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Flashcards in Quiz 2 Review Deck (95):
1

what are some of the indications for an FPD?

-medical contraindication to implants

-grossly inadequate alveolar bone for implant placement

-treatment following implant failure

-patient time constraints and/or circumstances that preclude implant placement

-patient that does not want an implant

2

of partial coverage and full coverage bridges, which is more retentive?

full coverage

3

what is an abutment tooth?

the tooth that supports the FPD

4

what is the retainer part of an FPD?

the crown

5

what is a pontic?

the missing tooth

6

what is the connector on an FPD?

the joint between the teeth

7

what is a splinted crown useful for?

teeth that are going to be abutments for an RPD, perio/mobility, or increased retention

8

what are the disadvantages of splinted crowns?

-flossing is compromised

-if one fails, they both fail

-retrievability is complicated

9

label this

Q image thumb

A image thumb
10

T or F:

all of the same factors that influence resistance and retention for single units apply to fixed bridges

true

11

retainers with increased ___ height are more retentive than retainers with decreased ___ height

axial wall, axial wall

12

does increased abutment taper increase or decrease the resistance and retention of the retainers?

decreases

13

why is abutment taper of increased out of necessity? what can this increased axial wall taper create?

  • to align abutments and allow a path of insertion
  • it can create extra stresses on pulpal tissues

14

part of the pre-operative assessment for fixed bridges should always include the alignment of the proposed ___

abutment teeth

15

what are 5 fixed bridge designs?

  • pier to pier (pier refers to the abutment)
  • pier to pier to pier
  • cantilever
  • keyway feature
  • combinations

16

why should you avoid the pier to pier to pier fixed bridge design?

the terminal abutments will often loosen and the middle abutment becomes a fulcrum

17

T or F:

a double abutment refers to two abutment teeth right next to each other, which is a better option than a pier to pier to pier design

true

18

how many pontics can be used in a cantilever bridge?

  • one pontic only
  • this is not an absolute, but will keep you out of trouble

19

with cantilever bridges, where should the pontic be? what is the exception?

  • the pontic should be mesial to the retainer
  • except maxillary central carrying a maxillary lateral
  • this is not an absolute, but will keep you out of trouble

20

which two single abutments cannot be used with cantilever bridges?

  • mandibular incisor or maxillary lateral incisor
  • this is not an absolute, but will keep you out of trouble

21

___ rests should be used when possible with cantilever bridges

  • cingulum/marginal ridge rests
  • this is not an absolute, but will keep you out of trouble

22

based on clinical results of a 2-unit cantilevered resin-bonded fixed partial denture, they are found to be a durable prosthesis over the long term with high patient satisfaction. what is the consideration with the posterior prosthesis?

it has a higher failure rate, and improved design features should be considered (the janis bridge)

23

list 11 factors to consider with bridges

  • parafunctional habits
  • periodontal health
  • plaque control/caries susceptibility
  • occlusion
  • root angulation
  • root form
  • root surface area
  • retrievability
  • crown/root ratio
  • length of span
  • endodontic health

24

what are 6 occlusion considerations for bridges?

  • is the TMJ complex healthy?
  • are the condyles seated?
  • are occlusal forces controlled?
  • does the bridge involve the patient's anterior guidance?
  • is an occlusal adjustment indicated?
  • should splint therapy be considered?

25

what are parafunctional considerations for bridges?

  • accelerated occlusal wear?
  • tooth mobility?
  • temporomandibular pain?
  • tooth fracture?
  • are the same factors that contributed to the tooth loss unresolved?

26

whata re root angulation considerations for bridges?

  • are the roots in line with occlusal forces?
  • if not, how much off angle is acceptable?
  • is orthodontic uprighting necessary?
  • us orthodontic uprighting possible?

27

if root angulation is off, what is it sometimes necessary to do in preparation for a bridge?

  • recontour the proximal contacts of adjacent teeth
  • prepare abutment teeth off-axis

28

if root angulation is off, pre-operative ___ therapy can significantly enhance long-term prognosis of prosthodontic therapy

orthodontic

29

what are root form considerations for bridges?

  • conical and short vs irregular and long?
  • are there thin areas, especially concavities, that are especially prone to fracture?

30

what is ante's law? what year was it developed? what is the exception?

  • the total periodontal membrane area of the abutment teeth must equal or exceed that of the teeth to be replaced
    • in other words, the total root surface area of the teeth to be replaced should not be greater than the total root surface area of the abutment teeth
  • 1926
  • really long canines are the exception

31

ante's law is useful for determining ___ of fixed dental prostheses

prognosis

32

with respect to percentage of root surface area per quadrant, the maxillary central and lateral incisors together make up about ___% of the total for the maxilla, and the mandibular central and lateral incisors together make up about ___% of the total for the mandible. 

