class II amalgam

Question 1

What is a direct restorative material?

Answer 1

Classifies as plastic- readily deformable when first mixed and placed into prepared cavity
Modelled into appropriate shape
Eg amalgam

Question 2

What is an indirect restorative material?

Answer 2

Usually formed in lab and finished restorations cemented into place
Eg full gold crown

Question 3

How can you classify radiographic caries extent?

Answer 3

E1- outer half enamel 
E2– inner half enamel
D1- outer third dentinal
D2- middle third dentinal
D3- inner third dentinal

Question 4

What is the isthmus?

Answer 4

Narrowest part across occlusal table
Weak point
Must have sufficient depth

Question 5

What is the ideal cavity design?

Answer 5

Size determined by caries extent
Retention of 2-5 degree divergence of walls towards floor
Margins should extend just out of contact area unless caries says otherwise

May consider tunnel prep- more minimal to target caries

Question 6

What should cavity margins be like?

Answer 6

Cavosurface angle- 90-100 degrees
Less= enamel rods fracture under occlusal load
More= amalgam thinned at margins and fracture; voids

Question 7

What are the different matrix systems?

Answer 7

Siqveland- 2 widths, removable, disposable band and autoclavable holder

Tofflemire- similar to siqveland

Automatrix- no holder, has winder and can be snipped, 3 widths and different thickness, good for multiple fillings

Pro matrix- 2 widths, fully disposable, metal and clear

V ring matrix- palodent, sectional, band disposable, pin tweezers, v ring and forceps autoclavable