Trimming Guide

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WEHMERStudy Model Trimming Guide

Trimming Tips

Before you start trimming, here's a few guidelines that will help you get the most out

of your trimming procedures -

Always follow the plaster manufacturers mix ratio for plaster and water. Consistent,measured mix ratios minimize shrinkage and maximize material strength.

Always mix your plaster or stone under vacuum, and pour while vibrating to avoid

air bubbles.

When pouring your model, make sure that the bottom of the impression tray, the occlusal surface of the impres-

sion, and the bottom of the base former (or "boat") are all parallel. Otherwise you'll start off with the teethon an angle, and you'll have to compensate by removing lots of material from the base.

Soak your models in water for 5-10 minutes. This will eliminate the heavy plaster slurry on the model and

trimming table caused by the model absorbing water as you're trimming.

If using stone wheels, turn on the trimmer and the water flow at least one minute before starting to grind plaster.

This will allow the wheels to get "conditioned" by water flow and grind to their maximum capability.

Let the wheels to do the cutting. Excessive force in pushing the model onto the wheel "squeezes out" thewater from between the model and the abrasive, causing the wheel to clog - further reducing cutting capability.

Excessive force also slows down the speed of the motor, reducing its efficiency and creating premature wear onmechanical components. If you need to really lean on your wheel, it's time to replace it.

You'll achieve your best results and finish by moving the model back and forth across the wheel as you're grind-ing, and by using gentle, but firm pressure.

Trimming Technique

Upper ModelBefore beginning to trim, occlude the upper and lower models with the wax bite in place, and check the relationship ofthe last molars to each other. If the molars of the lower model extend significantly further than the molars of the upper

model, add the distance of the extension to the 5 mm distance in step 3. Also, if any plaster interferes with the modelsfully occluding, remove it at this time with a lab knife.

Step 1 Mark a light pencil line down the midline suture of the model for reference.

Coarse trim heel of upper model enough to square it to the midline.

Step 2 Occlude upper model on rubber pad of squaring tool and take a swipe with the

coarse wheel to establish a flat surface on the base - parallel to the plane ofocclusion. Thickness of the model from base to occlusal surfaces should be

about 38 mm(1 1/2"). If it's larger, occlude the model to the squaring tool andreduce base to proper size.

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Step 3 Place the freshly trimmed base on the trimming table and trim the heel of the

model parallel to an imaginary line running between the distal surfaces of the

last molars and perpendicular to your midline pencil mark. Make this cut to within5 mm (3/16") from the last teeth in the arch.

Step 4 Trim away any excess material around the periphery of the base at this time. Trimto within 12mm (1/2") from the buccal surfaces of the teeth.

Step 5 With the heel of the model against the angulation tool, trim the front of the model25 degrees to the left and right to meet at the anterior midline, approximately 7mm

from the teeth.

Remember, it is important that on all trimming procedures , anatomy exten-sions should be equidistant around the entire arch for both models!

Step 6 Now, set the angulation tool to 65 degrees and trim the right and left sides of the

model to within 7 mm of the teeth.

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Lower Model

Step 7 Rough-trim excess material around periphery of model, including flattening of theheel parallel to distal surface of the last molars.

Step 8 Occlude the lower with the upper model using the wax bite, and trim the bottom of

the lower base to a total thickness of 3 for the two models.

Step 9 With wax bite in place, trim backs of model parallel until wheel just makes con

tact with the heel of the upper model. If wax protrudes past last molars, trimaway with lab knife before grinding to avoid clogging of the wheel.


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Step 10 With models still occluded, trim heel corners to 115 degrees.

Step 11 Now, set the angulation tool at 55 degrees and trim the right and left hand sides

of the model, maintaining the same amount of anatomy extension as on theupper model.

Step 12 Place the heel of the lower model against the unlocked angulation tool and trim a

3-3 cuspid roll to about 7 mm from the anterior teeth.

Step 13 Lightly touch all trimmed surfaces of both models on the fine wheel until heavyscratches are removed.

