Denture Pros Exam

Question 1

what is kennedy class 1?

Answer 1

bilateral free end saddle

Question 2

what is kennedy class 2?

Answer 2

unilateral free end saddle

Question 3

what is kennedy class 3?

Answer 3

bound saddle not crossing midline

Question 4

what is kennedy class 4?

Answer 4

bound saddle crossing midline

Question 5

why is reciprocation required?

Answer 5

to prevent tooth movement

Question 6

what should a clasp be when seated?

Answer 6

passive

Question 7

what dimensions are required for a mid palatal bar?

Answer 7

7-12mm

Question 8

what materials should be used for a gingivally approaching clasp?

Answer 8

cobalt chrome or stainless steel

Question 9

give a benefit of an I bar

Answer 9

puts less stress on the tooth

Question 10

name other types of clasp deisgn

Answer 10

ring clasp
occlusally approaching clasp
3 arm clasp

Question 11

what crown height is required for a dental bar?

Answer 11

9mm

Question 12

what is the bar width and gingival/incisal clearance for a dental bar?

Answer 12

5mm bar width
2mm clearance from gingival margin
2mm clearance from incisal tip

Question 13

give a benefit of a dental bar design over a plate design?

Answer 13

more hygenic than plate design

Question 14

when should a dental bar not be used?

Answer 14

when there’s spacing between teeth

Question 15

what is a distinctive feature of the lingual bar? what do these do?

Answer 15

cummer arms - they provide indirect retention to prevent a posterior uplift

Question 16

what sulcus depth is required for a lingual bar? how much clearance from the gingival margin should the lingual bar have?

Answer 16

7mm sulcus depth required
lingual bar should be 3.5mm away from gingival margin

Question 17

when is the use of a lingual bar advantageous?

Answer 17

when the pt has anterior spacing

Question 18

what undercut depth would Co/Cr clasps be used for?

Answer 18

0.25mm

Question 19

what undercut depth would SS clasps be used for?

Answer 19

0.5mm

Question 20

what undercut depth would gold clasps be used for?

Answer 20

0.75mm

Question 21

what clasp material is the least and most flexible?

Answer 21

Co/Cr is least flexible
Gold is most flexible

Question 22

how is undercut gauge used and what does it determine?

Answer 22

undercut gauge drawn up against the tooth
where the gauge touches the tooth is the point where the clasp should terminate (where terminal 1/3rd of clasp engages)

Question 23

how does finishing point of SS clasp compare to finishing point of Co/Cr?

Answer 23

SS clasp finishes further down tooth further away from the survey line - as more flexible and engages a deeper undecrut

Question 24

name 3 types of articulator

Answer 24

1. plane line
2. average value
3. semi adjustable w/ facebow - has measurements written on it

Question 25

what incisal angle and condyle width is average value set to?

Answer 25

incisal angle of 10 degrees average condyle width = 25mm

Question 26

what does a facebow record?

Answer 26

to record the relationship between the maxilla and TMJ

Question 27

list 4 advantages of injection moulding over dough packing

Answer 27

1. no flash in injection moulding which minimises the risk of an open bite when fitting the dentures 2. no trial pack 3. less handling of material required 4. less pressure when injecting material

Question 28

list 5 disadvantages of injection moulding over dough packing

Answer 28

1. need to add sprue 2. extra training required 3. expensive 4. difficult to de-flask - as you have the sprue to contend with as well 5. technique sensitive

Question 29

how does flash thickness affect denture thickness?

Answer 29

inc flash thickness increases denture thickness

Question 30

how does an open bite present on the articulator?

Answer 30

pin will not touch the table

Question 31

what method increases the risk of an open bite/pin not touching the table? why?

Answer 31

dough packing - due to inc flash thickness

Question 32

what 2 errors can cause contraction porosity?

Answer 32

not enough pressure on the mould not enough material to fill the mould

Question 33

what 2 things can cause gaseous porosity?

Answer 33

wrong curing cycle heating too rapidly - causing the MMA monomer to boil

Question 34

where in denture does gaseous porosity occur?

Answer 34

in the thickest part of the denture

Question 35

what can occur if alginate impression is left in the disinfectant solution for too long?

