Bridgework

Question 1

What is a bridge?

Answer 1

a prosthesis which replaces a missing tooth/ teeth and is attached to one or more teeth

Question 2

Indications for bridgework

Answer 2

Function and stability
speech
psychological reasons
Systemic diseases - e.g epiletics
co-operative patients

Question 3

Contraindications for bridgework

Answer 3

un-coperative patients
MH contraindications
poor oh
high caries rate
perio disease
large pulps
tilting and rotation of teeth
perioapcal status ad perio status
degree of restoration (how much tooth is left after prep)

Question 4

Abutment

Answer 4

a tooth which serves as an abutment for a bridge

Question 5

pontic

Answer 5

the artificial tooth which is suspended from the abutment tooth

Question 6

retainers

Answer 6

the extra or intra coronal resotrations that are connnected to the pontic and cemented to the prepared abutment teeth

Question 7

connectors

Answer 7

component which connects pontic to the retainer

Question 8

edentulous span

Answer 8

space between natural teeth that is to be filled by a bridge or partial denture

Question 9

saddle

Answer 9

area of the edentulous ridge over the pontic will lie

Question 10

pier

Answer 10

an abutment tooth which stand between and is supporting 2 pontics, each pontic being attached to a further abutment tooth

Question 11

unit

Answer 11

either a retainer or a pontic (bridge with 2 retainers and 1 pontic = 3 unit bridge

Question 12

Fixed fixed bridge

Answer 12

retainer each end with pontic in middle joined by rigid connnectors

Question 13

advatnages of fixed fixed bridge

Answer 13

robust design
max retention and strength
can be used in longer spans
ab construction straightforward

Question 14

disadvantages of fixed fixed bridge

Answer 14

prep difficult
prep must be minimally tapered
common path of insertion for abutments
removal of tooth tissue (danger to pulp)

Question 15

Cantilever bridge

Answer 15

pontic at one end only - the pontic may be connected to one or more retainers

Question 16

Advantages of cantiliver bridge

Answer 16

lab construction straightforward

no need to ensure multiple tooth preps are parallel

Question 17

Disadvantges of cantilever bridge

Answer 17

short span only
rigid to avoid distortion
mesial cantilever preferred

Question 18

Fixed movable bridge

Answer 18

rigid connector usually at distal end of pontic and movebale connector mesially

Question 19

Advantages of fixed moveable bridge

Answer 19

prep don’t require a common path of insertion
more conservative of tooth tissue
allows minor tooth movement
may be cemented in 2 parts

Question 20

Disadvatages of fixed movable bridge

Answer 20

length of span limited
lab construciton complciated
possible difficulty in cleaning beneath movable joint
can’t construct provisional bridge

Question 21

Spring cantilever bridge

Answer 21

one pontic attached to end of metal arm that run across the palate to a rigid connector on the palatal side of retainer

Question 22

advantages of spring cantiliver bridge

Answer 22

useful if spacing between upper incisors
where adjacent teeth are unresotred
where a posterior tooth would provide a suitable abutment

Question 23

disadvatnages of spring cantilever bridge

Answer 23

can only be used to replace upper incisor teeth
diffcult to clean beneath paltal connector
may irritate the palatal mucosa
diffiuclt to control movement of pontic due to springness of metal arm and displacement of palatal soft tissues

Question 24

Abutment eva;uation

Answer 24

must be able to withstand forces previosuly dirrected to missing teeth
supporting tissues should be healthy and free of inflammation - e.g perio
crown to root ratio - length of tooth coronal to alveloar crest comapred to length of root embedded in bone - optimum ratio = 2:3

Question 25

Advantages of adhesive bridgework

Answer 25

minimal or no prep
no anaesthetic needed
less costly and less surgery time
can be used as provionsal resotoration

Question 26

disadvantages of adhesive bridgework

Answer 26

rigorous clinical tech
metal shine through
can debond
occusal interfence
no trial period possible

Question 27

Indications of adhesvie bridgeowork

Answer 27

young teeth 
good enamel quality 
large abutment tooth surface area
minimal occlusal load
good for single tooth replacement

Question 28

Contraindications of adhesive bridgework

Answer 28

long spans
insufficient or poor quality enamel
excess soft or hard tissue loss
poorly aligned, tilted or spaced teeth

Question 29

Stages of treatment of tooth for bridgework

Answer 29

1. prohylaxis
2. isolate with dental dam
3. etch, wash, dry
4. apply primer for 30 secs
5. air dry
6. fit adhesive bridge retainer to abutment tooth
7. remove excess cement
8. oxygen inhibitor placed around cement margins for 3 mins and wash off

Question 30

Function of a pontic

Answer 30

restore appearance of missing teeth
stabilise the occlusion
improve masticatory function
Should always be smooth with highly polished or glazed surface
embrasure space should be smooth and clneasable

Question 31

Wash through pontic dseign

Answer 31

makes no contact with soft tissue

cosndier in lower molar region

Question 32

dome shaped (torpedo or bullet shaped) pontic design

Answer 32

useful in lower incisors, premolars or upper molar areas

acceptable if occlusal 2/3rds of buccal surface visbible

Question 33

modified ridge lap pontic design

Answer 33

buccal surface looks like tooth as much as possible
lingual surface cut away
line contact with buccal of ridge
problems with food packing on lingual surface of bridge
moderate - low smile line anteriors

Question 34

Ridge lap/ saddle pontic deisgn

Answer 34

greatest contact with soft tissue
less food packing than ridge lap
care taken not to displace soft tissue or cause blanching of tissue
high smile line anterior and long span anteriors

Question 35

Materials used for bridges

Answer 35

all metal - gold 
metal ceramic 
lava 3M ESPE
Zirconia 
Implant retained bridges