Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Fixed Prosth 3rd year > L2 -Prep Design > Flashcards

L2 -Prep Design Flashcards

1
Q

implications of a flat occlusal surdace

A

may over shorten the preparation

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

turning point on reduction of number 8

A

over reduction

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

principle number wo of prep

A

preservation of the periodontium

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

biological width is..

A

dimension of space that the healthy gingival tissues occupy above the alveolar bone

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

evaluate the bio width with

A
  1. radiographs
  2. probing
  3. bone sounding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

biological width is..

A

dimension of space that the healthy gingival tissues occupy above the alveolar bone

normal is 2.0mm to 3.00

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

evaluate the bio width with

A
  1. radiographs
  2. probing
  3. bone sounding
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why important to not violate biological width

A

the attachment complex will be damanged

  • some distance of unpreparaed tooth structure should remain between the finished line and juncitonal epithelium and this distance is ideally 0.5mm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

why important to not violate biological width

A

the attachment complex will be damanged

  • some distance of unpreparaed tooth structure should remain between the finished line and juncitonal epithelium and this distance is ideally 0.5mm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

amunt of tooth structure that should remain between finish line and junctional epithelium

A

ideally .5mm

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

no difference in location of margins if supra and sub-gingival

*only when?

A
  1. in health of the gingiva
  2. in the change of sulcus depth
  3. in the gingval contour
  4. in plaque accumulaion

*when the crown margins are well fitted and well contoured

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

principle number 3 of prep

A

retention and resistance

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

retention stops from

A

up and down

- the quality inherent in the dental prosthesis acting to resist the forces of dislodgment along the path of placement

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

factors affecting retention form

A
  1. magnitude of dislodging forces: sticky foods, floss under connectors
  2. path of insertion
  3. geometry of tooth prep
  4. materials being cemented
  5. type of luting agent and film thickness of luting agent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

factors affecting retention form

A
  1. magnitude of dislodging forces: sticky foods, floss under connectors
  2. path of insertion
  3. geometry of tooth prep
  4. materials being cemented
  5. type of luting agent and film thickness of luting agent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

path of insertion

A

the specific direction in which a prosthesis is placed on the abutment teeth or dental implants

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

two dimensions of path of insertion

A
  1. facio-lingual

2. mesio-distal

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

Factors affecting the Taper

A

1.

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

average taper dentist achieve in preps

A

from 14.3 to 22.1

- annerstad, norlander

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

freedom of displacement affects?

A

retention and resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

freedom of displacement

A

associated with retention and resistance

*numbers of paths along which restoration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

one path of insertion allows for

A

better retention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

longer tooth implication

A

more SA - so more retention available

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

wider tooth?

A

more SA – more retention more area

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

resistance form

A

the features of a tooth prep that enhance the stability of a restoration and resist dislodgment along an axis other than the path of placement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

conclusion from

A

3mm of height for anterior and pre-molars

with a range of 10-20 degrees

4mm for molars and have a greater convergence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

T/F make sure you know the papers cited in this lecture

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

T/F make sure you know the papers cited in this lecture

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

number one failure of crowns

A

due to poor resistence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

if prep is narrow its effect on resistence?

A

increase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

narrow prep for resistance and retention

A

narrow – better resistance

narrow – worse retention

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

advantages of PFM

A
  1. long history of success

2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

limit of reduction use what material?

A
  1. PFM
  2. zirconia

both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

all ceramics need what reduction?

A

2 mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

if aesthetics are most importnat use?

A

all ceramic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

isolation is hard but pt. does not want metal - use what

A

zirconia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

margin design affecting

A

structural durability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

finish lines we will use

A
  1. chamfer

2. heavy deep chamfer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

chamfer for?

A

for tooth prep in which gingival aspect meets the external axial surface at an obtuse angle
- uses a round end diamond

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

chamfer for?

