3. Class I Amalgam Preparation Flashcards
Principles of Cavity Preparation
- ____ form
- Resistance form
- ____ form
- Convenience form
- Remove any remaining carious ____
- Finish the enamel walls – remove unsupported enamel
- ____ the cavity preparation
outline
retention
dentin
cleanse
Outline Form
Determined by:
Location and size of the carious lesion, defect, or faulty restoration
____ morphology
Finish margins in self cleansing or easily cleansable areas
Margins should end in sound ____
Kind of ____ being used
Resistance Form
Determined by:
____ form
dental
enamel
restorative material
box
Resistance Form
Wall angulations
Prepare the internal walls ____ to
the enamel rods/prisms
Cavity preparation depth
To provide bulk strength of restorative material
Internal line angles
Should be slightly ____ to minimize stress
concentration
Restorative material
Different materials have different needs to be met
parallel
rounded
Retention Form Determined by: \_\_\_\_ friction \_\_\_\_ Walls Undercut points and grooves Auxiliary retention: \_\_\_\_ Parallel grooves \_\_\_\_ Bonding
Convenience Form
Gain sufficient access to the lesion to facilitate ____ and instrumentation in the preparation and restoratation process
wall
convergent
dovetails
pins
visibility
Remove any remaining carious dentin
- for mild, moderate and large caries: start with ideal ____ form first
- then, remove remaining caries
Caries removal with a large round bur on slow speed and a spoon excavator
for gross caries:
ONLY time the ideal ____ form cannot be
obtained first.
Most of the structure is destroyed by this point.
Remove ____ first, evaluate what is left, and refine the preparation.
outline
outline
caries
- Remove any remaining carious dentin
RE-EVALUATE the preparation often to detect sound tooth structure:
____ feedback
Auditory feedback
____
Caries detecting dye is completely removed - Finish enamel walls
Remove all ____ enamel
tactile
texture
unsupported
- Cleanse the prepared cavity
Clean and dry for inspection
Once clean, it is ready to receive the
restoration
Sometimes medicaments are applied after cleansing, prior to the restorative step
– Not proven to be ____
Summary: goal of restorative treatment
Detect and Diagnose Caries
Assess Caries Risk
Remineralize where possible, depending on risk
ELIMINATE diseased tissue following the Principles of Cavity Preparation
Restore the tooth to form, function and esthetics
significant
Class I Lesion
Originates in structural
defects of teeth
____
Class I Locations
Most often on the ____ surfaces of ____ teeth
pits and fissures
occlusal
posterior
Class I locations
Also:
On the ____ and ____ surfaces of ____ teeth where grooves terminate
Remember: Can also be on the ____ surfaces of anterior teeth – mostly ____
buccal
lingual
posterior
lingual
Classification by Complexity
Simple
Prepared cavities involve only ____ tooth
surface
Classification by Surface One Surface Take the name of that surface Occlusal Buccal pit Lingual pit
one
Review: developmental anatomy
A failure in the fusion of enamel at the bottom of the grooves and fossae, causes the formation of deep invaginations that may extend as far as the ____.
Caries progression
The initial lesion develops on the lateral walls, following the direction of the ____.
The surrounding enamel can appear as ____ or opaque
enamel rods
discolored
Caries progression
Caries progression of the opposing walls continues.
Appears discolored or opaque, as in the previous stage.
Caries progression is ____ to detect at this stage. Radiographs assist in diagnosis
difficult
Caries Progression
Extensive destruction of the dentin follows-which undermines the covering enamel
Will ____ the occlusal surface
At the DEJ, the caries spread rapidly and ____ along the junction
darken
laterally
Caries Progression
At the DEJ, the cones of decay have a ____ relationship
base to base
Principles of cavity design/preparation
Outline form Cavosurface to include: All carious \_\_\_\_ All decalcified \_\_\_\_ All undermined \_\_\_\_ Posterior Occlusal Outline: Extend into the major developmental grooves \_\_\_\_mm
pits and fissures
enamel
enamel
1
Class I outline forms!
Know me!
