Design

Question 1

kennedy class i

Answer 1

bilateral free end saddle

Question 2

kennedy class ii

Answer 2

unilateral free end saddle

Question 3

kennedy class iii

Answer 3

bounded saddle

Question 4

kennedy class iv

Answer 4

anterior bounded saddle that crosses midline

Question 5

how do you prioritise what saddle to name using the kennedy classification

Answer 5

always use lowest classification possible then add a modification number for each additional saddle

Question 6

craddock class 1

Answer 6

tooth borne - saddles supported on both sides by abutments and saddles are not more than 3 teeth wide

Question 7

craddock class 2

Answer 7

mucosa borne - vertical biting forces resisted entirely by soft tissues

Question 8

craddock class 3

Answer 8

both tooth and mucosa borne

Question 9

if considering an abutment for a clasp what else should the abutment have and why

Answer 9

a rest, to prevent clasp sinking to gingival margin

Question 10

gingivally approaching clasp

Answer 10

approach undercut via gingival margin and do not cross maximum bulbosity of the tooth
useful on narrow teeth i.e anteriors and pre molars

Question 11

occlusally approaching clasp

Answer 11

approach undercut from occlusal side of survey line therefore crosses maximum bulbosity of the tooth
commonly seen on molars

Question 12

ring clasp

Answer 12

also known as self reciprocating clasp

type of occlusally approaching clasp

Question 13

what is the recommended pattern of retention

Answer 13

triangular

however some situations only allow for two

Question 14

how are rests named

Answer 14

according to where they sit/ contact the tooth e.g occlusal, cingulum , incisal

Question 15

do rests work best on metal or acrylic bases

Answer 15

metal as they are an integral part of the framework whereas on acrylic bases they need to be added and have potential to weaken base

Question 16

where are the default positions for bounded saddle rests

Answer 16

immediately adjacent to the saddle

Question 17

where is the default position for a free end saddle rest

Answer 17

opposite side of abutment tooth to saddle

Question 18

why should rests be of sufficient enough size that they extend near the midline of the tooth

Answer 18

to ensure they can apply/ transfer load down long axis of tooth

Question 19

name 3 risks associated with preparing rest seats

Answer 19

dentine exposure
destruction of tooth surface
loss of occlusal stop when denture not worn

Question 20

Name 5 benefits of occlusal rests

Answer 20

prevent movement of rpd towards mucosa 
prevent overerruption of unopposed teeth 
distribute occlusal load 
possibility of indirect retention 
helps determine axis of rotation

Question 21

indirect retention

Answer 21

resistance to rotational displacement

Question 22

retention

Answer 22

resistance to vertical displacement

Question 23

reciprocation

Answer 23

prevents clasp arm moving clasp tooth

Question 24

bracing

Answer 24

resistance to lateral movements

Question 25

on what type of saddles is indirect retention more of an issue

Answer 25

free end saddles

indirect retention not really an issue on bounded saddles

Question 26

what are examples of indirect retainers

Answer 26

rests, connectors, saddles

Question 27

why should there be good clearance between the gingival margin and a reciprocal arm

Answer 27

to ensure maintenance of good oral hygiene

Question 28

on what type of rpd is bracing not a common problem

Answer 28

rpds that have components on both sides of the mouth