Midterm 1

Question 1

how is it possible for adhesive resin to bond high noble indirect restorations?

Answer 1

Adhesive resin cements work on 4-META technology so you can use it to bond high noble indirect restorations as long as you tin plate the intaglio surface

Question 2

what type of crown should you do with a cast post and core, and why?

Answer 2

• PFM
• you wouldn’t want to use something like zirconia because you’d get show-through from the CPC

Question 3

what is the lingual axial reduction for an anterior PFM preparation for metal? what about porcelain?

Answer 3

it is the same for both: 0.5-1.0

*lingual axial reduction is not the same as lingual concavity reduction

Question 4

what are the areas of importance that you should inspect for detail and accuracy when checking your stone models for crown and bridge?

Answer 4

• prepared tooth/teeth
• adjacent tooth/teeth, especially proximal surfaces
• occlusion
• *you should also check these when inspecting your impression*

Question 5

what type of margin is used for a cast post and core? what is the purpose of the cast post and core margin?

Answer 5

• bevel margin
• serves as another ferrule to resist root fracture
• making the bevel margin isn’t always possible

Question 6

For an anterior PFM crown, what is the lingual concavity reduction for metal and porcelain?

Answer 6

• metal lingual - 0.5-1.0mm
• porcelain lingual - 1.0-1.5mm

Question 7

Placement of the keyway for a cast post and core is lingual. Why?

Answer 7

• Keeping it lingual can help prevent fracture
• You have more tooth structures to the lingual
• It will also prevent the temporary from appearing dark

Question 8

when using triple function articulators, the set should be ___ when the model is poured up

Answer 8

passive (tray can’t be torqued or twisted while stone is setting)

Question 9

when cutting the die from the cast, why is it important to keep the cuts parallel?

Answer 9

So you can put the die back in easily – otherwise you’d have to take off the other pieces

Question 10

What clinical situations require you to take a full arch impression as opposed to a dual arch impression?

Answer 10

• 2^nd molar
• 3 or more teeth
• canines

Question 11

Is it advised to enlarge the canal to create a bigger diameter post to strengthen the restoration?

Answer 11

no, never

Question 12

what is an advantage and disadvantage of having a large base on your die?

Answer 12

• advantage: easier to hold when you are trimming it
• disadvantage: you will be forced to trim perpendicular to the axis of the preparation at times

Question 13

after trimming the die, what are the next steps up to the point of the wax-up?

Answer 13

• apply 2 coats of die sealer; use compressed air to thin it
• apply die relief; first coat applied 2-3mm from margins; second coat completely covers first coat and is applied 1-2mm of margins (should NOT touch the margins)
• begin wax-up

Question 14

T or F:

when trimming the triple tray impression to fit the articulator, opposing sides must be parallel

Answer 14

false

they can be somewhat divergent if needed

Question 15

when pouring up the FGC stone model for the articulator, which arch should be poured up first?

Answer 15

the arch with the die

Question 16

If you have a high noble casting (75% gold), can you bond that into place?

Answer 16

You can if you tin plate it; you have to bond it with adhesive resin cement

Question 17

When shaping the die apical to the margin, you want to shape it so that it will maintain ___

Answer 17

axial wall contours

you are less likely to abrade the margins if you do this

Question 18

what is the difference between a thin and thick biotype?

Answer 18

thin biotypes have thinner gingival thickness and are more susceptible to gingival recession, whereas thick biotypes have thicker gingiva and are usually not a problem

Question 19

what stone type is used when pouring up the FGC stone model for the articulator, and what is it important to remember to do with the articulator before pouring?

Answer 19

• type IV
• you need to remember to spray silicone separator into the appropriate index of the articulator

Question 20

is the bevel margin on a cast post and core preparation critical?

Answer 20

no - it is ideal, but you can still do a CPC if you can’t get the bevel margin

Question 21

when taking an impression for a cast post and core, how should the impression material be injected?

Answer 21

• inject around the head of the blue pastic analog post, starting in the anti-rotational keyway
• move to margins of tooth preparation
• add balance of syringe material all around the area of the tooth
• insert the impression tray

Question 22

what type of restoration should be strongly considered on a tooth with more than 1/2 of coronal tooth structure missing?

Answer 22

cast post and core

Question 23

which of the following anterior PFM framework designs is/are unfavorable?

• opposing tooth contacts porcelain
• opposing tooth contacts the porcelain/metal junction
• opposing tooth contacts metal

Answer 23

opposing tooth contacts the porcelain/metal junction

Question 24

what should you use to finalize the marginal area of your die when trimming?

Answer 24

25 blade in a red handle

Question 25

why is the wingless preparation the preferred design for an anterior PFM crown?

Answer 25

* better esthetics * slightly less retentive * easier

Question 26

why are cast post and cores made with a tapered post?

