PARTIAL DENT - Introduction

Question 1

define support for dentures

Answer 1

the resistance to vertical force
- directed towards the mucosa

Question 2

2 basic structures which give support for dentures

Answer 2

teeth or mucosa

Question 3

give 4 examples of ways you may gain tooth support

Answer 3

occlusal rests
cingulum rests
incisal rests
onlays

Question 4

give 3 examples of mucosal borne denture

Answer 4

spoon denture
every denture
transitional denture

Question 5

define saddle

Answer 5

an edentulous region of the alveolar ridge

Question 6

define bounded saddle

Answer 6

a saddle with a tooth at each end

Question 7

define free ended saddle

Answer 7

an edentulous area with teeth at one end

Question 8

define retention

Answer 8

the resistance to vertical forces directed away from the mucosa

Question 9

how can retention be gained?

Answer 9

clasps

Question 10

how do clasps gain retention

Answer 10

they engage undercut

Question 11

where can you find the undercut?

Answer 11

it is the area below the survey line
(line of maximum bulbosity)

Question 12

clasps can be approached in 2 directions..

Answer 12

gingival approach
occlusal approach

Question 13

define bracing

Answer 13

having resistance to a horizontal force

Question 14

define reciprocation

Answer 14

resistance to the specific horizontal forces generated by a retentive clasp

Question 15

which clasps MUST always be reciprocated?

Answer 15

retentive clasps

Question 16

what is indirect retention? how is it achieved?

Answer 16

resistance to rotational displacement

place a rest on a tooth anterior to the clasp

Question 17

define the sulcus

Answer 17

the space that has been produced between the tongue/lips/cheek and alveolar ridge

Question 18

what is the functional depth of sulcus?

Answer 18

the minimum depth of the sulcus when muscles are contracting

Question 19

define a flange

Answer 19

the part of the denture which extends into the sulcus

• should extend to the functional depth of the sulcus

Question 20

when would a denture be over-extended? what happens as a result

Answer 20

if the flange extends beyond the functional depth of sulcus

= unstable denture function

Question 21

when is a denture under-extended? what happens as a result?

Answer 21

when the flange doesn’t extend to the functional depth of the sulcus

Question 22

define occlusion

Answer 22

the precise way in which teeth in upper arch meet lower arch teeth

Question 23

what is denture occlusal instability?

Answer 23

when teeth meet incorrectly and make the denture unstable, usually from premature contact

Question 24

requirements of occlusal rests.

Answer 24

• up to 1/3 across occlusal surface
• down the long axis of the tooth
• clear from occlusion

Question 25

what is the horizontal depth of undercut for Cobalt/Chrome?

Answer 25

0.25mm

Question 26

what is the length of a standard clasp and why?

Answer 26

15mm

to be flexible enough to go in and out of undercut without distorting beyond elastic limit

Question 27

what are guide planes?

Answer 27

flat surfaces
cut into enamel of adjacent tooth
parallel to the path of insertion

Question 28

what is a RPI clasping system

Answer 28

Rest - medial rest
Plane - distal guide plane
I-bar - I-bar clasp

Question 29

where are RSI clasping systems used?

Answer 29

on lower free end saddles

Question 30

what is a connector?

Answer 30

rigid component holding other components together

Question 31

what is a major connector?

Answer 31

connector connecting the left and right side

Question 32

what is a minor connector

Answer 32

branching from the major connector to the various components - clasps, rests

Question 33

describe the Kennedy Classification

Answer 33

class 1
- bi-lateral free end saddle

class 2
- unilateral free end saddle

class 3
- bounded saddle denture

class 4
- saddle anterior to abutments