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Cavities found on the proximal surfaces of the anteriorteeth involving the incisal angle
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True Class IV caries involving the incisal angle(mesioincisal or distoinicsal)
Non Classical Class IV fractured angle or abradedangle
Types of ClassIV
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1. No definite outline form
2. 45 degrees bevel from CSM
Purpose of bevel:
- increase area of retention
- to have room for material
- to dissolve interprismatic substance and createmicroporosities
- for good enamel-restoration interface
Characteristics:
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1. Gingival floor enamel is thin and access is difficult,
beveling may result in loss of retention form anddifficulty in maintaining proximal contour duringrestoration.
2. Incisal area will result in a thin resin extension
covering the bevel on an incisal edge where masticatorystress is often the highest and fracture is likely to occur.
3. Lingual area
Areas not beveled:
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Procedures:
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1. Shade Selection
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Shade Selection
Use natural lighting.
Avoid staring at the toothand shade guide for longperiods of time ( May causecolors to blend resulting toloss of color acuity).
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2. Cavity Preparation
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3. Polishing and Cavity Debridement
Use of prophy paste WITHOUT fluoride
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4. Application of Calcium Hydroxide
(if necessary) or Type III GICClass A and Class B no need for base
Function of Liners and Bases:Serve as barrier to an irritating chemical in the
restorative material applied during procedure
Aid in the attainment of a healthy pulpalresponse
* Prior to the next procedure, you are required to fitthe preformed crown
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5. Acid etching
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All debris and pellicle remnants are removed fromthe surface to enhance adaptation of the resin
Surface energy of the freshly etched enamel isaltered, making the surface more reactive andimproving the wettability of the polymer on enamel
Acid solutions of suitable concentration cause
dissolution of the exposed ends of enamel rods This dissolution creates surface irregularities that
increase the roughness and provide a greater surfacearea upon which the polymer can attach.
Objectives:
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Blot Drying with the use of cotton pellet
Remove etchant using air & water syringe.
6. Washing off acid etchant
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7. Application of bonding agent
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Gentle stream of air is used to remove excessbonding agent that pools in restricted areas of the
preparation and to insure uniform thin layer on theentire surface
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8. Incremental placement of composite
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9. Curing
20 seconds per increment
Factors of polymerization:
Thickness of the increment
Intensity of the light beam
Translucency of the resin
Number, size and distribution of fillerparticles
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10. Trimming and polishing
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11. Check Occlusion
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Color change or shade mismatch
Excessive wear
Loss of contour
Failure and replacement of Class IV restorationis most often associated with:
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Before After
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Before After
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