Polishing partial denture frameworks

[Clear Precision Dental]

I know a lot of you do not fabricate RPD frameworks, however, I'm asking for some advice /help /ideas. I've outsourced my frames for the past 23 years, but now am getting nickled and dimed or I find that the labs I sent them to were sending them to China.

This is my new adventure, RPD frame fabrication. I finally got wise to dipping the refractory cast, wax-ups are much smoother now, and, thanks to the paint-on investment, the frames are casting nice [although sometimes the distal extension mesh does not always cast 100% - need more spruing?].

My question involves polishing the framework after casting and sandbasting. The metal is not real hard, but there is a heck-of-a-lot of square mm to polish! I was polishing similar to cast gold. It takes a while.

I invested in an electro-polishing unit (inexpensive but new). I had not seen it done so I was unsure of what to expect. My hope was that it would come out of the solution (Neoloy/Dentex) in 5 min all shiny and sparkly (like I receive it when I would outsource it to local lab who outsourced it to Taiwan). It was impressive to watch as it bubbled in the solution. When I removed it, however, it looked very clean but dull. Just like placing a nice gold casting in a hot pickling solution.

So I rubber wheel the thing again and finish with a rag wheel and Motloid's Dual-Lustre. I can get it shiny, but am I doin' it right?

I've not taken any classes on actual fabrication steps. I plan to go to a Bego course in the fall (still 6 mo's away). Until then I throw myself on the mercy of you fine folks. s ????????? Thanks.

 

[CYNOSURER]

Assuming it's all hooked up right, we leave a lower frame in for 6-7 minutes and and upper in about 7 - 8. The amperage should be about 4-5. Be sure the solution is heated to the right temp. Here's a pic of our set up. Found the jar in a Pier one type place. The jars that many polishers come with also come with a standard fish tank heater wich is way to tall for the jars (look for the 'water line' indicator on your heater. So, I bought this taller jar. I added the glass marbles simply to raise the 'bed' and not have to worry about using a ton of solution and having to heat it (the marbles hold heat better than the solution)

 

[Clear Precision Dental]

Thanks Tim ( I can always count on you!),

The marble idea is great. That is a keeper.

I need to check my amps. (Unit is new, so I was assuming it was correct).

My unit came with a ceramic croc, but it did not mention heating the solution. What is the "right" temp? The unit came with a timer. I tried 5 min, then I tried again for 10 min after reversing the polarity and the result was the same.

Do yours polish to the final state right out of the solution?

 

[CYNOSURER]

What is the "right" temp?

Should say on the solution. Mine is 120F not to exceed 160F which it will do if you do a lot in succession as the process generate heat.

Do yours polish to the final state right out of the solution?

As far as shine...75%. I still have to rubber wheel the scratches out and high shine.

 

[DDDental]

First of all,what kind of metal do you use?
Anyway, after electropolishing which should be in inexpensive machine for about 10 minutes in 45 degrees C, about 4-6 amps you should use Dedeco and only Dedeco Rubber wheels , starting with brown, then green and white, switching to rubber points, brown, then green. Here you can go over palate stipple with green rubber point, taking out any dull spots. Of course this is on High Speed metal grinder machine, do not try this on ordinary late. After that go to late and buy yourself blue Austenal 2 '' brushes and work with gray polishing compound ( Austenal)with water all over. Than work for a minute or so without compound and water. Go back to high speed and use green polishing compound (Austenal)with a hard felt wheel , switch to medium felt wheel, and you should be OK.
Sounds like a lot of work, but trust me, yes it is a lot of work to get good frame.

 

[TheLabGuy]

WORST JOB IN THE DENTAL LABORATORY INDUSTRY........has to be polishing Metal RPD's........you couldn't pay me enough, i'd rather do colonoscopy's all day......LOLOLOL

 

[sampson]

i agree - worst job
you cut your fingers on sharp edges
you spend (what seems like) all day polishing - green dust everywhere
then it turns out the dentist took a bad impression and frame has trouble fitting patient.

 

[Brian]

Casting could be one of 2? Either your not hot enough or your a little on the slow side and the alloy is chilling. Or it's your sprue. are you weighing the alloy correctly? Okay that was 3...

RPD's a re labor intensive.. Hope you have some hands or you only do a handful a month..

I say outsource! Give Jerry at Chrome Works a call 1-800-642-2278. Keeps your sanity and your fingers clean!

 

[CYNOSURER]

WORST JOB IN THE DENTAL LABORATORY INDUSTRY........has to be polishing Metal RPD's........you couldn't pay me enough, i'd rather do colonoscopy's all day......LOLOLOL

Amen! When I hired my deaf employee I thought, "Great, he won't mind the loud annoying high speed grinder." Couldn't even get him the least bit interested in it. Fortunately he has turned into a fine acrylic and Valplast finisher...even though Valplast can be just as nasty as metal with all the rubber wheeling and polish time.

 

[Clear Precision Dental]

Thanks for the info. Marbles and heat (will try this on the next one),and 75% shine - still need to polish for that final high-shine. I appreciate it.

DDDental, I'm using Wironit alloy.