Answer 26

* because you put a taper on the axial walls of the preparation, and so you want to mirror that * it is an indirect restoration and it will be inserted into the tooth, so the taper helps it go in easier because it should match the canal walls

Question 27

what are some important considerations in cementing a final cast post and core restoration?

Answer 27

* post and crown should be cemented simultaneously with a chemical cure, self-adhesive cement such as C&B metabond or panavia * vertical pressure should be applied during cementation, and patient should NOT bite on the restoration during the set * remove excess cement during the rubbery stage (don't cause gingival bleeding, and don't wait until cement is set before removing it)

Question 28

When trimming your die, what is the dangerous direction of the cutting edge to rotate? how can this be avoided?

Answer 28

* Perpendicular to the axis of the die or parallel to the margin * Instead, you want the long axis of your cutting instrument to be parallel to the axis of the preparation

Question 29

when taking an alginate impression, you should insert the tray from from front to back or back ro front?

Answer 29

front to back

Question 30

Why do we start cutting the cast apart from the base of the index side rather than the die side (aka you go apical to occlusal)?

Answer 30

Less chance of having that saw blade come up against the margin

Question 31

If you get anterior gingival recession in someone with a high smile line, is that problematic?

Answer 31

yes

Question 32

what should you do to the canal before taking an impression for a cast post and core?

Answer 32

dry it with a paper point

Question 33

what is a diagnostic tooth preparation?

Answer 33

done before the actual preparation clinically; it gives the operator a preview of what’s coming; it’s kind of like a trial run

Question 34

in the lock-and-key preparation technique, where should the anti-rotational keyway be placed? why?

Answer 34

* on the lingual/palatal aspect * it could cause a fracture if it's not on the lingual * it's more compatible with the forces that are placed on the teeth * you tend to have more tooth structure on the lingual/palatal

Question 35

why is it important to extend stone toward the distal when pouring up the stone model of the cast post and core?

Answer 35

to create an index, allowing the arches to fit together like a puzzle piece

Question 36

what are the reduction measurements for a FGC?

Answer 36

* occlusal reduction/clearance * functional cusp: 1.5-2.0mm * non-functional cusp: 1.0-1.5mm * functional cusp bevel: 1.5-2.0mm * axial reduction: 0.5-1.0mm at margin * margin type: chamfer * non-functional cusp bevel: 0.3-0.7mm wide * softened acute line and point angles

Question 37

What happens if the analog post gets hit when the patient bites down?

Answer 37

just trim it

Question 38

for the midterm, what is the range for incisal reduction for an anterior PFM preparation?

Answer 38

2-3mm

Question 39

why don't you need as much lingual reduction for an anterior PFM?

Answer 39

Because there is usually metal on the lingual (in other words, you don't need as much porcelain) * lingual concavity reduction for metal is 0.5-1.0mm * lingual concavity reduction for porcelain is 1.0-1.5mm

Question 40

T or F: maxillary keyways should be palatal, and mandibular keyways should be buccal

Answer 40

false they should both be palatal/lingual

Question 41

how should PVS impressions be removed from the patient's mouth once set?

Answer 41

* opposing arch comes off first * remove impression from the prepared tooth arch by _pulling entire impression out parallel with the post's line of draw to avoid torquing or tipping_

Question 42

when cementing a temporary crown, why is it important to only apply cement to the base of the acrylic and not on the post?

Answer 42

cause you'll cement the gat dang post to the teeth! then how are ya gonna get it out? SMH.

Question 43

T or F: You can get a more consistent bite registration component with a triple bite tray (aka dual arch impression) rather than two separate full arch impressions

Answer 43

true

Question 44

if a tooth is badly broken down, what type of restoration will hold up best?

Answer 44

cast post and core

Question 45

when pouring up the stone model of the cast post and core, which arch should be poured first?

Answer 45

the one with the prepared tooth

Question 46

can zirconia crowns be used with any preparation design?

Answer 46

yes, even though we have an ideal prep

Question 47

how should vacuum mixers be stored?

Answer 47

with water inside

Question 48

In a posterior PFM preparation, what is the axial reduction? where should it be heavier?

Answer 48

* 1.2-1.7mm * heavier on buccal transitioning to lighter on the lingual

Question 49

when fabricating a temporary for a cast post and core, why is it important that the metal post is toward the lingual/palatal?

Answer 49

if it is too facial, it can show through and give the temporary and darker appearance

Question 50

when doing an impression pour up for a cast post and core, how much stone and how much water should you use? what about when pouring up the FGC stone model for the articulator?

Answer 50

* 100g of stone and 21ml of water for CPC (single arch) * 100g of stone and 20ml of water for FGC (two arches, otherwise it's half for a single arch)

Question 51

what cement should be used on a temporary?

Answer 51

polycarboxylate cement