BDS4 dickie bridges Flashcards
indications bridges?
- Function and stability
- Appearance
- Speech
- Psychological reasons
- favourable abutment angulation
- favourable occlusion
contra-indications bridges?
- Poor oral hygiene
- High caries rate
- Periodontal disease
- Large pulps (conventional bridge)
- uncooperative pt
- Prognosis of abutment poor
- Length of span too great
- Degree of restoration (how much of tooth is left after preparation)
what is retainers?
The extracoronal or intracoronal restorations that are connected to the pontic and cemented to the prepared abutment teeth
what is a pier?
An abutment tooth which stands between and is supporting two pontics, each pontic being attached to a further abutment tooth
what is a unit? and for example what would a bridge with 2 retainers and one pontic be?
Either a retainer or a pontic
- e.g. A bridge with two retainers and one pontic = 3 unit bridge
what are types of bridge designs?
conventional or adhesive/resin retained
- fixed-fixed
- cantilever
fixed moveable bridge
hybrid bridge
spring cantilever bridge
what is a cantilever bridge?
This type of bridge has a retainer (or retainers) at one side of the pontic only
- can be either conventional or adhesive/resin retained
what is a fixed-fixed bridge?
This type of bridge has a retainer at each end with a pontic in the middle joined by rigid connectors.
- can be either conventional or adhesive/resin retained
what are advantages of resin bonded bridgework?
- Minimal or no preparation
- Less costly
- Less surgery time
- Can be used as a provisional restoration
what are disadvantages of resin bonded bridgework?
- Metal shine-through
- Chipping pocelain
- Can debond (High chance of it debonding again)
- Occlusal interferences
- No trial period possible
what are indications for resin bonded bridgework?
- Young teeth (Less destructive)
- Good enamel quality
- Minimal occlusal load
- Good for single tooth replacement
what are contraindications for for resin bonded bridgework?
- Insufficient or poor quality enamel
- Long spans
- Heavy occlusal force e.g. Bruxist
- Poorly aligned, tilted or spaced teeth
what must you do with study models for resin bonded bridgework and what may you consider
- mounted on semi-adjustable articulator with facebow registration
- may consider diagnostic wax-ups
when to use a direct resin bonded bridge?
- Very useful in emergency situation
- If tooth needs to be extracted immediately
- If tooth has been lost traumatically
what are considerations in regards to existing restorations in abutment teeth?
- firstly need sound enamel
composite - ok but might need to consider replacing prior to prep
amalgam - compromised bond to chemically cured composite cement so consider replacing
what is supra gignival chamfer finish line for bridge?
0.5mm
how do you do a minimal prep anterior preparation?
- Occlusal contact reduction,
- Cingulum undercut removal only
- Chamfer margin (0.5mm supra-gingival)
how do you do a heavier preparation anterior prep?
0.5mm palatal reduction(NOTE – metal retainer wing should be 0.7mm thick)
Cingulum rest
+/- Proximal grooves
Chamfer margin (0.5mm supra-gingival)
how do you do posterior preparation?
- Occlusal rests
- 180º wrap-around with chamfer finish line (0.5mm supra-gingival)
- +/- Proximal grooves
why must you fit bridge as quickly as possible?
Minimise over-eruption and tooth movement
what is treatment of retainer?
try in
- fit and aesthetics
chairside micro-etching with 50 micron aluminium oxide particles (sandblast)
- should have been done by technician
clean retainer
- ultrasonic bath if required
- use ethanol to ‘degrasse’ if required (reduced surface tension)
apply chemically (or dual cure) cure composite luting cement just prior to placement of restoration after tooth treatment
how would you go about the treatment on the tooth prior to placing retainer?
- Prophylaxis
- Isolate with dental dam
- Etch tooth: 37% ortho-phosphoric acid (some preparations are 40%)
- Wash & dry
- Apply primer (A and B mixed together) for 30 seconds
- Air dry for 2 seconds
- No need to cure (unlike for direct composite restorations)
after treatment of tooth what do you do?
Fit retainer (coated with luting cement) to abutment tooth/teeth
Remove excess cement
Oxygen inhibitor (Oxyguard II) placed around cement margins for 3 minutes
- Wash off
what do you do post-cementation?
check occlusion
- confirm pontic does not have excessive occlusal forces applied
demonstrate to patient how to clean around and underneath the bridge
- superfloss
- interdental brushes