Brian, I am using an induction casting machine with a fast spin setting. Since I am waxing directly onto the refractory cast, I cannot weigh my pattern to calculate specific gravity, so the amount of alloy I throw is a little bit of a crap-shoot. I've been playing with my sprue locations to get metal to zones but try to minimize areas that I have to cut back after cutting sprue attachments.


Thanks to all you smarties.

 

[CYNOSURER]

Weighing alloy doesn't really apply with partials. 90% of the time it's either a three or four ingots...I've never used the 'shot' metal.

Take a pic before you cut the sprues off next time and maybe we can 'see' something.

 

[DDDental]

Casting could be one of 2? Either your not hot enough or your a little on the slow side and the alloy is chilling. Or it's your sprue. are you weighing the alloy correctly? Okay that was 3...

RPD's a re labor intensive.. Hope you have some hands or you only do a handful a month..

I say outsource! Give Jerry at Chrome Works a call 1-800-642-2278. Keeps your sanity and your fingers clean!

Why not give a call to a fellow member DDDenal I am sure I can do as well as jerry 40000 frames and counting. [email protected].
Anyone from this forum will get one frame for free including shipping back just to mention DLN.
This is my little support to DLN members.

 

[TheLabGuy]

That's really cool.........thanks a bunch, the next metal RPD I'll send to you.

 

[kcdt]

RPD's are labor intensive.. Hope you have some hands or you only do a handful a month..

I say outsource! Give Jerry at Chrome Works a call 1-800-642-2278. Keeps your sanity and your fingers clean!

No kidding! I'm a one man show and the thought of that much added labor makes me want to stick a gun in my mouth. I feel I'm much better off with specialists who fabricate nothing but frames all day every day. It allows me to concentrate on the labor that gives me the best ROI and not make my life hell trying to master the occasional. Even if you have mastery of the technique, trying to pull off more than one dedicated production mode without the necessary extra hands is beyond the abilities of most.

 

[shirley]

Dental Treatment

Partial dental work may be opted by full dental implant or full teeth polishing.

 

[Clear Precision Dental]

Partial dental work may be opted by full dental implant or full teeth polishing.

Huh?

 

[DMC]

(Maybe he's talking about micro-polishing natural teeth to prevent bacteria's doo-doo from sticking??)

We're printing them'round here, partials that is, not doo doo.

BioDenTech, a neighbor of mine, bought two Sensable design stations and a 3D printer after seeing mine work. CAD partials with the ability to redesign and re-print if needed. Those will almost certianly never be milled out of a disk. Way too much milling. How about a Zirconia framework? Maybe a new, more flexible ceramic/hybrid material?? Almost clear/tooth colored material.

Keep your eyes open! Don't spend too much money on equiptment for that old skool way now, Um-K?

SensAble

 

[DDDental]

(Maybe he's talking about micro-polishing natural teeth to prevent bacteria's doo-doo from sticking??)

We're printing them'round here, partials that is, not doo doo.

BioDenTech, a neighbor of mine, bought two Sensable design stations and a 3D printer after seeing mine work. CAD partials with the ability to redesign and re-print if needed. Those will almost certianly never be milled out of a disk. Way too much milling. How about a Zirconia framework? Maybe a new, more flexible ceramic/hybrid material?? Almost clear/tooth colored material.

Keep your eyes open! Don't spend too much money on equiptment for that old skool way now, Um-K?

SensAble

Scott, CAD- CAM plastic frames still need to be invested, casted, finished and polished, which bring us back to the same question the man asked in the beginning.

 

[Kreyer]

I know a lot of you do not fabricate RPD frameworks, however, I'm asking for some advice /help /ideas. I've outsourced my frames for the past 23 years, but now am getting nickled and dimed or I find that the labs I sent them to were sending them to China.

This is my new adventure, RPD frame fabrication. I finally got wise to dipping the refractory cast, wax-ups are much smoother now, and, thanks to the paint-on investment, the frames are casting nice [although sometimes the distal extension mesh does not always cast 100% - need more spruing?].

My question involves polishing the framework after casting and sandbasting. The metal is not real hard, but there is a heck-of-a-lot of square mm to polish! I was polishing similar to cast gold. It takes a while.

I invested in an electro-polishing unit (inexpensive but new). I had not seen it done so I was unsure of what to expect. My hope was that it would come out of the solution (Neoloy/Dentex) in 5 min all shiny and sparkly (like I receive it when I would outsource it to local lab who outsourced it to Taiwan). It was impressive to watch as it bubbled in the solution. When I removed it, however, it looked very clean but dull. Just like placing a nice gold casting in a hot pickling solution.

So I rubber wheel the thing again and finish with a rag wheel and Motloid's Dual-Lustre. I can get it shiny, but am I doin' it right?

I've not taken any classes on actual fabrication steps. I plan to go to a Bego course in the fall (still 6 mo's away). Until then I throw myself on the mercy of you fine folks. s ????????? Thanks.

I designed and fabricated my own frames for over 20 years here is a link to the best electrpolish solution I found....
Esmadent Electropolishing Equipment and Ultrasonic Cleaning Systems and Equipment

 

[CYNOSURER]

You may be right Rob, but that is a classic case of a website un-selling a product. Man! want a pain to read and so little info.