curved shape of the blade
and the thin diameter make this instrument ideal for removing gingival overhangs.
 Further contouring and finishing of proximal surfaces can be completed with abrasive finishing strips.
 Some strips have two different types of abrasives (medium and fine) on opposing ends of the strip, with a
small area between where no abrasive is present to allow easy and safe insertion of the strip through the
contact area.
 The medium grit is usually zirconium silicate, and the fine grit is usually aluminum oxide.

53. Proximal and embrasure areas
polishing…
 This strip should not be drawn back-and-forth across the restoration in a
“sawing” manner.
 It should be curved over the restoration and tooth surface in a fashion similar
to that used with a shoe-shine cloth, concentrating on areas that need
attention .
 To open the lingual embrasure or round the marginal ridge, the lingual part of
the strip is held against the composite with the index finger of one hand,
while the other end of the strip is pulled facially with the other hand.
 Contouring and finishing the proximal surface, including the gingival margin,
also develops the general embrasure form around the proximal contact.

54. Composite polishing
……….
SHOFU RAINBOW TECHNIQUE
Polishing buff

55. EVALUATION OF OCCLUSION
 Occlusion evaluated by articulating paper and slide the
mandibular teeth over the restored area.
 Recontour the adjacent or opposing natural teeth (or
both), although care must be taken not to remove the
tooth’s centric or functional contact or injudiciously
remove too much tooth structure or restorative material
Sturdevant’s 5th edition

57. TAKE AWAY
 POLYESTER STRIP IS EASY BUT LEADS TO UNDER OR OVER CONTOURING
 CUSTOM LINGUAL MATRIX IS BEST WAY TO DO RESTORATION
 LAYERING TECHNIQUE IS BEST WAY TO PLACE INCREMENTS OF COMPOSITE FOR
GOOD ESTHETIC RESULTS
 EVALUATION OF OCCLUSION IMPORTANT FOR CLASS IV SURVIVAL
 FAILURE OF RESTORATION MOSTLY DUE TO ADHESIVE TECHNIQUE AND TYPE OF
COMPOITE USED

58. CRUX OF STEPS OF COMPOSITE CLASSIV
PREPERATION
SUMM

59. S
4

60. SU
ED

62. HOW TO BEVEL ??!!!!
 The bevel is prepared at a 45-degree angle to the external
tooth surface with a flame-shaped or round diamond
instrument .
 An enamel bevel of at least 1 mm should be placed around
the periphery of the cavity.
 Increasing the width of the bevel beyond 1 mm has been
shown to provide no additional strength.
 But a wider bevel may provide a more harmonious esthetic
blend between the resin composite and enamel.
Sturdevant’s 5th edition

64. Index cut back technique