Technique Overview

7/30/2019 Technique Overview

1/41

Making Millions Smile

Flexib i l i ty is our Streng th


2/41

Valplast Flexible Partials

Lab Techniques for

Flexible Partial Dentures


3/41

Introduction to Flexible Partials

Simple solution to provide a removablerestoration

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


4/41

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

temperature (making it both flexible andsturdy)

In use since 1953


5/41

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


6/41


7/41

Visually Survey Model

Visualize design

Aesthetics

Path of Insertion

Comfort

Accuracy of Model

Remove Discrepancies


8/41

Wrap-Around Clasp

Most CommonClasp

Hugs Tissue

Minimal Coverage ofTooth

Stability againstvertical and

rotational movement

Design is made with Red Pencil


9/41

Split Wrap-Around

Clasp Separated fromFlange

Similar to Roach

Clasp Flexibility along

Horizontal and

Vertical Axes


10/41

Spur


11/41

Anchor


12/41

Maxillary Wax Relief

Relief Wax placedalong Buccal

Periphery

Necessary on AllMaxillary Cases

Use Hot Wax for Relief


13/41

Mandibular Wax Relief

Junction of clasp withsaddle is more rigid

area.

Undercut towardperiphery must berelieved


14/41

Blocking and Relieving

Lingual UndercutsRelieved

InterproximalSpaces Closed

Obstructive

Undercuts Removed


15/41

Final Preparation

Beading Post Dam

Etching Design


16/41

Duplication

Soak Model

Prepare Flask

Pour Gel

Let set 15 minutesin air

and 15 minutesin water


17/41

Waxing After Setup

Use of PrefabricatedForms is

Recommended to

Insure ProperThickness and

Uniformity


18/41

Palatal Waxing

Soften Palate

Press to Position

Seal all Borders


19/41

Buccal Waxing

Using Prefabricated Form:

Cut Form to Size

Press to Model

Seal all Borders


20/41

Bottom Half Investing


21/41

Spruing


22/41

Top Half Investing


23/41

Top Half Investing


24/41

Teeth Prepared for

Retention


25/41

Processing


26/41

Melting - 11 Minutes


27/41

Injecting


28/41

Lets See That Again...


29/41

After Processing


30/41

Pre-Finishing

Econo-

CutterTrimmer

Dark

GrindingWheels


31/41

Fitting and

Rubberizing

Brown

Rubber

Wheels

Vulcanite

Burs


32/41

Polishing


33/41

Polishing Motion is

Important


34/41

Advising Clinician on Insertion

and Adjustment

Partial must be placed in very hot water(150F 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


35/41

Adjustments

Minor clasp tightening or loosening can be doneby heating the clasp again in very hot water and

bending it severely in the needed direction. This

will purposely warp the area enough to changeits position

Grinding should be done as a last resort.

Use a Standard Green Mounted Stone (usedusually for porcelain) to adjust Valplast. 20K to

30K rotation and constant motion


36/41

Small Additions - Welding

Using hot air welder and welding rod, build up aboxing 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 tooth-shade or pink acrylic.


37/41

Large AdditionsInjection

Wax new section on duplicate model tooriginal partial

Invest, Sprue, Wash out wax

Prepare bonding site with acid etchsolution (Val-Fuse Repair Liquid)

Inject, finish, and polish


38/41

Relines

Take Putty Matrix to record tooth position Strip teeth from partial (in blocks) while

duplicating the model.

Rewax new base using matrix to positionteeth

Invest and process using repair technique

to bond top-half exposed Valplast to newbase.

Finish and Polish


39/41

Clinical Prep for Tooth

Addition

Clinician should take overall alginateimpression to lift out case

Counter-model for bite

Before pouring the model, any deposits oradhesives should be removed from

surface or the process will lead to an

unintended reline.


40/41

Clinical Prep for Reline

Closed-mouth rubber-base relineimpression.

Pick-up overall alginate impression.

Counter not necessary


41/41

Documents

Technique Overview