Download RPD Framework Adjustment

Removable Partial Denture
Framework Adjustment
• Rudd & Kuebker
– 75% of frameworks don’t fit perfectly
– Active - orthodontic movement
– Adjust to make passive
Framework Adjustment
• Adjust without denture base
• Adjust soon after fabrication
– Prevent tooth migration
Video: Framework Adjustment
Clinical Adjustment
• Incomplete seating
• Usually binding on abutments
• Use an indicating medium
Incomplete seating
Indicating Medium
• Aerosol Sprays (Occlude)
• Disclosing Wax
• Silicone
Two-Dimensional Indicating Medium
• Occlude (aerosol)
– Thin & accurate
– Not easily displaced
– Can dissolve in saliva
– Difficult to remove
– Can’t tell how far from seating
Three-Dimensional Indicating Medium
• Disclosing Wax
– Sets immediately
– Inexpensive
– Shows how far from seating
– Can stick to teeth
– Can be distorted
Adjustment with
Silicone Indicating Medium
• Three dimensional
• Minimal distortion
• More expensive
• Sets relatively slowly (~1-2 min)
• Can tear or pull off the framework
Framework Adjustment
• Initial Assessment
• ‘How does the framework feel?’
• No pulling or wedging
– Active engagement of abutment teeth
• Overall comfort of the framework
Framework Adjustment
• Areas of abrasion on master cast
may indicate areas of binding
Check Maxillary Beading
• Ensure not binding on bony midline
• Can cause entire framework not to seat
• Use PIP to check
• Will burn through if
excessive height
Beading
Cautious Adjustment
• Differentiate between normal
& abnormal contacts
• Guiding planes
– normal: long vertical areas of
contact
– broad areas of severe burnthrough may indicate binding
Cautious Adjustment
• Avoid excessive force - bending
• Heat generation could melt acrylic
• Retentive tip of direct retainers
– normal: burn-through
– eliminate active clasp retention
Remake Poor Castings
• Determine if casting fits similarly on the
cast and intraorally
• If not, final impression inaccurate
• Make new impression
Framework
Occlusal Adjustments
• Fabricated on unmounted casts
• Occlusal interferences usually present
• Occlusal vertical dimension should be
unchanged
• Centric & eccentric contacts should be identical
with or without framework
Framework
Occlusal Adjustments
• Highly polished metal
–
Articulating paper marks poorly
–
Check opposing occlusal contacts
–
Slightly roughen framework with air abrasive or
rubber impregnated abrasive
Opposing Frameworks
• Adjust individually
• Then adjust together
• Eliminate interferences
between the frameworks
Occlusal Rest Thickness
• If ≤ 1.5 mm after adjustment
–
Subject to fatigue
–
Possible fracture
• May require additional tooth preparation & remake
• Last resort - occlusal reduction of opposing teeth
Interferences on Retentive Arms
• Minor interference
– Reduce opposing cusp - last resort
• Heavy contact
– Lower height of contour, remake
• Don’t relieve
– Alters flexibility & fracture
resistance
Physiologic Relief
• Used for Class I & II w. long g.p.
• Normally shorter guiding planes
– Triangular space below height of contour
– Allow for release
• Tipped teeth may only provide for long
guiding planes (low h of c)
Physiologic Relief
• Distal Extension Cases
– Guiding planes, minor
connectors & lingual plates
coated with indicator
– Framework is placed in
hyperfunction by pressing over
gridwork
Physiologic Relief
• Relieve burn-through
– Until burn-through occurs only on the
occlusal one third of the guiding
planes
Physiologic Relief Alternative
• Prescribe 1° relief
OR
• Use physiologic relief, not both