A

for tooth prep in which gingival aspect meets the external axial surface at an obtuse angle

  • uses a round end diamond
  • mainly used for PFM’s and zirconia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

chamfer for?

A

for tooth prep in which gingival aspect meets the external axial surface at an obtuse angle

  • uses a round end diamond
  • mainly used for PFM’s and zirconia
42
Q

heavy/ deep chamfer

A

has a 90 degree cavo-surface angle, with a large radius

radial shoulder: same with a lesser radius

rounded tapered diamond

used with ceramics

43
Q

5 principles of tooth prep

A
  1. preservation of tooth structure
  2. preservation of the periodontium
  3. retention and resistance
  4. structural durability
  5. marginal integrity
44
Q

a flat occlusal surface implication

A

may OVER SHORTEN the preparation

45
Q

convergence in terms of preservation

A

prep teeth with the MINIMUM practical convergence angle between axial walls

46
Q

bio width usually

A

2-3 mm

need 2

47
Q

margin has to be?

A

on healthy tooth structure

so caries abrasion or erosion are reasons to go sub-g

48
Q

according to richter?

A

looked at margin location and supra- vs sub gingival

no difference between

  • health of gingiva
  • change in sulcus depth
  • gingival contour
  • plaque accumulation
49
Q

geometry of tooth prep affecting?

A

retention form

  • taper
  • freedom of displacement
  • surface area
  • stress concentration
50
Q

path of insertion dimenstion

A

facio-lingual

mesio-distal

51
Q

mesio-distal path of insertion

A

must be parallel to contact areas of adjacent eeth

so if path is inclined mesially or distally - restoration will be held up at the proximal contacts and be locked out

52
Q

facio-lingaul path of insertion effects?

A

estehtics of PFM crowns or veneers

53
Q

total occlusal convergence aka

A

TOC – the angle of convergence between 2 opposing prepared axial surface

minimum 2-6

average is 14.3 to 22.1

54
Q

TOC with specific teth?

A

posterior teeth > anterior teeth

mandibular teeth > maxillary

55
Q

teeth with greatesst TOC?

A

mandibular molars

56
Q

surfaces with greater TOC?

A

facio-lingual > mesiodistal

because cheek and tongue

57
Q

FPD’s and crowns in terms of TOC?

A

FPD’s&raquo_space; crowns

b/c of path of insertion

58
Q

maximum retetnion schieved by?

A

of only one path exists

a long parallel axis walla and grooves has high retentive values

59
Q

short occluso-gingival height results in

A

more displacement

60
Q

SA and retention

A

more SA more retention

61
Q

more tapered prep how does it affect retention?

A

decreases

62
Q

wide prep with retention?

A

increases

63
Q

major factors affecting resistance

A

magnitude and direction of forces : mastication and parafunctional habits, interference’s, andterior guidance

leverage

length and width

taper

type of prep

luting agent

64
Q

leverage is

A

occurs when the line of action of a force passes OUTSIDE the supporting tooth structure

65
Q

forces outside the margin are caused by

A

wide occlusal table

crowns on tippeed teeth

cantilevers

66
Q

small prep with large restoration?

A

poor resistance as compared to small prep and smallrestoration

67
Q

OC dimension for premolars and anterior?

A

3mm is MINIMUM

- need this amount along with the recommended TOC (taper) range of 10-20 degrees

68
Q

OC dimension for molars?

A

4mm is MINIMUM
- need this amount along with the recommended TOC (taper) range of 10-20 degrees

  • usually have a greater convergence than anterior teeth and greater diameter than other teeth
69
Q

prep width with resistance

A

wider - less resistance

*example when factor is opposite for retention and resitence form

70
Q

use of axial grooves / boxes?

A

routinely when MANDIBULAR MOLARS are prepared for FIXED PARTIAL DENTURES and they should be located on the PROXIMAL SURFACES

71
Q

Facioproximal and linguoproximal corners?

