Class 1 Prep Quiz 3

Question 1

marginal ridge width of class 1

Answer 1

2mm molars

1.6 mm premolars

Question 2

Resistance Form

Answer 2

flat pulpal floor, rounded internal line angles, sufficient pulpal depth, isthmus width, DIVERGENT M and D walls, enamel margins 90 degrees to external tooth surface, preserve marginal ridges

Question 3

isthmus width

Answer 3

no wider than 1/4 of intercuspal width, BUT at least 1mm wide for convenience form b/c smallest condenser is 1mm

Question 4

Divergent or convergent M and D walls

Answer 4

Divergent

Question 5

Retention form for gypsum on class 1

Answer 5

convergent B and lingual walls, enamel and dentin bonding agents (resin)

Question 6

internal line angles of class 1

Answer 6

rounded

Question 7

enamel margins angle to external tooth surface

Answer 7

90

Question 8

convenience form of class 1 basic

Answer 8

isthmus wide enough for amalgam condensation, get condenser that is 1mm in

Question 9

cusps of teeth (mand molars)

Answer 9

1st molar 5 2nd 4

Question 10

lingual angulation

Answer 10

angle bur parallel to long axis of tooth, evens pulpal floor, mand first premolar exaggerated bc pulpal horn

Question 11

General principles of amalgam prep

Answer 11

1. do not terminate margins on cusp tips
2. all weakened/unsupported enamel should be removed
3. preserve cusp/marginal ridge strength
4. do not extend to unaffected fissures
5. preserve cusp inclines
6. smooth curves, no sharp edges
7. pulpal depth uniform 1.5mm (.5mm from DEJ)-bulk for strength
8. 90 degree cavosurface margin

Question 12

pulpal floor should be _____ to ______ in order to

Answer 12

perpendicular to long axis of the tooth protects the pulp

Question 13

F-L the prep should ___ so it aligns with ___

Answer 13

converge to align with enamel rods

Question 14

M-D the prep should ___ so it aligns with ___

Answer 14

diverge to align with enamel rods

Question 15

The phenomenon that teeth are not perpendicular to the ground is called

Answer 15

curve of Wilson or lingual inclination

Question 16

has exaggerated angle/most prominent inclination which affects the prep

Answer 16

mandibular 1st premolars-due to pulpal horn

Question 17

Class I amalgam prep

Answer 17

caries on the pits and fissures, occlusal, buccal and lingual of post and maybe the lingual of ant teeth

Question 18

Basic Outline Form principles

Answer 18

1. extend around cusps to conserve structure and pulp
2. keep facial and lingual extensions conservative
3. place margins on smooth, sound structure, extending only to cariously involved fissures
4. preserve marginal ridge to prevent fracture

Question 19

Ideal margin widths

Answer 19

1.6mm for premolars and 2mm for molars

Question 20

isthmus width

Answer 20

no wider than 1/4 intercuspal width but a minimum of 1mm for convenience form (fit amalgam condenser)

Question 21

convenience form criteria

Answer 21

isthmus of 1mm for amalgam condenser fit