Flexibility is our Strength Making Millions Smile™

Flexibility is our Strength
Making Millions Smile™
Valplast® Flexible Partials
Lab Techniques for
Flexible Partial Dentures
Introduction to Flexible Partials
• Simple solution to provide a removable
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restoration
No tooth preparation needed
No metal frame needed
Finished partial with one trip through the
laboratory
Injection Technique
Valplast Partials are repairable and relinable
Guaranteed not to break
Type of Material
• Valplast is a type of Nylon Thermoplastic
• Injection Molded
• Denser than acrylic
• Lower Water Absorption than PMMA
• Flexural modulus around 470MPa at body
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temperature (making it both flexible and
sturdy)
In use since 1953
Lab Procedure - Overview
• Design, block and relieve master model
• Duplicate stone model
• Try-in (if required) or Set-up on Master
• Transfer set-up to duplicate model
• Wax with prefabricated patterns
• Invest, Sprue, Wax Elimination
• Process with Manual Injector
• Finish and Polish
Visually Survey Model
• Visualize design
• Aesthetics
• Path of Insertion
• Comfort
• Accuracy of Model
Remove Discrepancies
Wrap-Around Clasp
• Most Common
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Clasp
Hugs Tissue
Minimal Coverage of
Tooth
Stability against
vertical and
rotational movement
Design is made with Red Pencil
Split Wrap-Around
• Clasp Separated from
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Flange
Similar to “Roach”
Clasp
Flexibility along
Horizontal and
Vertical Axes
Spur
Anchor
Maxillary Wax Relief
• Relief Wax placed
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along Buccal
Periphery
Necessary on All
Maxillary Cases
Use Hot Wax for Relief
Mandibular Wax Relief
• Junction of clasp with
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saddle is more rigid
area.
Undercut toward
periphery must be
relieved
Blocking and Relieving
• Lingual Undercuts
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Relieved
Interproximal
Spaces Closed
Obstructive
Undercuts Removed
Final Preparation
• Beading Post Dam
• Etching Design
Duplication
• Soak Model
• Prepare Flask
• Pour Gel
• Let set 15 minutes
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in air…
…and 15 minutes
in water
Waxing After Setup
• Use of Prefabricated
Forms is
Recommended to
Insure Proper
Thickness and
Uniformity
Palatal Waxing
•Soften Palate
•Press to Position
•Seal all Borders
Buccal Waxing
Using Prefabricated Form:
•Cut Form to Size
•Press to Model
•Seal all Borders
Bottom Half Investing
Spruing
Top Half Investing
Top Half Investing
Teeth Prepared for
Retention
Processing
Melting - 11 Minutes
Injecting
Let’s See That Again...
After Processing
Pre-Finishing
EconoCutter
Trimmer
Dark
Grinding
Wheels
Vulcanite
Burs
Fitting and
Rubberizing
Brown
Rubber
Wheels
Polishing
Polishing Motion is
Important
Advising Clinician on Insertion
and Adjustment
• Partial must be placed in very hot water
(150°F or more) for a minute prior to
insertion and allowed to cool to a tolerable
temperature.
• This process makes the partial as flexible as it
would be at body temperature. This
minimizes adjustments
Adjustments
• Minor clasp tightening or loosening can be done
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by heating the clasp again in very hot water and
bending it severely in the needed direction. This
will purposely warp the area enough to change
its position
Grinding should be done as a last resort.
Use a Standard Green Mounted Stone (used
usually for porcelain) to adjust Valplast. 20K to
30K rotation and constant motion
Small Additions - Welding
• Using hot air welder and welding rod, build up a
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boxing in the addition site to secure a new tooth
Select a matching acrylic tooth.
Break a porcelain tooth to obtain pins
Heat each of two pins in flame to cherry red and
embed in the partial half way (pin head
protruding)
Cure scooped stock tooth over pins using toothshade or pink acrylic.
Large Additions – Injection
• Wax new section on duplicate model to
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original partial
Invest, Sprue, Wash out wax
Prepare bonding site with acid etch
solution (Val-Fuse Repair Liquid)
Inject, finish, and polish
Relines
• Take Putty Matrix to record tooth position
• Strip teeth from partial (in blocks) while
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duplicating the model.
Rewax new base using matrix to position
teeth
Invest and process using repair technique
to bond top-half exposed Valplast to new
base.
Finish and Polish
Clinical Prep for Tooth
Addition
• Clinician should take overall alginate
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impression to lift out case
Counter-model for bite
Before pouring the model, any deposits or
adhesives should be removed from
surface or the process will lead to an
unintended reline.
Clinical Prep for Reline
• Closed-mouth rubber-base reline
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impression.
Pick-up overall alginate impression.
Counter not necessary