A

prepared so that they are preserved sustaining variation in the curcumferential morphology that enhances resistance form

72
Q

prep is narrow, how is resitstnce?

A

good – increases

73
Q

structural durability - general

A

the ability of a restoration to withstand destruction due to external forces

74
Q

factors affecting the structural durability

A
  1. adequate tooth reduction
    - occlusal reduction
    - axial reduction
  2. alloy selection
  3. metal-ceramic frameowrk
  4. margin design
75
Q

occlusal / axial reduction for gold crown

A

occlusal - 1mm,

axial 0.5-1mm

76
Q

occlusal / axial reduction for PFM

A

occlusal 1.5

axial 1.2 - 1.5

77
Q

occlusal / axial reduction for all ceramic

A

occlusal - 2mm

axial 1-1.5

78
Q

point and internal angles?

A

ROUNDED
- avoid the deep grooves in centerl of occlusal surfaces to prevent stress concentration and to distribute the forces over a larger surface area

79
Q

tend to under-reduce where?

A

center of crown

80
Q

indications for PFM

A
  1. high strength requirements
  2. limited interocclusal clearance
  3. metal occlusal surface
  4. discolored tooth structure
  5. long span RPD
  6. abutment to RPD’s (survey crowns)
81
Q

if cant control the saliva want to be able to ___ with the final crown

A

cement

- like use of a PFM with cement - dont have to rely on bonding

82
Q

advanatges of PFM

A
  1. long history of success
  2. highly versatile
  3. less demanding tooth preparation
  4. more conservative reduction
  5. ability to mask discolored tooth
  6. use of conventional cements (not worried about saliva being a problem as much)
83
Q

indications for all ceramic crowns

A
  1. high strenght materials
  2. high esthetic expectation
  3. relatively opaque teeth
84
Q

advantages of all ceramic

A
  1. no cast metal substructure
  2. excellent esthetics
  3. durable resotration
85
Q

advantages to yttria stabalized zirconia

A
  1. fracture toughness
  2. esthetics / depends – more opaque
  3. no metal substructure
86
Q

disadvantages of zirconia

A
  1. cannot bond the restoration
  2. esthetics , cannot match translucent
  3. fusion temperature
87
Q

bond zirconia?

A

NO – cementation only

88
Q

material if issue of reduction

A

use PFM or zirconia

can get away with less reduction with both of these

89
Q

if esthetic is most important use?

A

all ceramic

even more so than zirconia

90
Q

if isolation is impossile and dont want metal?

A

zirconia

all ceramic you have to bond and will be difficult if there is a lot of saliva

91
Q

margin use what?

A

tapered round-end diamond instrument using 1/2 of its tip diameter

92
Q

two margins we use

A

chamfer and deep chamfer (all ceramic)

PFM and zirconia

93
Q

shoulder?

A

meets at 90 degrees

  • uses a flat ended
  • ceramics
94
Q

shoulder with bevel?

A

used for PFM’s where a shoulder was prepared but because of caries or presence of restoration , a bevel is added

95
Q

a bevel?

A

a slanting edge, the process of slanting the finish line and curve of a tooth preparation

  • allows the cast metal margin to be bent or burnished against the prepared tooth structure
  • minimize the marginal discrepency
  • removes unsupoorted enamel
96
Q

TOC

A

total occlusal convergance - angle of convergance between 2 opposing prepared axial surfaces

should meet the recommended 2 to 6 degree minimal angle

axial walls of the prep must taper slightly to permit the restoration to seat

97
Q

why does facial - lingual have more taper?

A

cheek and tongue - dont want to hit them

98
Q

forces outside the margin are caused by

A

wide occlual table

crowns on tipped teeth

cantilevers

99
Q

shortening prep results in

A

less resistance – the lfiting force required is smaller

100
Q

if mechanical properties are compromised bond or cemetn

A

bond

Fixed Prosth 3rd year (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions