RPD retention

Question 1

retention components

Answer 1

physical forces (adhesion, cohesion)
muscular
mechanical

Question 2

mechanical retention

Answer 2

engags undercut

POI different to POD

Question 3

how to create a POD different to POI

Answer 3

block out undercuts relative to path of dispalcement

- creates resistance to displacment and therefore retention

Question 4

creating a path of insertion

Answer 4

• Survey
• change angle so it fits in the undercut
• this creates the path of insertion
• have to block out the undercut on the other tooth using that angle
• undercut is engaged in the mesial aspect as seen below

Question 5

types of clasps

Answer 5

gingivally approaching
occlusally approaching
claps tip provides the retention by engaging the undercut

Question 6

occlusal clasps

Answer 6

occlusal rests on the surface

engages undercut above survey line

Question 7

gingival clasps

Answer 7

start in the saddle area

engages undercut from gigniva

Question 8

undercuts and clasps

Answer 8

clasp arm provides the flexibilty of the clasp min 14mm
clasp arm needs to engage undercut
claps arm follows survey lines

Question 9

rules of clasps

Answer 9

1) clasp each abutment tooth
2) occlusally approaching on posterior
- more hygienic
3) gingingivally approaching
- aesthetic