Principles of cavity design and preparation
Outline form
Center the preparation on the major ____
Go around base of the cusps and make a smooth, continuous flowing outline
Never cut across ____: Preserves tooth structure May hit a _____
grooves
cusps
pulp horn
Principles of cavity design/preparation
Outline form
Isthmus Width
Central portion Isthmus
Large end of the 1P condenser ____
Extensions
large end of
the 1P condenser ____
loosely
snug
Principles of cavity design/preparation
Retention form
The shape of the cavity has to resist displacement or ____ of the amalgam restoration
Resistance form
The cavity must be prepared in such a way that the tooth and the restoration withstand ____ against the forces applied
removal
fracture
Principles of cavity design/preparation
Resistance form requirements:
- Isthmus width is restricted to a minimum width - No more than ____ the width of the occlusal table
- Depth iniformly ____mm pulpally into the DEJ
- Avoids fracture from ____
- Bulk thickness of amalgam achieved - Pulpal floor should be flat and smooth to to minimize ____
- use a hatchet
1/3
0.5
stresses
Principles of cavity design/preparation
Resistance form requirements:
4. Width and depth should be adequate to allow for sufficient bulk due to low ____ and ____ of amalgam
- The Buccal and Lingual walls are slightly ____ towards
the occlusal
-Follows ____
tensile strength
brittleness
convergent
enamel rods
Principles of cavity design/preparation
Resistance form requirements:
6. The Mesial and Distal walls slightly ____ occlusally following the ____ (parallel) at the marginal ridge areas
- Still maintaining
the original width of the marginal ridge
7. The Internal line angles are defined and slightly ____
-NOT sharp
diverge
enamel rods
rounded
Principles of cavity design/preparation
Resistance form requirements:
8. The external outline/cavosurface and internal walls are smooth and ____
continuous
Principles of cavity design and preparation
Convenience form:
The shape of the cavity must allow adequate ____ and ____
visibility
accessibility
Finishing/Refining:
Smooth outline, floor and wall; no irregularities
Margins are planed to remove any ____ enamel
Use a hatchet
Cleansing and Debridement:
Cavity is cleaned of debris with an air-water spray
Preparation must be as clean as possible before placement of restorative material
unsupported
Preparation Procedure: Mandibular Right First Molar #30 BO
Depth:
Just beyond the enamel layer into ____
Measure depth with Periodontal Probe:
____ mm at shallowest point of preparation (base of lingual groove)
____ mm at distal wall where the central fossa intersects distal cusp
DEJ
- 5
- 9
Preparation Procedure: Maxillary First Molar #3 O, OL
2 occlusal cavities due to oblique ridge
Mesial portion:
Includes mesial and
buccal occlusal grooves
Outline form curves around base of ____ cusp
Distal portion Extends onto lingual surface -Axial Wall Terminates in \_\_\_\_ of lingual surface
mesiobuccal
middle third
Preparation Procedure: Maxillary First Molar #3 O, OL
Lingual aspect
Prepared by moving the handpiece to keep the and bur ____ to lingual surface
Preparation perameters
____ mm depth in the mesial pit, central pit, distal pit and lingual groove area
Isthmus width large 1 P ____
Extends into buccal groove ____ mm (large 1P)
OL groove width of ____
Axial wall ____ mm deep
(large hatchet)
perpendicular 1.5 loose 1 large 1P 1.5
Preparation Procedure: Maxillary First Molar #3 O, OL
Resistance Form:
____mm depth of pulpal wall
____mm width of gingival wall (B-L)
B and L walls ____ occlusally
M and D walls ____ slightly
Lingual walls ____ lingually
Pulpal wall ____ to long axis
of tooth
Pulpal wall slopes ____ following occlusal contour in the OL groove portion
1.5
1.5
converge
diverge
converge
perpendicular
occlusally
Preparation Procedure: max first molar
Resistance Form:
Pulpal Wall of OL Preparation: Slopes ____
Lingual Portion
Axial wall will slope to follow ____ surface contour
pulpoaxial line angle
occlusally
lingual
Preparation max first molar
Resistance Form:
Gingival wall ____ to long axis of tooth
Axial wall slightly convex/almost ____ mesiodistally, following M-D lingual contour
Axial wall ____ occluso-gingivally, following O-G lingual contour
Axiopulpal line angle ____
Well-defined line and point angles
Smooth pulpal and lateral walls
perpendicular
flast
convex
rounded
