Clinical technique for complex Amalgam Restoration
Answers of lab cons
1. 1) What are the dental instrument parts? What are the
advantages of contra angle?
Most dental instruments are composed of three parts
1:handle
2:shank
3:blade or nib
Advantage of conta angle
To bring the cutting edge into near aligment with the long
axis of handle to provide balance ,to facilitate control of
instrument during application of force , and avoide
twisting of the instrument .
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2) Write the principles achieved by
A: Parallel wall : to provide retention form ,opposing walls of
occlusal restorations shoud be parallel to each other or
should converge occlusally, enamel rod in most areas of the
occlusal sur are directed roughly parallel to the long axis of
the tooth .
B: cavo-surface angle.
To enhance their ability to resist fracture , so
enamel margins should be prepared at 90 degree
or more abtuse angle
c) rounded angle
to avois stress concentration and distribution of
force
c: removing undermined
2. the enamel at the margin of the preparation should
be supported by sound dentin, any enamel that has
been undermined should be removed
wide opening and extension:
Extending around the cusps to conserve tooth structure and
prevent the internal line angles from approaching the pulp
horns too closely.
keeping the facial and lingual margin extension minimal as
possible between the central groove the cusp tips.
Minimally extending into the marginal ridges (only enough
to include the defect) without removing dentinal support.
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6) Define Dental caries using mineral word and mention
plaque classification?
Dental caries is aprocess which may take place on any
tooth surface in oral cavity where amicrobial film is
allowed to develop for aperiod of time
Classifications
Class 1 :caries affecting pits and fissures
Class 2:caries affecting the proximal sur of posterior teeth
Class3 :caries affecting the proximal sur of anterior teeth
Class4 :caries affecting approximal sur of anterior teeth
and involving the incisal edge
Class 5: caries affecting the cervical surface
3. 7) The main principles of cavity preparation in class 1 and
define each one?
1:establish out line form , out line form is based primary
on the location and extent f carious lesion,tooth fracture
2:obtain resistance form :resistance for the remaining
tooth structure and to restoration ,so the restoration is
resistance to displacement and both restoration and tooth
structure are resistance to fracture
the shape given to a prepared tooth to enable the restoration and remaining
tooth structure to withstand masticatory stress
3:obtain retention form:prevention of dislodgment of
restoration along the path of insertion,the provision made
in a prepared tooth cavity to hold in place a restoration
and to prevent its displacement.
4:obtain convenience form
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8) Mention 2 goals of amalgam burnishing?
1:shaping the occlusal surface of restoration
2:aiding in condensation
3:avoid marginal infiltration
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9) Mention five elements in the amalgam capsule?
4. Mercury , silver . tin , copper,zinc , indium ,
palladium
10) Mention three advantages of contra angle shank.
1: To bring the cutting edge into near aligment with the
long axis of handle to provide balance
2: ,to facilitate control of instrument during application of
force
3: and avoide twisting of the instrument and prevent
rotation and modified access
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Caries 3, where this caries involve and what its clinical
appearance?
Class3 :caries affecting the proximal sur of anterior teeth
Opaque chalky region (white spot )
5) What are the benefits of thin layer of flowable
composite under packable composite?
Base and isolater