Principles of tooth prep III

Question 1

Cements are strongest under _ forces

Answer 1

compressive

Question 2

Cements are stronger under (shear/tensil) stresses

Answer 2

shear

Question 3

Cements are weakest under what forces

Answer 3

tensile

Question 4

What determines whether the cement will be under compressive or tensile forces

Answer 4

the prep

Question 5

What are the three most common complications for a single crown

Answer 5

• Need for endo
• Porcelain fracture
• Loss of retention

Question 6

Cement is placed under tensile forces when the TOC is (high/low)

Answer 6

high

Question 7

Decreased taper subjects the cement to what forces

Answer 7

shear

Question 8

Surface area pertains to (occlusal surface/axial walls)

Answer 8

axial walls

Question 9

increased SA –> _ retention

Answer 9

increased

Question 10

Partial coverage restorations must be bonded…

Answer 10

adhesively (due to less retention)

Question 11

Increase FL width leads to (increase/decreased) resistance and why

Answer 11

decreased… larger arch of rotation

Question 12

Increase FL width leads to (increase/decreased) retention

Answer 12

increase

Question 13

To increase reisstance form you decide to decrease the TOC. This should be done where on the axial wall

Answer 13

apical 1.5 mm (Cervical portion of the walls)

Question 14

T/F Prepping the occlusal form parallel to the original inclines has a significant impact on resistance

Answer 14

f- not very significant

Question 15

The BEST way to increase resistance for of a tooth is to

Answer 15

decrease TOC in the cervical portion (more effective than grooves/boxes)

Question 16

What are the guidelines for proper placement of axillary grooves and boxes

Answer 16

• Must draw with remainder of prep (have POI)
• Be parallel to each other
• Be 1mm coronal to the margin

Question 17

When are BL grooves used

Answer 17

crowns on abutment teeth for RPD

Question 18

The BL groove should be placed on the wall that is (least/most) tapered

Answer 18

least

Question 19

Best POI for a crown follows

Answer 19

the long axes of the adjacent teeth

Question 20

(monocular/binocular) vision can make a prep that is undercut look acceptable

Answer 20

binocular…. thus monocular should be the method used to check a prep

Question 21

How can you check the POI of a bridge with a mirror

Answer 21

Place the mirror over one prep til the entire finish line can be seen then move the the next prep if the mirror angulation changes then you don’t have a POI