Class II Prep Review and Amalgam Restoring Review Flashcards
1
Q
Class II caries
A
proximal of post teeth
2
Q
Another name for Class II
A
smooth surface lesion
3
Q
Where lesions are for class II
A
• Conical penetration through enamel • At DEJ, lateral spread
• Conical penetration through the dentin (apex toward the
pulpal tissues)
Lesions typically initiate just gingival to the
contact area
4
Q
Where Class II penetrates and shape
A
• Conical penetration through enamel • At DEJ, lateral spread
• Conical penetration through the dentin (apex toward the
pulpal tissues)
Lesions typically initiate just gingival to the
contact area
5
Q
Diagnosis of class II visually
A
chalky, opaque but only if dry and well lit
6
Q
Once lesion has penetrated what we do a class II
A
DEJ-some other considerations
7
Q
Best diagnosis of Class II lesion
A
Radiographic BW is the best-but does show less caries
8
Q
Teeth that fracture most likely do not have what line angles
A
Rounded axial line angles-so fix it
9
Q
Class II which was previously unrestored-when to treat it
A
- Generally, when the DEJ has been penetrated by decay
- Modifying factors:
- Poor OH, high caries risk, socioeconomic status and/or age (young) • May opt to restore if 2/3 the enamel has been penetrated = clinical judgment
10
Q
Class II which was previously restored-when to treat it
5
A
- Fractured restoration • Gingival overhang (excess)
- Non-physiologic contours
- Light or no proximal contact
- Poor marginal integrity
11
Q
Prep Class II using what vision
A
Indirect
12
Q
terminate on cusp margins in class II?
A
NO
13
Q
General amalgam preparation principles apply (8)
A
- Do not terminate margins on cusp tips
- All friable/weakened (unsupported) enamel should be removed
- Preserve cuspal/marginal ridge/transverse ridges for strength
- Avoid extension to unaffected fissures
- Preserve cuspal inclines
- Smooth curves, no sharp edges
- Pulpal depth 1.5mm from pits/grooves
- 90° Cavosurface margins
14
Q
pulpal depth of Class II amalgam prep
A
1.5mm
15
Q
Factors that contribute to Outline Form Clinically (5)
A
- Tooth anatomy: pits & fissures
- Adjacent structures (hard and soft tissues)
- Buccal and Lingual embrasures
- Gingival embrasures
- Contacts with adjacent structures must be broken
16
Q
How much room between contacts in class 2
A
• Approximately 0.5mm or the tine of the explorer
17
Q
Class II Resistance Form
A
90 degree cavosurface margin angles
Internal walls placed in dentin (0.5mm)
Flat pulpal floor
Flat gingival floor/seat
“Rounded” axio-pulpal line angle (and other internal line angles)
Divergence of appropriate wall (when applicable)
Adequate pulpal depth
Preservation of unaffected structure
18
Q
Internal walls of Class II prep depth
A
Internal walls placed in dentin (0.5mm)
19
Q
Retention form of Class II prep- O or proximal?
A
The occlusal and proximal portions should be
independently retentive
20
Q
Retention form of Class II (4)
A
- Convergent occlusal walls
- Occlusal dovetails
- Convergent proximal walls
• “Proximal locks” = proximal retention
grooves*
—-Convergent & more prominent gingivally
because they fade out occlusally
—-Placed 0.5mm inside DEJ • *When utilized
21
Q
when used, where are proximal locks placed
What are their walls like
A
• Convergent & more prominent gingivally
because they fade out occlusally • Placed 0.5mm inside DEJ • *When utilized
22
Q
Always use proximal lock on class II?
A
NO-only extensive preps
23
Q
Walls of Class II (converge, straight, diverge)??
A
- Convergent occlusal walls
- Occlusal dovetails
- Convergent proximal walls
Class 1 part is just like usual
24
Q
Convenience form of Class 2, how to obtain it?
A
• Generally obtained by cutting through the occlusal (and marginal
ridge) to access the proximal lesion
• May require additional extension for access or vision
25
More decay beyond bulk of it on class II prep, do what?
Only extend to caries, not all of the walls
26
Evaluate the soft tissue after a class II, what may be needed?
