2. Introduction to Partial Dentures

Question 1

Reasons patients lose teeth (6)

Answer 1

Caries
Periodontal disease
Endodontic infection
Trauma
Cancer
Hypodontia

Question 2

Consequences of missing teeth (4)

Answer 2

Anatomical (extra-oral, intra-oral)
Aesthetics (loss of hard and soft tissues which support the face)
Functional (mastication, speech)
Psychological

Question 3

Features of SDA (4)

Answer 3

20 teeth - minimum number to function correctly
Most posterior teeth are missing
Satisfactory oral function without the use of an RPD
Priority given to maintaining an anterior and premolar dentition in one/both jaws

Question 4

When does the SDA occur

Answer 4

When there is sufficient capacity in subjects when there is sufficient adaptive capacity in subjects when 3-5 occlusal units (OU) are left

Question 5

Indications for retaining SDA (5)

Answer 5

Missing posterior teeth with 3-5ou remaining
Sufficient occlusal contacts to provide a large enough occlusal table
Favourable prognosis for remaining anterior and premolar teeth
Patient not motivated to pursue complex restorative plan
There are limited financial resources on dental care

Question 6

Contraindications for retaining SDA (5)

Answer 6

If there is a poor prognosis for remaining dentition
Untreated or advanced periodontal disease
Pre-existing TMJ dysfunction
Signs of pathological tooth wear
Significant malocclusion (severe class II or III)

Question 7

Methods of extension of SDA (3)

Answer 7

Resin-bonded bridges
RPDs
Implant-supported prostheses

Question 8

Reasons for resin-bonded bridges extension of SDA (4)

Answer 8

Max of one unit on each side of arch
Light contact on pontics in ICP
Minimal contact in excursion
Heavy contacts may lead to failure

Question 9

Reasons for RPD extension of SDA (2)

Answer 9

Bilateral free-end saddle

RPI design

Question 10

Reasons for implant-supported prostheses extension of SDA (2)

Answer 10

Single tooth

Cantilever/fixed bridge

Question 11

Types of RPD support (3)

Answer 11

Tooth borne
Mucosa borne
Tooth and mucosa borne
(Made from CoCr or PMMA)

Question 12

Indications for RPD (6)

Answer 12

Multiple missing teeth
No suitable bridge abutments
Implants contraindicated
Immediate after extraction
Provisional during implant treatment
Transitional to complete denture

Question 13

Contraindications for RPD (5)

Answer 13

Untreated dental disease
Chronic poor oral hygiene
Patient acceptance
SDA that patient can function with
Mobile teeth (unless transitional denture)

Question 14

Advantages of RPDs (4)

Answer 14

Simple
Restore function
Restore appearance
Cost effective

Question 15

Disadvantages of RPDs (4)

Answer 15

Plaque retention
Aesthetics (clasps and flanges)
Denture stomatitis
Compromise abutment teeth

Question 16

Types of extra-oral exam (6)

Answer 16

Lower facial height
Naso-labial angle
Limited opening
Any abnormalities
Smile line
Aesthetics of existing dentures

Question 17

Types of intra-oral exam (10)

Answer 17

Periodontal status (BPE)
Endodontic status
Caries
Tooth wear (active)
Indirect restorations (crowns, bridges; dismantle)
Potential abutments
Freeway space
Edentulous spaces (number, position, length, ridge form, displaceable tissue)
Health of denture-bearing area Occlusion (inter maxillary space, occlusal contacts)

Question 18

Types of Kennedy classifications (4)

Answer 18

Kennedy class I
Kennedy class II
Kennedy class III
Kennedy class IV

Question 19

Definition of Kennedy class I

Answer 19

Bilateral free-end saddle
Bilateral edentulous areas located posterior to the remaining natural teeth. Denture saddles that restore such edentulous areas are described as ‘distal extension saddles’

Question 20

Definition of Kennedy class II

Answer 20

Unilateral free-end saddle

A unilateral edentulous area located posterior to the remaining natural teeth

Question 21

Definition of Kennedy class III

Answer 21

Posterior unilateral bounded saddle
A unilateral edentulous area with natural teeth remaining both anterior and posterior to it. Denture saddles that restore this type of edentulous area are said to be ‘bounded saddles’

Question 22

Definition of Kennedy class IV

Answer 22

Anterior bounded saddle that crosses the midline

A single edentulous area located anterior to the remaining natural teeth

Question 23

Types of Craddock classifications (3)

Answer 23

Craddock class I
Craddock class II
Craddock class III

Question 24

Definition of Craddock class I

Answer 24

Tooth borne support

Saddles supported on both sides by substantial abutments

Question 25

Definition of Craddock class II

Answer 25

Mucosa borne support

Vertical biting forces resisted entirely by soft tissues

Question 26

Definition of Craddock class III

Answer 26

Tooth and mucosa borne support

Tooth supported at only one end of the saddle

Question 27

Components of denture examinations (10)

Answer 27

Aesthetics
Support
Retention
Stability
Extension
Occlusion
Material
Design
Condition of teeth (healthy tooth required for abutments)
Condition of base

Question 28

Definition of support

Answer 28

The resistance to vertical movement of the denture towards the tissue

Question 29

Definition of retention

Answer 29

The resistance to displacement of the denture away from the tissue

Question 30

Definition of stability

Answer 30

The resistance to horizontal (lateral) movement of the denture