Retention and Stability

Question 1

retention

Answer 1

resistance to vertical displacement

Question 2

stability

Answer 2

resistance to horizontal displacement (function)

Question 3

adhesion

Answer 3

physical attraction of unlike molecules for each other e.g saliva and denture base, saliva and mucous membrane

Question 4

cohesion

Answer 4

physical attraction between similar molecules

Question 5

what is a good baseline depth for a post dam

Answer 5

0.5mm

Question 6

why are denture adhesives not recommended for all patients

Answer 6

denture adhesives move denture base slightly away from tissues compromising the adhesion/cohesion gained from saliva

Question 7

if using a denture adhesive how much and where should it be placed

Answer 7

2 small blobs bilaterally at back and one at front

Question 8

Name 3 different materials available for denture teeth

Answer 8

acrylic based
porcelain based (require retentive tag to adhere to base)
composite resin based

Question 9

illuminant metameric failure

Answer 9

light source alters appearance meaning shades dont match under two varying lights

Question 10

observer metameric failure

Answer 10

operator error results in wrong colour match
e.g colour blindness , genuine error
ask nurse for second opinion

Question 11

Leon Williams Classification

Answer 11

states that tooth shape should match inverted face shape
no modern evidence supporting this theory

Question 12

Frush and Fischer dentogenic concept

Answer 12

states that males should have square angular teeth and females curved and rounded
no modern evidence supporting this

Question 13

in relation to the ridge , where should upper teeth be places

Answer 13

slightly buccal

Question 14

Name 5 things to check at the denture try in stage

Answer 14

retention and stability
base extensions
Lip support
Incisal level
M idline
B uccal corridors
Occlusal planes
vertical dimension and FWS
position of teeth in comparison to soft tissues
speech
aesthetics
even occlusal contacts

Question 15

how can you test for underextension during try in

Answer 15

hold tissues away, if underextended denture will drop

Question 16

how can you test for an overextended denture during try in

Answer 16

over extended denture will drop when surrounding tissues are manipulated

Question 17

how can speech be tested during try in of a denture

Answer 17

testing fricatives (f, v, s)
ask patient to say missisippi, the days of the week or count from 60 to 70

Question 18

should upper or lower denture be inserted / removed first

Answer 18

lower should be recommended to be removed and inserted first

Question 19

what makes up the pellicle layer

Answer 19

salivary proteins and bacterial products

Question 20

what makes up denture debris

Answer 20

mainly plaque biofilm, food and calculus

Question 21

what microorganisms might be found on a denture

Answer 21

bacteria - staphylococcus aureus, E.coli
fungi - candida

Question 22

why does the environment under a denture favour candida

Answer 22

it is more acidic than rest of mouth