Class II. cavity preparation
Defects affecting one or bot proximal surfaces of posterior teeth.
Symptoms
> Increased sensitivity (cold, sweei
> Retention of food
open - the e
> Bite sensitivity (when carious lesion is open
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Diagnosis
> Vi
> Transillumination
> Radiography
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3
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ľ
Preparation - amalgam
rules
> Slot preparation
t ... , :
.  / \ • i
> Large preparation — cusp(s) invoivea
Preoaration -  adhesive materials
> Conventional preparation for composites
> Adhesive slot
> Tunnel preparation
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Conventional preparation
Isthmus
Access to the cavity
occiu
Through the undermined enamel
Separation using wooden wedges is useful
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Pre op
Pr
Cavosurface margin
Axial wedges
Under the free gingiva Occlusal
Class I. cavity preparation
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Retention
> Occlusal cavity surface
ccl
> Undercuts
> Grooves
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Axial walls
are divergent
in the gingival direction
Verical and horizontal grooves
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Resistance
o undermined enam
> No sharp wed
> Isthmus is 1/3 — 1/4 intercuspal distance
> Angle between axial and gingival wall: 90°, or 85°
> Width of gingival wall is 1 mm at least
> Thickness of the filling 2 — 4 mm (4mm cusp replacing)
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Excavation of carious dentin
Round bur (ball) or excavator
El
(Caries Detector, Kuraray, Japonsko; Caries Marker, VOCO,Německo)
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Finishing of cavity walls
> Red coded diamond bur
gingival wall (if in e
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Cavity control
> Goog light
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Isthmus
Matrix placement
lyi
is to be restore he objective Provide proper contact Provide proper contour Confine the restorative material Reduce the amount of excess material
urf
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Matrices — matrix band, matrix
retainer
> Ivory I retainer Ivory
> Hawe Neos retainer Ivory 8
> Toff
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Wedges
dges
- tighten the matrix band o the compression of the
- separate the teeth
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Wedging
> s:
the gingival margin — 0,5, - 1 mm
5^5
> Tighten the matrix, check it with prob
> Place a wedge
> Turn the retainer % counterclockwise
> Contour the band
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Condensation of amalgam
ondensor — S
traig
Power driven condensation
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Instruments
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