  • maxilla: 19% (central = 10, lateral = 9)
  • mandible: 17% (central = 8, lateral = 9)

33

which tooth overall has the greatest PERCENT root surface area?

mandibular first molar

34

which tooth overall has the greatest root surface area?

maxillary first molar

35

with respect to crown/root ratio, the ___ of roots accelerates the negative impact of crestal bone loss

conical shape

36

the deflection of a fixed dental prosthesis is proportional to the ___

  • cube of the length of its span
  • so, D = F x S3
    • D = deflection
    • F = force
    • S = span

37

what is the deflection of a bridge with 1 pontic, 2 pontics, and 3 pontics?

  • D = F x S3
  • assume F = 1
  • 1 pontic: D = 1 x 13 = 1
  • 2 pontics: D = 1 x 23 = 8
  • 3 pontics: D = 1 x 33 = 27

38

T or F:
a double abutment at the terminal end of a FPD is considered a pier abutment

  • false, it is not considered a pier abutment
  • for it to be considered a pier abutment, there must be a pontic separating the two retainers

39

a double abutment is an acceptable method of increasing ___ support for a FPD

periodontal

40

every tooth that is included in a fixed bridge increases the vulnerability of ___

  • every other tooth that is part of the same bridge
  • what affects one, now affects them all

41

T or F:

when designing FPDs, retrievability is not an important consideration

false, it's definitely important

42

a ___ is an artifical tooth replacing a missing natural tooth that is designed to restore function and appearance

pontic

43

what are 5 pontic types?

  • sanitary/hygienic
  • saddle/ridge-lap
  • conical/bullet
  • modified ridge-lap
  • ovate/socketed

44

what type of pontic is this?

Q image thumb

sanitary/hygienic

45

what type of pontic is this?

Q image thumb

saddle ridge-lap

46

what type of pontic is this?

Q image thumb

conical

47

what type of pontic is this?

Q image thumb

modified ridge-lap

48

what type of pontic is this?

Q image thumb

ovate

49

what is the minimum clearance for a sanitary/hygienic pontic?

2mm

50

in the modified ridge lap, the area that contacts tissues resembles what letter?

T

A image thumb
51

put the following pontic designs in descending order of strength

Q image thumb

strength is based on cross-sectional diameter of the metal substructure

A image thumb
52

which of the following is the correct design?

Q image thumb

A image thumb
53

how can pontics be adjusted to create the illusion of being smaller or larger?

  • line angles can be adjusted
  • this can be applied to any prosthesis, retainer, crown, or pontic

54

positioning the ___ can help to create a width illusion

  • buccal occluso-gingival height of contour
  • this applies to any prosthesis, retainer, crown, or pontic

55

what are 4 types of connectors?

  • cast metal connector
  • soldered connector
  • ceramic connector
  • nonrigid connector (keyway or mortise and tenon)

56

put the following connectors in order of decreasing strength: soldered metal, all ceramic (zirconia, lithium disilicate, cast metal)

cast metal > soldered metal > all ceramic

57

T or F:

connectors with larger dimensions have less strength than smaller connectors

false

58

how do you calculate the area of a circular connector?

πr2

59

how do you calculate the area of a elliptical connector?

  • abπ
    • a = radius of long side
    • b = radius of short side

60

between a connector with a longer BL width versus a longer occluso-gingival width, which will best resist occlusal loading?

the one with a longer occluso-gingival width

61

what are the minimum recommended cross-sectional dimensions for 3-unit posterior connectors for cast metal, solder, and ceramic (zirconia vs lithium disilicate)?

  • cast metal = 6mm2
  • solder = 9mm2
  • zirconia = 9mm2
  • lithium disilicate = 16mm2 (this is too big for more applications)

62

where is the connector position?

Q image thumb

A image thumb
63

what are 3 nonrigid connector designs?

  • keyway
  • mortise and tenon
  • male and female

64

what are 6 most common reasons for bridge failures?

  • fractured porcelain
  • recurrent caries
  • loosened single retainer
  • fracture abutment
  • connector failure
  • excessive gap formation between pontic(s) and the edentulous ridge, especially in the anterior region

65

what are 2 important things to advise your FPD patients?

