Class 2 preparation for amalgam

How does caries start?

• demineralization

• remineralization

• discolouration

• fracture

How deep should you cut the occlusal portion of the class 2 prep on the typodont?

• 1.5 - 2.0 mm

• 2.0 - 2.5 mm

• 1.0 - 1.5 mm

• 2.5 - 3.0 mm

Resistance form is the shape of the cavity prep to prevent

• fracture of the restoration

• fracture of the tooth

• lateral displacement of the restoration

• vertical displacement of the restoration

How is amalgam retained in the tooth?

• mechanical lock

• convergence

• divergence

• single bond

What is retention form?

• Form/design in the prep that will prevent the restoration from dislodgement in a vertical direction

• Form/design in the prep that will prevent the restoration from dislodgement in a horizontal direction

• Form/design in the prep that will prevent the restoration from dislodgement in a mesial direction

• Form/design in the prep that will prevent the restoration from dislodgement in a distal direction

Convenience form is__________________________________

• enough space to allow inspection

• enough space to allow manipulation of instruments

• enough space for cavity toilet

• enough space for occlusion

Width of the isthmus in a class 2 cavity prep should be

• < 1.5 mm

• <1.75 mm

• < 2.0 mm

• < 2.5 mm

The retention grove is placed in the class 2 prep_____________

• from the gingival floor to the height of the pulpal floor

• from the gingival floor to the cavosurgace margin

• from the gingival floor to the axial wall

• from the gingival floor to the proximal wall

Pulpoaxial line angle should be rounded or beveled, why?

• To take the stress off the restoration

• To prevent fracture of the restoration

• To allow for swift condensation

• To allow for convenience form

What are the types of class 2 cavities?

• Single surface - proximal surface only

• Two surfaces involving the occlusal - Compound

• Three surfaces involving the occlusal - Complex

• Three surfaces involving the occlusal, buccal and lingual