Clas II. caviry recapitulation
Name parts of this cavity, name the walls. What is MO. Od and MOD cavity? Wnhat is isthmus, where we find
it?
Occlusal cavity Proximal cavity (proximal box)
MO, OD – one proximal wall is affected, mesioocclusal cavity (MO)
or distal – occlusodistal cavity (OD)
MOD . Both
proximal walls
are affected
lroubal@med.muni.cz
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Pulpal walls
Axial wall
Gingival wall
Isthmus (between occl. and prox.cavity, the most narrow part
Which two main types of the class II.
preparation do you recognise?
1. Conventional preparation acc. to Black –
compoused cavity
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Proximal cavityCcclusal cavity Proximal cavity
Sedelmayer
2. Slot preparation
Principle Detail
The cavity does have
not extension on
occlusal surface,
it is open occlusally
Slot preparation – defect, cavity and filling
When the composite fillings can be used?
Composite materials – indications II.class
̶ Small – moderate cavities
̶ Large cavities - onlay, inlay, crown
̶ Dry operating field (absolutely) – rubberdam
̶ Excellent oral hygiene
̶ Patients compliance
Amalgam does not have the substitution – maybe bulk composites – the topic of one of the next lectures.
Which contraindications of composite
filling materials do you know?
See indications
How do we prepare the enamel margins for
composite materials in class II.?
Preparation of enamel margins
➢Enamel on axial walls must be beveled (red coded diamond)
and also the outer edge of the gingival wall must be beveled (if the
gingival wall is situated in enamel)
Also hand instruments (chisels) can be used for the gingival wall
Interproximal vertical margins
Yes
No
Kompozit
Amalgám
How do we establish the position of the
axial walls?
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Study the contact area (contact point):
The axial walls (cavosurface margins) are
approx. o 0,5 mm vestibulary and orally
Over this area.
The contact of the treated tooth is made
of the restorative materials.
Axial walls
Gingival wall is parallel with the
cementoenamel junction
and it is situated appr.
0,5 mm below free gingiva.
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v
American rule (estimation)
Tangents from the middle of treated tooth
to the next tooth – where these cross the treated
Tooth there are borders of the preparation
How do we protect the teeth next to the
preparared tooth?
Definujte zápatí – název prezentace nebo pracoviště19
Protection of the neighbour tooth
̶ Wooden wedges and the metal strip
̶ Special plastic wedges with the
̶ metal foil
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Which tool is necessary when one or more
proximal walls are missing?
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Matrix
➢Matrix primarily is used when a proximal surface is to be restored
The objectives:
- Provide proper contact
- Provide proper contour
- Confine the restorative material
- Reduce the amount of excess materiál
In some cases id important for good setting of the material
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Matrices for II.nd class
Circular and sectional matrices
➢Circular matrices round the tooth
They are used in combination with the matrix retainer.
➢Sectional matrices do not round the tooth, the proximal surface
only.
Matrix Hawe Neos
Matrix retainer ivory 8
(universal or paired)
Circular matrix
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Which tools are here in this picture?
lroubal@med.muni.cz
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matrix band matrix retainer wedges
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Which function does the wedge have?
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Wedges
➢ Wooden wedges
- tighten the matrix band
- compress the gingiva
- separate the teeth
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Wedging
➢Slip the matrix band over the tooth (apical to the gingiva margin –
0,5, - 1 mm)
➢Tighten the matrix, check it with probe
➢Place a wedge
➢Turn the retainer ¼ counterclockwise
➢ Contour the band
Segmental (sectional) matrices
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What do we need for the work with
sectional matrices?
Tools for the work with sectional matrices
Separator (separation ring)
- Forceps (for rubberdam clamp or similar)
- Wedge
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Various types of separators
Describe sequences of operation by
making the composite filling – class II.
Sequence of operation
̶ Preparation
̶ Bevel the enamel on axial walls and outer edge of gingival wall (if
located in enamel)
̶ Placement of the matrix
̶ Adhesive procedure (acid etching, washing, priming and bonding)
̶ Placement of the composite materiál layer by layer
̶ Curing
̶ Finishing and polishing
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Why do we perform the incremental
technique? (Layer by layer?)
Definujte zápatí – název prezentace nebo pracoviště36
The materiál must be placed layer by layer,
max 1.5 mm
̶ Good polymerization
̶ Decreasing of the polymerization stress which is connected with
the polymerization shrinkage (explanation in next lecture)
̶ Aesthetics