Operative Part 2 Flashcards

1
Q

What is a GV black class 6 classification?

A

Just incisal edge of anterior or cusp tip of posterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is friable enamel?

A

Enamel that is hypomineralized. Not only is it weaker, Bonding agent is not as effective in friable enamel.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Ideally, cavosurface margins should be > or = to ___ degrees

A

90

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

A cutting bur is likely to have ___ blades while a finishing bur is likely to have ___ blades

A

6

12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

You have to lose about __% of enamel mineral before you can see a radiolucency.

A

25%

In other words, the actual disease is 25% worse than it appears on an X-ray

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Define dental ferrule

A

A band that encircles the external dimension of tooth structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the minimum ferrule length when restoring a root filled maxillary central incisor with a post and core retained crown?

A

1.5mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

True or false… ferrule refers to the step-like feature on a tooth for a crown

A

False.. ferrule refers to the portion of the crown that touches the axial walls of the tooth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What comprises the biological width?

A

1mm connective tissue attachment

1mm epithelial attachment

1 + 1 = 2mm biological width

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

It is generally safe to place crown margins __ subgingival without impinging on the biological width

A

0.5mm (AKA there needs to be 2.5mm from crest of bone to crown margin at minimum)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are two methods to prepare a tooth for a crown that would otherwise impinge on the biological width?

A

Crown lengthening (bone down)

Orthodontic extrusion (tooth up)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Name two different types of chemicals used for external bleaching

A

Hydrogen peroxide

Carbamide peroxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the differences between hydrogen peroxide and carbamide peroxide?

A

Hydrogen peroxide - breaks down faster (30-60 minutes)

Carbamide peroxide - remains active longer (2-6 hours), increased shelf life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

For every 10% of carbamide it forms about ___% of hydrogen peroxide. In other words, its a __:___ ratio

A

3

1:3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

True or false… there is no difference in sensitivity, rebound/regression, and results between hydrogen peroxide and carbamide peroxide

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What percent of hydrogen peroxide is used for in-office visits only?

A

30-40%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are some risks of external bleaching?

A

Gingival irritation

May worsen tooth sensitivity (reversible)

Will not change the color of fillings and crowns

Will not be effective against intrinsic stains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

True or false… class 1 restorations include: lingual of maxillary incisors, occlusal of posteriors, and occlusal 2/3 of F/L of molars

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

In a class 1 preparation, the initial punch cut should be made where?

A

Most carious pit

If its a tie, start distal and go mesial for best visibility

20
Q

When doing the initial prep for a class 1 restoration, you should cut ___mm inside the DEJ and…

A

2

Do not go any deeper even if there are caries. Then extend laterally in all directions without going deeper, until you reach sound tooth structure (AKA bounds of the disease)

21
Q

True or false… for composite restorations, the initial pulpal floor should follow the rise and fall of the DEJ

A

True

22
Q

Ideally, the isthmus of a class 1 preparation should be no more than ___mm, or ___ the intercuspal distance so that…

A

1

1/4

It doesn’t decrease tooth strength

23
Q

How are convergent walls helpful for composite restorations?

A

Protect adhesive interface

Not technically retentive feature for composite

24
Q

Define resistance form in regards to a class 1 cavity prep

A

Pulpal floor should always be perpendicular to occlusal forces

Rounded internal line angles

No unsupported enamel (cavosurface margins > 90 degrees

25
Q

True or false… retention form is unnecessary for composite class 1 restorations

A

True

26
Q

It is important to keep about ___mm of marginal ridge intact for integrity

A

1.6mm

27
Q

When preparing the marginal ridge, there should be slight [convergent/divergent] tilting bur at ___ degrees in order to compensate for enamel rod orientation

A

Divergent

10

28
Q

You should use ___% H3P04 for __-__ seconds. Fill in preparation and go ___ over cavosurface margins.

A

35%

15-30

0.5mm

29
Q

Name three functions of acid etch

A

Removes smear layer from enamel and dentin

Selectively removes end of enamel rods (micro-roughness)

Selectively removes mineral of dentin to expose collagen fibrils

30
Q

5th generation (total etch) is ___ and ___

A

Priming = solvent, small hydrophilic monomers

Bonding = hydrophobic monomers, filler, polymerization agents

(Primer and adhesive)

31
Q

After you apply primer/adhesive you should __ for __s. Then repeat to fully infiltrate exposed collagen. Then light cure for 10s

A

Air dry

5s

32
Q

Amalgam requires __-__mm of bulk

A

1.5-2mm

33
Q

What is the difference between primary and secondary retention in amalgam preps?

A

Primary retention = occlusal convergence

Secondary retention = retention groves with 1/4 round or 169L buryou

34
Q

True or false… you must desensitize the pulp with amalgam restorations. Why?

A

True

Amalgam is a conducting metal (temperature changes can cause rapid dentinal fluid movement)

Micro-gap along margins takes time to self-seal (perforation into gap can also cause rapid dentinal fluid movement)

35
Q

What can you densensitize pulp with? What is this material made of?

A

GLUMA or G5

5% gluteraldehyde - fixative, plugs tubules

35% HEMA = monomer

Water

Rub into preparation for 60s and rinse for 10s

36
Q

When condensing amalgam, you want to overfill by __mm in order to… (2 things)

A

1mm

Eliminates excess Hg

Ensures margins are completely covered

37
Q

Why is secondary anatomy contraindicated in amalgam restorations?

A

Grooves may thin amalgam and invite chipping

38
Q

What are some post op instructions you should give your patient after an amalgam restoration?

A

Chew on the other side until at least tomorrow so it sets fully

Tell them they should expect to feel numb for the next few hours, so do not bite cheek

Expect to feel sore for the next while, take ibuprofen PRN

39
Q

What are some potential problems with a deep apical box in a class 2 composite prep?

A

Hard to isolate

Hard to properly matrix band and wedge

Hard to reach with curing light

Gingival wall can eventually run out of peripheral enamel and bonding to dentin is not as predictable

40
Q

What is the lamination defect?

A

Packing composite can result in voids that can be filled with stain

41
Q

What is the best design for class 2 box form that allows conservation of cusps, 90 degree exit angles?

A

Reverse S

42
Q

How much clearance should be evident in a class 2 box form?

A

0.25-0.5mm on facial, lingual, and gingival walls

43
Q

The matrix for a class 2 restoration must be __mm(s) higher and lower from exits of prep

A

1mm

44
Q

What type of wedge should be used for a normal depth class 2? What type wedge for a deep prep?

A

Round wedge for normal depth

Triangular/anatomic wedge for deep prep near root surface

45
Q

What is the purpose of dovetails in an amalgam class 2 prep?

A

Prevents proximal displacement

46
Q

True or false… ZnO Eugenol interferes with composite

A

True

47
Q

What is the difference between vitribond and dycal?

A

Vitrebond (RMGI) - acid-base; carboxyl group in PAA preferentially binds with calcium in hydroxyapatite (calcium chelation) to form a unique chemical bond

Dycal (CaOH2) - paste; irritates pulp with 11.7 pH to stimulate differentiation of mesenchymal cells to secondary odontoblasts to make tertiary dentin (best if super close to pulp. However it must be covered with vitrebond because it does dissolve)