Tooth Preparations

Question 1

According to the lab handout, what are the anterior PFM specifications for incisal reduction?

Answer 1

1.5 -2 mm parallel to original edge (or slanting slightly lingually)

Question 2

According to the lab handout, what are the anterior PFM specifications for proximal reduction?

Answer 2

Walls converge 3-4 deg, and minimum 3mm long, adjacent tooth cleared by 0.5 mm gingivally

Question 3

According to the lab handout, what are the anterior PFM specifications for lingual reduction?

Answer 3

0. 7-0.8mm clearance on canine

0. 7mm on incisor

Question 4

According to the lab handout, what are the anterior PFM specifications for cingulum reduction?

Answer 4

converges incisally 6-8 deg, 3 mm long

Question 5

According to the lab handout, what are the anterior PFM specifications for facial reduction?

Answer 5

2 planes

Question 6

According to the lab handout, what are the anterior PFM specifications for the margins?

Answer 6

F shoulder – 1.0 mm, 90-110 deg internal angle

Facial shoulder to lingual chamfer transition 1.0 mm lingual to intitial proximal contact

Question 7

Where should finish lines be optimally placed?

Answer 7

On enamel away from sulcus

Question 8

What margin design is indicated if margin must extend apically onto the root surface?

Answer 8

Chamfer

Question 9

Where will furcal flutes be closer to the CEJ: mandible or maxilla molars?

Answer 9

Mandibular molars ( CEJ closer to mandibular furcation)

Question 10

What is the benefit of incorporating furcation concavities into the crown prep?

Answer 10

Decrease plaque retention areas

Question 11

When a root is removed from a tooth, irrespective of what it does to the crown, what effect does it have on the tooth?

Answer 11

Effects the overall emergence profile of the crown based on which root is removed from the molar