Fixed Exam 1 - Framework Design Flashcards
Portion of a fixed dental prosthesis that unites the retainers and pontics
Connector
Which part of the bridge?
Strong, rigid (not brittle)
Framework
Which part of the bridge?
Function = support and marginal fit
Framework
Which part of the bridge?
Brittle
Overlaying ceramics
Which part of the bridge?
Function = esthetics (1mm minimum required)
Overlaying ceramics
Which part of the bridge?
Resistant to compressive load
Fragile under tensile stress
Overlaying ceramics
The overlaying ceramic should not exceed ______ mm to avoid fracture
2mm
The overlaying ceramic is highly polished/glazed to prevent what?
Wearing opposing dentition
What is the ideal amount of wear on the bridge per year?
10 um
Framework should allow an ________ porcelain thickness
even
Framework should NOT have an abrupt contour change between __________ and ___________
metal; porcelain
What type of occlusion?
More conservative prep, as thin as 1mm
Metal
What type of occlusion?
Stronger occlusal surface (may be indicated for bruxism)
Metal
What type of occlusion?
May be indicated when there’s limited interocclusal clearance
Metal
What type of occlusion?
Compromised esthetics - discuss w/ pt while tx planning
Metal
What type of occlusion?
For functional cusps, centric occlusal contacts should be in metal surface
Metal
What type of occlusion?
Functional cusps are 1.5mm away from interface
Metal
What type of occlusion?
For functional cusps, avoid eccentric movement contacts going over interface
Metal
T/F: Interproximal should be in either only metal or only porcelain
True
Ideally, interproximals should be in _________, because it will be easier to add material if there’s an open contact
porcelain
Where is plaque accumulation more common?
Interface
What type of bridge margin?
Excellent margin seal, preserves periodontal health
Metal collar
What type of bridge margin?
Distortion of framework is avoided during crown fabrication
Metal collar
What type of bridge margin?
Rigidity during cementation and function
Metal collar
What type of bridge margin?
Designed w/ a 0.5mm - 1mm collar
Metal collar
Which teeth are metal collars used for?
Posterior (due to esthetics)
What type of bridge margin?
Hairline collar, disappearing margin
Conventional
What type of bridge margin?
Metal and opaque porcelain layer meet simultaneously on the prep’s margin
Conventional
What type of bridge margin?
Deep chamfer (1mm) or shoulder is recommended to provide rigidity of the metal + esthetics
Conventional
What type of bridge margin has the following disadvantages?
Exposed opaque porcelain layer (esthetics)
Difficult finishing
Marginal adaptation may distort after firing
Conventional
What type of bridge margin has the following esthetic advantages?
Eliminates metal on margin
Depth in cervical translucency
Light transmission through the root
Butt
What type of bridge margin?
Commonly used on anteriors
Butt
What type of bridge margin has the following disadvantages?
Requires 1.2mm margin depth to achieve esthetics
Difficult to get marginal seal due to contraction of porcelain towards greatest bulk during firing
Butt
Agent applied to die to provide space for cement when cementing the restoration
Die spacer
What is the film thickness of the die spacer?
25-50 um
The die spacer is applied within ______ mm from the margin
1mm
What has the following materials?
Resins
Model paint
Thermoplastic polymers dissolved in volatile solvents
Die spacer
Name the 4 rigid connectors
Cast
Soldered
Welded
Loop
What type of connector?
Convenient; incorporated in wax pattern to minimize number of steps during fabrication
Cast connector
What type of connector?
Fit may be compromised due to distortion of wax
Cast
What type of connector?
Involves the use of an intermediate metal alloy with a lower melting point than the rest of the framework
Soldered
What type of connector?
Parts being joined don’t fuse, but must be wetted to obtain a successful soldering
Soldered
What type of connector?
Used when a framework doesn’t fit the abutments as a whole unit, but does as independent abutments
Soldered
What type of connector?
Adjacent surfaces/parts being connected are fused by heat or pressure
Welded
What type of connector?
A filler metal, with a similar melting temp as the framework
Welded
What type of connector?
Sometimes required when a diastema needs to be incorporated to a FDP
Loop
What type of connector?
Weak design, rarely used
Loop
What type of connector?
Consists of a loop on the lingual part of the FDP
Loop
What type of connector?
May be cast w/ rest of framework or shaped w/ a Pt-Au-Pd alloy wire
Loop
What type of connector?
One component goes inside another
Incorporated in the wax pattern fabrication stage
Non-rigid
What type of connector?
Rarely used now
Non-rigid
Name of female component of non-rigid connector
Mortise
Name of male component of non-rigid connector
Tenon
What type of connector?
Path of insertion must be same as the one of the FDP component w/ the tenon
Non-rigid
For non-rigid connectors, paralleling is usually accomplished with a __________
surveyor
What type of connector?
Overcomes different path of insertion of abutments
Non-rigid
What type of connector?
Segments large, complex FDPs into shorter components that are easier to replace/repair
Non-rigid
What type of connector?
Used where there is a questionable distal abutment
Non-rigid
What type of connector?
Relieves stresses on long FDPs
Non-rigid
What are the 3 ways non-rigid connectors can be prepared
Freehand (most difficult)
Precision machine
Pre-fabricated plastic patterns
What type of bridge?
Metal coping designed to correct the path of insertion of an abutment that is tilted (usually mesially); the coping is used as a retainer to fabricate the FDP
Telescopic crown
What type of bridge?
Can prevent over-preparing teeth and the need of endo
Telescopic crown
Telescopic crowns require an additional ______ mm of clearance to fit the additional metal coping
1mm
The fabrication of a _________ ________ is always required when treating a pt for a FDP where multiple abutments will be splinted
solid cast
Solid casts should be made from the _____ pour of the same final impression used to fabricate the master cast (1st pour = master cast)
2nd
T/F: The solid cast should NOT be pin indexed and sectioned
True
The lab tech uses this to verify the framework’s fit on a cast that has not been altered and has no removable components (master cast)
Solid cast
Precision between the abutment’s relationship is important to ensure a good _________ _________
marginal seal