  • everything we do has a life expectancy
  • even under the best of circumstances, there will be food traps with either a bridge or an implant

66

many studies demonstrate that shortened dental arches comprising the ___ and ___ regions can meet the requirements of a functional dentition. consequently, when priorities have to be set, restorative therapy should be aimed at preserving these parts of the dental arch 

anterior and premolar

67

for chewing purposes, the minimum shortening of dental arches should include a pair of ___ in addition to intact ___

a pair of occluding molars in addition to intact premolar region

68

oral function is adequate in shortened dental arches comprising of intact ___ and ___ regions

anterior and premolar regions

69

T or F:
studies have shown that shortened dental arches often provoke signs and symptoms associated with temporomandibular disorders

  • false
  • no evidence was found that SDAs provoked signs and symptoms associated with temporomandibular disorders
  • however, complete absence of posterior support unilaterally or bilaterally appeared to increase the risk for developing signs and symptoms associated temporomandibular disorders

70

extreme SDAs, comprising 0-2 pairs of occluding premolars, had significantly more ___, ___, and ___ compared to intermediate categories of SDAs

  • interdental spacing
  • occlusal contact
  • vertical overlap
  • *occlusal wear and tooth mobility were also highest in extreme SDAs

71

satisfactory chewing ability is perceived as long as the dental arch comprises an intact ___ region and ___ occluding pairs of teeth posteriorly

  • anterior
  • 3-5

72

SDAs comprising 3-4 occluding pairs of premolars posteriorly did not significantly differ from complete dental arches with regard to ___, ___, ___, and ___

  • interdental spacing
  • occlusal tooth wear
  • vertical overbite
  • tooth mobility

73

the risk to occlusal instability seemed to occur in extreme SDAs comprising ___ occluding pairs of teeth whereas no such evidence was found for intermediate categories of SDAs

0-2

74

as long as ___ support is present bilaterally, signs and symptoms of temporomandibular disorders are unlikely to manifest themselves. increased risk was only found when ___

  • premolar
  • increased risk was only found when all posterior support was unilaterally or bilaterally absent

75

how many occluding units denotes a severely compromised SDA? what about adequate SDA? functional SDA?

  • 0-2 OU is severely compromised and likely to continue deteriorating
  • 3-4 OU is often adequate
  • 5+ OU, though not ideal, is often very functional

76

what are 6 contraindications to shortened dental arches?

  • marked dento-alveolar malrelationship - severe angle class II or III relationship
  • parafunction - intensive bruxism
  • pre-existing TMD
  • advanced pathological tooth wear
  • advanced periodontal disease - marked reduction in alveolar bone support
  • patient under age 40

77

the survival of 3-unit tooth supported fixed dental prostheses and implant supported single crowns over 15 years was not statistically different when replacing ___ teeth, but implant supported single crowns survived significantly better when replacing ___ teeth

posterior, anterior

78

T or F:

removable, fixed, fixed-removable, and implant-supported prostheses all produced significant improvement in oral health related quality of life

true

79

among patients treated with removable, fixed, fixed-removable, and implant-supported prostheses, the least amount of improvement was observed in patients with ___

removable dental prostheses

80

among patients treated with removable, fixed, fixed-removable, and implant-supported prostheses, oral health related quality of life was comparable between which two?

FPDs and implant-supported fixed prostheses

81

among patients treated with removable, fixed, fixed-removable, and implant-supported prostheses, the same treatment can have different impacts on the oral health related quality of life of partially edentulous individuals depending on their ___ and ___

age and kennedy classification

82

what are the ideal reduction measurements for an anterior bridge preparation?

  • facial depth at margin = 1.2-1.7mm
    • use two-plane facial reduction
  • lingual depth at margin = 0.5-1.0mm
  • incisal reduction = 2.0-2.5mm
    • incisal edge should be perpendicular to the long axis of the tooth
  • lingual concavity depth = 1.0-1.5mm
  • softened line and point angles

83

how much clearance do you want between opposing teeth when prepping a tooth for a bridge?

1.0-1.5mm

84

T or F:
when taking a bite registration, you only want to inject the impression material over the prepared teeth

true

85

once trimmed, the bite registration should not contact what?

  • soft tissue
  • occluding surfaces of teeth not diretly involved with the preparations

86

when curing a temporary bridge, what order should you cure it?

  • pontic area first, then move to retainer teeth
  • after removing the temporary, cure the intaglio surface

87

T or F:
triad material bonds to composite resin foundation materials

true

88

proper embrasure form of temporary bridges enhances what 3 things?

esthetics, cleansability, and gingival health

89

custom tray material should extend ___mm onto soft tissue when possible

5-10mm

90

the custom tray handle should attach at ___ degrees at the incisal edge

45-60 degrees

91

when curing the custom tray in the triad machine, it should initially cure for ___ minutes, then the tray should be removed from the model/wax, then cured again for ___ minutes per side

  • 1 minute
  • 4 minutes per side

92

what are the 4 advantages of custom trays for fixed prosthodontics?

  • comfortable for patient
  • stiff and unbendable
  • less impression material
  • consistent accuracy

93

what are the indications for a custom tray?

  • 3+ units
  • bridges
  • removable partial dentures
  • implants

94

what are the advantages of rigid stock trays?

  • less time intensive
  • variety of sizes
  • customizable

95

what are the disadvantages of rigid stock trays?

  • requires more impression material
  • requires more time chairside if not made, pre-clinically, from patient's cast