class I prep

Question 1

3 cavity prep fundamentals

Answer 1

1. defect/caries remove and traumatic injury repaired
2. all unsupported enamel removed (usually) ** wall angle plays role in this
3. remaining tooth left as strong as possible

Question 2

cavity prep

Answer 2

mechanical alteration of tooth to receive restorative material that will return tooth to proper anatomical form, fxn and esthetics

Question 3

classfication of class I

Answer 3

• anything originating in structural defects
• ususally posterior occlusal
• also palatal pits of anteriors
• also occusal 2/3 of B adn L surfaces of posteriors

Question 4

caries progressionq

Answer 4

accumulation of cariogenic organisms in pits/fissures creates the caries —- progress from surface to DEJ

spread rapidly at DEJ, laterally along jxn

rapid spread in dentin

Question 5

isthmus width, class I

Answer 5

just wide enough to accept instrumentation

Question 6

marginal walls of class I

Answer 6

(so this is the long central part of prep – talking about its edges at M adn D surface)

• at least 1/2 distance from (either M or D) pit to crest of marginal ridge; wall is parallel to marginal ridge
• PM at least 1.6mm from prep to proximal surface
• molar at least 2.0mm

^^closer to edge than this, you drop it to a box

Question 7

resistance form of class I

Answer 7

M adn D diverge occlusally

B adn L converge

Question 8

cavosurface angle

Answer 8

90-100 degrees

this means amalgam margin is 80-90 degrees

Question 9

amalgam jxn with tooth, thickness

Answer 9

• 90 degree jxn with tooth

- 1.5mm thick for resistance

Question 10

what line angles are less than 90 degrees?

Answer 10

bucco pulpal line angles

lingual pulpal line angles

Question 11

how do you remove deep caries

Answer 11

large, slow speed bur

Question 12

3 general principles for outline form for calss 2

Answer 12

1. all unsup.en gone
2. all caries gone
3. all margins in position to allow restoaration to be placed

Question 13

when can you leave unsup.en

Answer 13

when it is on an area of low stress, such as anterior tooth (esthetic concerns) and NOT FRIABLE and bonded restoration used

Question 14

why does the horizontal floor of box resist occlusal load

Answer 14

because it is perpindicular to forces of chewing, which are directed along long axis of tooth

Question 15

slot prep

Answer 15

box only prep; occlusal surface not faulty; use proximal retention grooves, more conservative because you remove less tooth