Amalgam

Question 1

Factors contributing to resistance form of amalgam

Answer 1

1- Flat pulpal floor
2- Sufficient depth
3- Minimal extension
4- 90º cavosurface margin
5- Wall parallel to enamel rods
6- Rounded internal preparation angles

Question 2

Indications of amalgam

Answer 2

Class I, II, V (where esthetic is not important/high caries risk)
Patient desire
Cost

Question 3

Contraindications of amalgam

Answer 3

Allergy
Esthetic area
Conservative design is better

Question 4

Factors contributing to retention form:

Answer 4

Primary retention: frictional retention, B-L wall convergence
Secondary retention: dovetail design

Question 5

Which tooth has a preparation design resembling “snake eyes”?

Answer 5

Mandibular 1st premolars

Question 6

Which bur can be used for initial amalgam cavity preparation?

Answer 6

245 (330L)/Elongated-pear
330/Pear

Question 7

In an amalgam cavity preparation, M-D walls should be:

Answer 7

Divergent

Question 8

The depth of the cavity should be:

Answer 8

1.5-2 mm

Question 9

Over-triturated amalgam:

Answer 9

Mix is warm, shiny wet and soft

Question 10

Under-triturated amalgam:

Answer 10

Mix will crumble due to weakness

Question 11

Properly triturated amalgam:

Answer 11

Good shiny mix; homogenous mass, adhering together

Question 12

How much should you overfill the amalgam cavity?

Answer 12

About 1 mm

Question 13

In the postcarve burnishing, the purpose is to:

Answer 13

Improve marginal integrity and smoothness (not shiny)

Question 14

In postcarve burnishing, which type of burnishers are used?

Answer 14

Small burnishers

Question 15

Finishing and polishing of amalgam is done at which time?

Answer 15

After 24 hours

Question 16

In maxillary molars, the outline of distal side of the oblique ridge is:

Answer 16

Round or oval

Question 17

In maxillary molars, the outline of the mesial side of the oblique ridge is:

Answer 17

Butterfly

Question 18

When should you extend the cavity preparation across a maxillary molar’s oblique ridge?

Answer 18

When it is undermined by caries
or
Less than 1.0 mm sound ridge structure remaining between M & D preparation

Question 19

The outline form of maxillary premolars is:

Answer 19

Butterfly or U-shaped

Question 20

For a mandibular 2nd premolar outline form, when should you not connect the mesial and distal pits?

Answer 20

• Presence of transverse ridge (adds strength)
• Absence of an occlusal fissure

Question 21

It is permissible to repair a defective portion of an existing amalgam restoration if:

Answer 21

the remaining portion of the original restoration retains adequate resistance and retention form.

Question 22

When caries are present in the proximal aspect without involving the marginal ridge, a proposed cavity design is:

Answer 22

Slot preparation

Question 23

Components of a compound class II amalgam cavity:

Answer 23

• Occlusal portion
• Isthmus portion
• Proximal portion

Question 24

In an amalgam cavity, the isthmus portion should be _______ than the occlusal.

Answer 24

Wider

Question 25

Lines that are detected for proper freeing of contact; they describe the shape of the buccal and lingual walls of the proximal cavity at different situations of the contact area.

Answer 25

Ingrham’s lines

Question 26

In cases of open contact, Ingrham’s lines should be:

Answer 26

Straight

Question 27

The universal curve is used when:

Answer 27

Wide embrasures and broad contacts

Question 28

The revers curve is usually done in:

Answer 28

Buccal wall of class II

Question 29

Advantages of the reverse curve:

Answer 29

- Proper freeing of contact - Obtaining of 90° C.S.A. - Increase bulk of the restoration to prevent marginal ditching at the bucco-proximal area

Question 30

Plunging cusps should be recontoured during:

Answer 30

The initial clinical procedure

Question 31

In a cavity prep, enter the pit nearest the involved proximal surface with a:

Answer 31

Punch-cut

Question 32

Which structure is an important guide in the proximal class II preparation?

Answer 32

DEJ

Question 33

The initial procedure in preparation of the outline form is the isolation of the proximal enamel by doing the:

Answer 33

Proximal ditch cut

Question 34

The proximal ditch cut is extended:

Answer 34

Gingivally: - Just beyond the caries - Or the proximal contact (whichever is greater)

Question 35

Ideally, the extension of facial and lingual margins of a proximal box should be equal to _______ to provid:

Answer 35

It should be 0.2-0.3 mm from the adjacent tooth to provide clearance

Question 36

The axial wall is always placed in the dentin to obtain:

Answer 36

- Resistance & elasticity of dentin - Bulk of the restoration - Placement of retentive locks

Question 37

The axial wall should NEVER be:

Answer 37

Concave

Question 38

The gingival seat consists of:

Answer 38

2/3rd of dentin and 1/3rd of enamel

Question 39

To ensure that the faciolingual dimension at the gingival is greater than at the occlusal, the proximal ditch cut may be:

Answer 39

Diverged gingivally

Question 40

To protect the gingiva and the rubber dam when extending the gingival wall, what could be placed?

Answer 40

A wooden wedge

Question 41

The proximal retention locks could be placed using which burs?

Answer 41

169L bur or the ¼ bur

Question 42

Retentive locks are placed in:

Answer 42

Axiofacial and axiolingual line angles

Question 43

Proximal retention locks should terminate at:

Answer 43

Axiopulpal point angle

Question 44

Retention locks should be placed _____ inside the DEJ, regardless of the depth of the axial walls and axial line angles.

Answer 44

0.2 mm

Question 45

The four characteristics or determinants of proximal locks:

Answer 45

1- Position 2- Translation 3- Depth 4- Occlusogingival orientation

Question 46

What should connect the tooth & amalgam?

Answer 46

Butt joint

Question 47

The cavosurface bevel should be:

Answer 47

20º

Question 48

Beveling is not required when:

Answer 48

The gingival margin is gingival to the CEJ

Question 49

To prevent the microleakege of the amalgam restoration, what should be applied on all the preparation walls?

Answer 49

Varnishes

Question 50

To reduce the postoperative sensitivity, what could be placed?

Answer 50

GLUMA desensitizer

Question 51

Disinfection of the preparation walls can be done by:

Answer 51

Silver nitrate Phenol Ethyl alchol (short duration)

Question 52

Amalgam condensation should occur first in:

Answer 52

The proximal box(es), filling about 1 mm first

Question 53

Early removal of the matrix bands leads to an increased risk of:

Answer 53

Marginal ridge fracture

Question 54

What may be used to carefully define the occlusal embrasure?

Answer 54

An explorer or a small Hollenback carver

Question 55

From which direction should the matrix be removed?

Answer 55

Linguooccluasally or (faciooccluasally)