Hemorrhage control may be necessary
27
Isthmus width of class II
Isthmus width at ¼ the
| intercuspal distance
28
Axial wall contour of class II
Axial wall follows the external
| contour of the tooth
29
gingival floor seat dimension is what on class II
Gingival floor/seat dimension is
1.0-1.5mm axially • Maintain marginal ridge width
for strength
30
Tofflemire Matrix System
| used for
Used for amalgam restorations
| • Generally NOT used for composite resin restorations*
31
Components of Tofflemire Matrix System
Two main components: retainer & bands
32
Tofflemire Retainer
| components (4)
Head
-U-shaped, has three guides or slots
for the position of the band
Locking Vise
-sliding body that holds the band
Long Knob
-changes the diameter of the loop
Short Knob
-locks the band in place within the sliding body
33
Head function on Tofflemire retainer
-U-shaped, has three guides or slots
| for the position of the band
34
Locking vise tofflemire retainer
-sliding body that holds the band
35
Long knob of tofflemire retainer
-changes the diameter of the loop
36
Short knob of tofflemeir
-locks the band in place within the sliding body
37
Tofflemire Matrix Bands
| • Uses and Purposes
• To restore a proximal surface or surfaces of teeth (Primarily for Class II Restorations)
Aid development of proper contact
Aid development of proper contour
Confine restorative material
Reduce amount of excess restorative material
• Protect teeth adjacent to tooth being prepared
band adjacent teeth
38
Matrix Bands
• Desirable Properties
(6)
* Easy to apply and remove, convenient
* Extend below gingival margins of preparation
* Extend above the marginal ridge height
* Resist deformation (rigidity) during material placement
* Ability to be contoured
* Versatility (size/shape)
39
• Note: May burnish the contact area with a burnisher after placement to help obtain proper contact
.
40
Matrix Bands
| • What’s with the bumps?
```
There are different band sizes,
shapes and thickness depending on application
-Universal bands
-MOD band
-Pediatric bands
```
41
3 types of matrix bands
- Universal bands
- MOD band
- Pediatric bands
42
The band arch of the matrix band goes towards
the O
43
The band arch of the matrix band does NOT go towards the? Hence the open end is where?
NOT apical
Open end is supposed to be apical
44
The orientation of the matrix band in the retainer is the same for which two quadrants (use Upper right as reference)
The orientation of the matrix band in the retainer is the same for the Maxillary (Upper) Right and Mandibular (Lower) Left quadrant.
45
Orientation of matrix band is the same for the Maxillary (Upper) Left and _______
Mandibular (Lower)Right quadrant.
46
Tofflemire Placement - Summary
• Band to Retainer Relationship-Narrow end of loop towards????
Narrow end of the loop that is formed should be toward the
| neck of the tooth (gingival aspect)
47
Matrix band System to Tooth Relationship
| ---The band is Oriented so the retainer is on the ______ side of the teeth
Buccal
| **sometimes this will not work so do L
48
The band of the retainer is placed on the B unless what
missing buccal tooth structure = no support
USE L
49
Slot (opening) of retainer should be toward the _____ of the tooth
Why?
Facilitates removal
Slot (opening) of retainer should be toward the neck of the
tooth (gingival aspect)
50
Wedges: Uses and Purpose
Helps compress matrix band against the tooth structure to
| create a tighter seal
51
Why do we use wedges to help compress matrix band
| against the tooth structure (2)
to create a tighter seal and prevent gingival overhangs
52
Wedge should compensate for thickness of
matrix band
53
Material types of wedges (2)
Wood and plastic
54
Types of plastic wedges (3)
* Anatomic
* Fender
* Others
55
Anatomic wedges
Triangle on one side and square on the other-built in contous
56
Type of wood used for matrix wedges?
