Lab 4: Class V

Question 1

extension balances these two needs

Answer 1

1. need to conserve tooth tissue

2. need to access and to remove defective tooth structure

Question 2

when preparing axial wall on Class V restoration, need to go…

Answer 2

1.5-1.75mm at occlusal wall

1-1.25mm at gingival wall

Question 3

why are there different axial depths between gingival/occlusal?

Answer 3

thinning of enamel

Question 4

optimal cavosurface angle for amalgam

Answer 4

90 degrees/butt joint

Question 5

gingival/occlusal wall ideas

Answer 5

smooth

Question 6

ideal location of retention groove

Answer 6

0.5 mm deep to DEJ in gingival wall, extending fully M-D

Question 7

when is occlusal retention groove needed?

Answer 7

only required when preparation is over-extended beyond height of contour

Question 8

angles between O, M, G, D walls rounded to prevent…

Answer 8

fracture, especially on cusps (for Class V)

Question 9

retainer that retracts Fa gingiva

Answer 9

212 retainer

Question 10

outline form of Class V

Answer 10

rounded trapezoidal

Question 11

extension of Class V

Answer 11

• occluso-gingivally
• M-D
• axial