Prostho Final Lec2

7/30/2019 Prostho Final Lec2

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Dr. Louie Hammad

Metal Framework Try IN

-Its a very important issue for you as a dentist so please be aware.

-You know that you need to take a primary impression, send it to the lab

then you will get primary cast you will make surveying on it and make

the design, you take the 2nd

impression send it again to the lab to make

secondary or master cast.

-In the lab they do the wax-up similar to your design then process it to get

metal framework part

-What we should do after delivering the metal framework from the lab?

The metal framework should be fitted to the mouth shortly after itis returned from the dental laboratory.

(If you try it after long time you maybe surprise bcz there is

movement of the teeth or changes in the vertical dimension)

The practitioner must ensure that each framework fits extremelywell

Must be completely passive in the mouth. That mean you shouldfeel there is retention BUT there isnt any excessive lateral force on

the abutment teeth.

-In (A) its a good fitting framework on this

tooth; the clasp and the reciprocating arm

are fitting in its true place. BUT in (B) they

arent in their true space that means we will

end with lateral force affect the tooth, with

time it may lead to periodontal problems

and may cause bone resorption, and the

patient may lose this tooth bcz of mal-fitting

of the clasp on this tooth


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Dr. Louie Hammad :NOTEs*

-Before you try in the framework you should make sure that every thing

is ok.

1-recieve the metal framework from the

lab

2- Examine the metal framework

on theTry in the metal framework-3

firstmaster cast

4- Then Try in the metal framework in

the patient mouth

*Examination of the metal Framework:

-Was the proposed design closely followed?* You should make sure that the design which you receive is the same

that you make (the technician should follow your design) and each part of

the metal framework should be in its true place.

-After you check the metal frame work you will try it on the master cast,

(framework should fit tightly against the master cast)

-If everything is good until now, then you can try in patient mouth butbefore that chick it by your hand and fingers:


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Dr. Louie Hammad

*** You should follow the following steps ***

1. Are the rests fully seated in their preparations?


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Dr. Louie Hammad 2. Are reciprocal clasp arms and/or lingual plating in intimate contact

with tooth surfaces?

3. Have finishing and polishing procedures been carried out correctly?

-We polish the polishing surface, the surface away from the tissue to

.prevent food & plaque formation


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Dr. Louie Hammad 4. Is the major connector sufficiently rigid?

-To make sure for the rigidity of the major connector, you hold it and try

to bend it by your fingers, if it bends easily that mean its a failure one

and you should repeat it.

****NOW TRY IT IN PATIENT MOUTH: ****

*Clinical Procedures

-Now bcz of present of saliva and other component in the mouth, its

difficult to try in so, you can use

Disclosing media.-You can spray or apply it on the fitting

surface of the metal framework then you

try in the patient mouth, if there is any

point prevent it to fit then the disclosing

material will remove from its place So

its easy to use it BUT its a messy

.material when it contact with saliva it dissolve

wax disclosingYou can also use a-

its give you 3D presentationmedia

(height, width and depth of the

contacting point)

you soften itIn this pic you notice that-

hethen you apply it as a thin layer on t

fitting surface


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Dr. Louie Hammad Make sure that you apply theThen you put it in the patient mouth.-

. Bcz now there is nothingpressure on the rest not on the saddle area

under the saddle area and there is a space for the acryl so, if you press it

then you end with false pressure area (removed disclosing media).

-After removing the metal framework from patient mouth you notice

some metal shown. So gently you can use several burs to remove the

excess metal and polish and smoothen it

-After that you will put a new layer of disclosing material and try it again

until you have a continuous layer.

The most common area that prevents the metal framework to fit in:Note*

its place is:

1- The root of the clasp at the sides of the rest.2- The proximal part of the metal framework.

-The guide plane should fit passively in its placeit shouldnt apply any

pressure on the tooth. You can remove and apply it without harming the

tooth.


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Dr. Louie Hammad


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Dr. Louie Hammad


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Dr. Louie Hammad


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Dr. Louie Hammad


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Dr. Louie Hammad

*Now if everything is good you can do some opposing occlusion, to

make sure that the metal framework is not interfering with the opposing

. Chick centric and eccentricarticulator paperdentition. Its done by

occlusion.

-If you have both upper and lower metal framework, you should startwith upper and do the occlusion correction then continue with the lower,

then you put both of them and chick the occlusion.


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Dr. Louie Hammad


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Dr. Louie Hammad

**IMPORTANT NOTES:

1) The reduction from the metal should notless than 1 mm.

2) Corrective grinding procedures shouldalways be performed with great care.

3) Practitioner must avoid overcutting themetal surfaces.

4) Thickness of the rest should be 1-1.5 mm.5) To measure the thickness of the metal

framework you can use the metal gauge.

Documents

Prostho Final Lec2