Most made of sycamore
| wood
57
Con of plastic wedges vs wood
```
• Most made of sycamore
wood
• When they get wet, they
expand and conform to
the interproximal area
• Plastic wedges cannot
do this
```
58
Pro of wood wedges
```
• Most made of sycamore
wood
• When they get wet, they
expand and conform to
the interproximal area
```
59
How do plastic wedges compensate for not expanding like wood ones
conform to tooth
60
Fender
Separates tooth being worked on from adjacent
61
Fender has built in what
Fin of Silver matrix
62
Why we got rid of fenders
Sharp-they cut people
63
Wedge function considering gingival tissue (2-3)
Retraction of the gingival tissue
• Occupying space in the gingival
embrasure
• Sealing the seat
64
A wedge placed in the wrong place or wrong size
A wedge placed in the wrong position (too occlusally) or the wrong
sized wedge (too large) can hinder the development of a physiologi
contact area
65
A wedge placed in the wrong position (too ______) or the wrong
sized wedge (too ____) can hinder the development of a physiologi
contact area
O
large
66
Wedges can be placed on which side of tooth
B or L
67
When a matrix band is used on the buccal, the buccal area is difficult to access due to
the retainer
Therefore, you may have to place the wedge from the
lingual
68
used to place wedges
• Place wedges with your cotton forceps or
| hemostat
69
Amalgam Condensation Overview
Goals (3)
1. Compact the alloy
• Increase density
• Eliminate voids
2. Adaptation to the preparation walls and internal line angles/point angles
3. Reduce excess mercury
• Forces any excess liquid to the surface, which will later be removed (during carving)
70
Compacting amalgam does what (3)
Increase density
Eliminate voids
Reduce excess mercury
-Forces any excess liquid to the surface, which will later be removed (during carving)
71
When choosing a condenser, the face of the nib should ____
fit into all
| areas of the preparation
72
Condensation pressure and the relation to the size of the nib
* Directly related to the load applied
* Indirectly related to the area of the nib
***Thus smaller nibs produce more Force (smaller S.A)
73
Condensation force used on amalgam
Condensation force:
• Ideally 6-10lbs of force
(10lbs of force with a 2mm diameter condenser = 2000 psi)
• Vertical & lateral condensation is required
74
(10lbs of force with a 2mm diameter condenser = ____ psi
2000psi
75
Directions of condensation on class 2
Vertical and horizontal!!!`
76
The critical factor in placement technique for amalgam prep (especially class II)
Condensing
77
Condensation: Technique
| 3
Condensation: Technique 1. Should be orderly and overlapping
• Add incrementally • Generally, use smaller condenser first (NOTE: Larger will be used as
preparation becomes more filled) • Deepest part of preparation first!
2. Overfilling / Overpacking
• Assures Hg rich layer will be removed
• Aids in closed margins 3. Time
• Too long = increased voids
• 1 minute beyond manufacturer’s recommendation results in >30% increase
in residual Hg
78
Goal of amalgam carving
Reproduce anatomy that results in proper form & function
79
How to prevent flash
SHARP INSTRUMENT
80
Flash
Flash is an extension of the restorative material beyond the preparation
margins
• Thin & brittle = prone to fracture
81
When should carving be initiated?
Carving should be initiated before the amalgam has reached its initial set
82
Pre-check what before preparation for amalgam
Occlusion
83
Before you carve amalgam you do what
burnish-to remove overpack and approach margins
84
Anatomy to consider on tooth when carving
Think grooves, cuspal incline, ridges, fossa
85
When carving amalgam-if the grooves are too deep (3)
Thin amalgam = prone to fracture
Potential for exposure of preparation walls
Difficult to finish (or polish when necessary)
86
Use what to check occlusion? (product)
accufilm
87
Use accufilm with what for accuracy
accufilm ribbon
88
Over carving in a amalgam prep can lead to what
Over-carving may lead to an under-contour having a poor effect on soft
tissues (buccal, lingual, proximals)
89
Check occlusal contacts in which 2 directions
Check occlusal contacts in centric
| • Check occlusal contact in lateral excursions
90
Post prep---Instruct patients to avoid chewing _____ or _____ foods on new restorations for the
first____hrs (chew on other side) to allow
full set of amalgam
hard or chewy foods for 24 hours
91
Sensitivity to hot or cold sometimes
occurs. (If symptoms last longer than ______ or are severe, they should call your
office. )
2 weeks
92
Contour marginal ridge on amalgam with what on class 2 with band
explorer
93
First thing to do on amalgam carving of class II with band
get embrasure with band on
94
First area to work on in a class II prep once the matrix band is removed
• Check for overhangs
| first!
95
when to check for overhang in class II amalgam prep
First thing after removing band while material is more soft!
96
Detach amalgam from matrix band using the ______
| • This will also help to shape the occlusal embrasure
tip of the explorer
97
If only one proximal is being restored, remove the ____ side first -> then the ___ -> then the ___
opposite
wedge
side being restored
98
Wedge should be removed with
hemostat or cotton pliers
99
Matrix band should be removed how?
Why?
Matrix band should be removed vertically, but at 45 degrees
| • Help maintain contact
100
Potential Problems During Matrix Band Removal
• Fracture of the restoration
• If the marginal ridge fractures below the cavosurface of the preparation, the
restoration must be removed • Replace matrix system & wedge • Re-restore the preparation
