Bridgework Flashcards
What is a bridge?
a prosthesis which replaces a missing tooth/ teeth and is attached to one or more teeth
Indications for bridgework
Function and stability speech psychological reasons Systemic diseases - e.g epiletics co-operative patients
Contraindications for bridgework
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)
Abutment
a tooth which serves as an abutment for a bridge
pontic
the artificial tooth which is suspended from the abutment tooth
retainers
the extra or intra coronal resotrations that are connnected to the pontic and cemented to the prepared abutment teeth
connectors
component which connects pontic to the retainer
edentulous span
space between natural teeth that is to be filled by a bridge or partial denture
saddle
area of the edentulous ridge over the pontic will lie
pier
an abutment tooth which stand between and is supporting 2 pontics, each pontic being attached to a further abutment tooth
unit
either a retainer or a pontic (bridge with 2 retainers and 1 pontic = 3 unit bridge
Fixed fixed bridge
retainer each end with pontic in middle joined by rigid connnectors
advatnages of fixed fixed bridge
robust design
max retention and strength
can be used in longer spans
ab construction straightforward
disadvantages of fixed fixed bridge
prep difficult
prep must be minimally tapered
common path of insertion for abutments
removal of tooth tissue (danger to pulp)
Cantilever bridge
pontic at one end only - the pontic may be connected to one or more retainers
Advantages of cantiliver bridge
lab construction straightforward
no need to ensure multiple tooth preps are parallel
Disadvantges of cantilever bridge
short span only
rigid to avoid distortion
mesial cantilever preferred
Fixed movable bridge
rigid connector usually at distal end of pontic and movebale connector mesially
Advantages of fixed moveable bridge
prep don’t require a common path of insertion
more conservative of tooth tissue
allows minor tooth movement
may be cemented in 2 parts
Disadvatages of fixed movable bridge
length of span limited
lab construciton complciated
possible difficulty in cleaning beneath movable joint
can’t construct provisional bridge
Spring cantilever bridge
one pontic attached to end of metal arm that run across the palate to a rigid connector on the palatal side of retainer
advantages of spring cantiliver bridge
useful if spacing between upper incisors
where adjacent teeth are unresotred
where a posterior tooth would provide a suitable abutment
disadvatnages of spring cantilever bridge
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
Abutment eva;uation
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
Advantages of adhesive bridgework
minimal or no prep
no anaesthetic needed
less costly and less surgery time
can be used as provionsal resotoration
disadvantages of adhesive bridgework
rigorous clinical tech metal shine through can debond occusal interfence no trial period possible
Indications of adhesvie bridgeowork
young teeth good enamel quality large abutment tooth surface area minimal occlusal load good for single tooth replacement
Contraindications of adhesive bridgework
long spans
insufficient or poor quality enamel
excess soft or hard tissue loss
poorly aligned, tilted or spaced teeth
Stages of treatment of tooth for bridgework
- prohylaxis
- isolate with dental dam
- etch, wash, dry
- apply primer for 30 secs
- air dry
- fit adhesive bridge retainer to abutment tooth
- remove excess cement
- oxygen inhibitor placed around cement margins for 3 mins and wash off
Function of a pontic
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
Wash through pontic dseign
makes no contact with soft tissue
cosndier in lower molar region
dome shaped (torpedo or bullet shaped) pontic design
useful in lower incisors, premolars or upper molar areas
acceptable if occlusal 2/3rds of buccal surface visbible
modified ridge lap pontic design
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
Ridge lap/ saddle pontic deisgn
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
Materials used for bridges
all metal - gold metal ceramic lava 3M ESPE Zirconia Implant retained bridges