Step 14 All art work, sculpting, and repairs can now be done prior to soaping and finish-ing the completed models.



WEHMERStandard Diamond Trimming WheelReplace your stone or sticky back wheel with the convenience andefficiency of diamond abrasives. 30% improved cutting speed andover 20 times the wear. Available in 12 and 10 coarse. Pleasespecify make and model of trimmer.

WEHMERPrime Cut Trimming WheelThe ultimate in trimming technology. Premium stainless steelbacking is precision balanced and provides superior bonding ofabrasive.Single-sided wheel is available in 12 size only - Coarseand Fine grit. Please specify make and model of trimmer.

12 Coarse Order Code: 1150



12 Fine Order Code: 1155

The single, most significantupgrade you can make toyour modeltrimmer!

Solid Stainless Steel.Precision balanced andtrued.


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WEHMERTUF-STTUF-STONONWhite Orthodontic Stone

Low expansion stone with brightening additives

makes tough and rugged models for diagnosisand appliance fabrication. Easy mixing and

smooth pouring. 13-15 minute initial set time.

Compressive strength at 9000 PSI.

Order Code: 6710

Order Code: 6711

Order Code: 6720

Order Code: 6721

WEHMERPUR-WHITEPUR-WHITEOrthodontic PlasterCreamy to mix and smooth to pour, this plaster has

extra brightening additives to make your studymodels extremely white. Manufactured in a sepa-

rate facility from other gypsum products,WEHMER PUR-WHITEPUR-WHITE has less potential envi-

ronmental particulates to cause black marks inyour models. 13-15 minute initial set time.

Compressive strength at 6500 PSI.

25 Lb carton

50 Lb carton 50 Lb carton

25 Lb carton

TTrry it. Yy it. Youll Like it!oull Like it!

Plaster Nipper

Order Code: 16405

Order Code: 16404

Order Code: 16402

Our choice for mixing plasterthese spatulas offer conven-ience and utility when mixinggypsum products.

Stainless Steel constructionfor corrosion resistance andlong life. A great tool forremoving bulk plaster fromthe cast.10R Large

8R Small

Spatulas

WEHMER Heavy-Duty Commercial-Grade Dual Wheel Model Trimmer.

The 108P offers 50% more horsepower than our standard model 108 plus a coarse diamond trim

ming wheel and the convenience of electric water flow control.This .75 HP trimmer cuts up to 30%faster than standard machines fitted with carborundum wheels, and wheel life is dramaticallyimproved (over 20 times). The 108P is delivered with Mylar orthodontic trimming table, squaringand angulation tools, built-in water spray system, and 3 drain hose. Add an optional work lightdrain tray, or splash guard to complete your PRO trimmer package.

Dimensions 21.5w x 18d x 15.5h (54.6cm x 46cm x 39.5cm)Wheel Size: 12 x 1 x 3/16

Shipping Weight: 73 Lbs.Specify 110 or 220 volt/ 50 or 60 Hz

The Top-of-the-Line in Single Wheel Ortho Trimmers.

Looking for a single wheel orthodontic model trimmer with superior performance characteristicsquality, and ease of use? When space is an issue, the 125OP fits the bill with power and precision

plus the work table and orthodontic tools that made our dual wheel trimmer the #1 choice for orthoapplications. With the 125OP, the 3/4 HP motor, #1150 coarse diamond trimming wheel and electronic water control are standard equipment. Increase your productivity while saving space with thisrugged machine.

Dimensions 15.5w x 18d x 17.5h (39.5cm x 46cm x 44.5cm)Wheel Size: 12 x 1 x 3/16

Shipping Weight: 56 Lbs.Specify 110 or 220 volt/ 50 or 60 Hz

The table and tools that made our dual wheel trimmer the standard for orthodontic studymodel grinding are now standard on our rugged and reliable single wheel ortho trimmer.

Order Code: 108P

Order Code: 125OP

Copyright 2003 by The WEHMER Corporation

Trimming Guide

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