Answer 35

Imbibition - absorption of one substance by another

Question 36

what can occur when the alginate impression is not kept in a sealed bag with damp napkins?

Answer 36

Syneresis - alginate expulses liquid causing shrinking of impression

Question 37

where is the hamular notch found?

Answer 37

behind the tuberosities of the maxilla

Question 38

where is the raphe found?

Answer 38

running down midline of the palate

Question 39

what does the willis gauge record?

Answer 39

the OVD

Question 40

what does the Fox's Guide Plane measure?

Answer 40

the level of the occlusal plane

Question 41

when are flat cusped teeth used?

Answer 41

when the patient's bite is non reproduceable

Question 42

what material is used for soft linings?

Answer 42

molloplast

Question 43

is it better to have a thinner or thicker soft lining? why?

Answer 43

better to have thinner soft lining a thicker soft lining would mean less acrylic on the denture which would weaken the denture

Question 44

when is a denture rebase required? (2)

Answer 44

when the denture is loose fitting when teeth are worn or loose

Question 45

what should be done to the denture prior to taking a wash impression?

Answer 45

remove undercuts

Question 46

when is a closed bite technique used?

Answer 46

to avoid occlusal errors such as an open bite

Question 47

how is closed bite technique used?

Answer 47

wash placed over fitting surface of denture and placed into mouth - pt bits down

Question 48

what indicates that the mould is full during injection moulding?

Answer 48

resin exits the mould as the clamp handle is turned and piston pushes resin into the mould

Question 49

what type of clasps is undercut gauge used to select material for?

Answer 49

occlusally approaching

Question 50

what term is used to describe the change in length of a specimen?

Answer 50

ductility - a materials ability to be stretched/pulled

Question 51

what term is used to describe an elongated specimen?

Answer 51

tensile specimen

Question 52

what force is required to flatten a specimen?

Answer 52

compressive force

Question 53

what term is used to describe the hardness of a material?

Answer 53

modulus = stiffness of material

Question 54

what force is applied to a mid beam to fracture it?

Answer 54

3 point flexural strength

Question 55

label the medial pterygoid

Answer 55

runs vertically

Question 56

label the buccinator

Answer 56

underneath masseter - runs from mouth posterior to medial pterygoid

Question 57

label the condyle

Answer 57

posterior to coronoid

Question 58

label the obicularis oris

Answer 58

around mouth

Question 59

label the nasalis

Answer 59

over nose

Question 60

label the masseter

Answer 60

superficial to buccinator exits zygoma and inserts into angle of mandible

Question 61

label the zygomaticus major

Answer 61

runs from zygoma down to orbicularis oris

Question 62

label the temporalis

Answer 62

flat on lateral of skull - inserts down into zygoma

Question 63

label the coronoid process

Answer 63

anterior to condyle

Question 64

label the mental nerve

Answer 64

runs down onto chin

Question 65

what is dental gypsum used for?

Answer 65

impression plaster, dental plaster and dental stone - study casts

Question 66

list 3 non elastic impression materials

Answer 66

impression plaster impression compound zinc oxide eugenol cannot record undercuts so only use in edentulous areas

Question 67

what is alginate used and not used for?

Answer 67

used for - study models, removable partial dentures, for temporary crown/bridges, creation of special trays, mouth guards, bleaching trays not used for crown and bridge definitive restorations as bad detail

Question 68

name 4 non-aqueous elastomeric impression materials (hydrophobic)

Answer 68

polysulfides - good for big undercuts (inlays, crowns, bridges) polyethers - avoid in big undercuts (crowns, bridges, partial dentures and implants) condensation silicones addition silicones

Question 69

what is zinc oxide eugenol impression material used for?

Answer 69

secondary impressions for complete dentures

Question 70

what is alginate used for?

Answer 70

primary impressions for dentures opposing arch impressions for crowns/bridge models

Question 71

what are polysulphides used for?

Answer 71

complete dentures - long working time required

Question 72

what are polyether used for?

Answer 72

final impressions for crowns, bridges, partial dentures and implants avoid in deep undercuts and bridges

Question 73

what is addition and condensation silicone used for?

Answer 73

crowns, bridges, partial dentures and implants

Question 74

name 2 aqueous elastomeric impression materials (hydrophillic)

Answer 74

alginate and agar