General Dentistry/
Matrix Systems
Chapters
48 & 49
Restorative Dentistry
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Indicated when teeth must be restored to their
original structure by the use of direct or indirect
restorative materials.
Conditions that determine the need for
restorative dentistry:
Initial or recurring decay
 Replacement of failed restorations
 Abrasion or wearing away of tooth structures
 Erosion of tooth structure
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Esthetic Dentistry
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Primarily devoted to improving the appearance
of teeth by either restoring imperfections with
direct or indirect restorative materials
Specific conditions that initiate a need for
esthetic treatment include the following
Discoloration due to extrinsic or intrinsic staining
 Anomalies caused by developmental distrubances
 Abnormal spacing between teeth
 trauma
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Cavity Preparation
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Process of removing unhealthy tooth structure
while leaving a limited amount of healthy tooth
structure for the tooth to maintain a restoration
Two stages:
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Initial preparation
Access to decay
 Outline form
 Primary resistance form
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Final preparation
Remove any remaining enamel in the prep
 Additional resistance and retention
 Place protective materials
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Terminology
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Cavity Wall:
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Internal wall:
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Internal surface of tooth prepared for the restoration
Cavity wall/surface that does not extend to the external tooth
surface
External wall:
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Surface of the tooth preparation that extends to the external
tooth surface, named according to the tooth surface involved;
distal, mesial, facial, lingual, gingival
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Axial wall:
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Internal wall/surface of the prepared tooth that runs
parallel to the long axis of the tooth
Pulpal wall:
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Internal wall/surface of a prepared tooth that is
perpendicular to the long axis of the tooth; also
known as the pulpal floor
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Line angle:
Angle formed by the junction of two walls/surface
in a cavity preparation (such as a corner)
 The names of the two walls are combined and form
a new angle. Such as mesial and lingual, and
becomes mesiolingual angle.
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Classifications
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Class I
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Class II
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Small and involves the pits and fissures of teeth
Extension of Class I, into the proximal surface(s) of
premolars and molars
Class III
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Affects the interproximal surface (mesial or distal) of
incisors and canines
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Class IV
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Involves larger surface area, that includes the incisal
edge and the interproximal surface of incisors and
canines
Class V
Smooth surface restorations
 Gingival third of the facial or lingual surfaces of any
tooth
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Complex Restorations
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When the loss of the tooth structure becomes greater
than the remaining natural tooth that is left.
Decision has to be made whether to restore with a
crown or direct restoration (such as amalgam or
composite)
If a direct restoration is decided upon, Retention Pins
may be needed. Pins provide stronger system for
retaining and supporting the restoration other than
retentive grooves or bonding materials
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Retention Pins
May be required when tooth decay has extended into
the distolingual cusp, undermining the enamel and
dentin.
 One pin would be placed for each missing cusp
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Veneers
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A thin layer of tooth colored material that is
applied to the facial surface of a prepared tooth.
Can be used for more than one tooth
Improves appearance, (such as)
Slightly abraded
 Eroded
 Dicolored (intrinsic stains or after endo treatment)
 Alignment (diastema)
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Tooth Whitening
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Also known as Vital bleaching
Noninvasive method of lightening of teeth
In office and at-home methods
Three primary indications for use
Extrinsic stains from foods, smoking, coffee or tea
 Aged teeth
 Intrinsic stains (tetracycline stains and mild fluorosis
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Typical Amalgam Tray Set-up
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Basic set-up
Hand cutting instruments
Condenser
Ball burnisher
Carvers
Amalgam carrier
Articulating paper/holder
Set-Up Cont.
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HVE/saliva ejector
Handpieces
Burs
Dental floss
Cotton rolls/holder
Misc.
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Matrix band/retainer
Guaze squares
Anesthetic set-up
Dental dam set-up
Matrix Systems
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Creates a temporary wall for amalgam,
composite resin or IRM material
Posterior Matrix systems
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Tofflemire retainer
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Know the parts of the retainer and their function
Band
Made of thin flexible stainless steel
 Center of the band must be contoured(shaped) in the
proximal surfaces for contact
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Matrix Cont.
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Wedges
Class II restoration require wedges
 Placed on lingual embrasure
 Various sizes and forms, wood or plastic
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Anterior Matrix
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Clear plastic
Used with composite resin or glass ionomer
Stainless steel matrix can scratch or mark the
composite resin material
Also referred to as celluloid strip or Mylar strip.
Automatrix System
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Alternative to the use of Tofflemire system
Does not use retainer to hold in place
Bands are already formed
Matrix Systems for Primary Teeth
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T-bands
Copper band in shape of a T
 When formed the top of the band allows the straight
portion to adjust and fit the circumference of the
primary molar.
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