Thermoplastic Acrylics

[drm313mac]

Andrew,

1. tcs: I then assume their set temperatures are not always equal to the actual temperatures?

Their hard nylon for full dentures is brand new. They are selling sample packs only, so far. Christina Posca quoted me $40 for a 5-pack, which heck, is dirt cheap. I told Isay @ Chase Dental I will try out 20 packs.

2. Regarding both tcs as well as Astron 1180 vinyls:
a. Yes, I know the vinyls are MORE hydrophilic. I am hoping the tcs is less so than the Astron/Luxene 1180.
b. Do we require stabilizer to Type-IV stone? Invested Type-IV is what we will use for all our model pours. It is smoother as well as more accurate (0.1% shrinkage).

3. Processor: I ordered the Astron Lab~Pro, but they were out with nothing new coming, and so direct (from Germany??) the Mestra M9 arrived.

I chose not to go with the Ivoclar due to incomplete polymerization. That is, @ the Hinman I had the opportunity of speaking with one of the engineers who developed both the Ivoclas as well as the IvoBase. With each system I see good and bad. The Ivoclas does not polymerize completely, and the engineer admitted this, which surprised me. The IvoBase takes 1 hour, so a production lab would need at least 10 of these, @ ~$8,800 each. OUCH.

Dentsply Success is Dentsply, with whom I chose not to do business when possible. Yes, I do get the X-tip from them, as I have no choice, but otherwise ...

 

[drm313mac]

1. WHY not? I will not heat IN the cylinder, AND, I will not heat to high temperatures. Let me explain.

The temperature at which most formaldehydes become a vapor is ~60 - 66 Celsius. You know this is correct, as all of you know exactly what (foul sinus-cleaning stench) monomer smells like, and that is @ room temperature. I want to heat the PMMA mix only to these temperature, in an open container, vaporizing and driving out the excess (unreacted) monomer. I use a 3X ULPA carbon filtered fume hood, so my techs do not have to inhale this stuff.
THEN I will load the cylinder, and inject.
This is for the manual mix.
For an automix system, again, at 60 Celsius, why would I have the reactions you describe?

3. Whatever semantics you choose to use. Yes, a nylon BASE from tcs.

Yes, the Mestra is set to a set temperature as per manufacturer requirements, then is used to very slowly cool, no more than 1/2 degree per minute, initially at less than even this. Therefore, while it was purchased for polymerization, the cool-down cycle then accomplishes this and more.
I am though considering trying sodium glycol as solution, instead of water, as physical properties are better.

Is there a SOLID PMMA that can be used in the thermoplastic system?

 

[drm313mac]

While I may or may not be re-inventing the wheel, it is not at the expense of the patient. I guarantee my dentures, unconditionally, w/ free adjustments, free exams.

I am now and always have been a scientist, always seeking to improve systems.

The denture mills use alginate or beeswax, both of which we were taught in school are malpractice for the final impression. The private practices usually use compound and 2 appointments. I use a 4-stage PVS.
Denture mills use Type-II stone, which we were taught is malpractice. Most labs use Type III, some invest-mix. I use Type-IV, invest-mixed.
I am researching a better base plate. I seek something semi-soft yet will not absorb odors, and have yet to find what I seek. Nylons are hydrophilic and difficult to reline, and I know nothing about vinyls.
Denture mills often bypass the wax try-in, where we always do at least 1, and usually 2, sometimes more.
I seek the better physical properties of thermal or thermoplastic.
I seek to eliminate excess monomer if using it at all. Residual formaldehyde is litigation coming, not to mention unhealthy to the patient.
I seek the best in physical properties of the final product. I believe all steps, all errors along the way, build upon one another.

Speaking of unhealthy to the patient, DO NOT tell me I am using the patient as a lab rat, when you believe it is perfectly okay giving them a denture containing excess monomer, a proven human carcinogen. That defines hypocrisy.

Now, I seek to learn from everyone. The techs, the docs, the scientists and engineers, the customers we serve, and I trust in God to teach me. This is why I am here, asking questions. Let's face it; how many docs frequent this board, asking questions?

 

[JohnWilson]

While I may or may not be re-inventing the wheel, it is not at the expense of the patient. I guarantee my dentures, unconditionally, w/ free adjustments, free exams.

I am now and always have been a scientist, always seeking to improve systems.

The denture mills use alginate or beeswax, both of which we were taught in school are malpractice for the final impression. The private practices usually use compound and 2 appointments. I use a 4-stage PVS.
Denture mills use Type-II stone, which we were taught is malpractice. Most labs use Type III, some invest-mix. I use Type-IV, invest-mixed.
I am researching a better base plate. I seek something semi-soft yet will not absorb odors, and have yet to find what I seek. Nylons are hydrophilic and difficult to reline, and I know nothing about vinyls.
Denture mills often bypass the wax try-in, where we always do at least 1, and usually 2, sometimes more.
I seek the better physical properties of thermal or thermoplastic.
I seek to eliminate excess monomer if using it at all. Residual formaldehyde is litigation coming, not to mention unhealthy to the patient.
I seek the best in physical properties of the final product. I believe all steps, all errors along the way, build upon one another.

Speaking of unhealthy to the patient, DO NOT tell me I am using the patient as a lab rat, when you believe it is perfectly okay giving them a denture containing excess monomer, a proven human carcinogen. That defines hypocrisy.

Now, I seek to learn from everyone. The techs, the docs, the scientists and engineers, the customers we serve, and I trust in God to teach me. This is why I am here, asking questions. Let's face it; how many docs frequent this board, asking questions?

Doc are you here to learn from us or dictate what is the best way of doing something?

At my lab I follow the manufactures instructions on how to use a specific product, I do not try and improve the properties of any material that were developed and tested by men far more knowledgeable in material science than I.

You keep referring back to how the "mills" do things, there will always be different business models. The thing that always strikes me as odd is why would a Dr that has gone through school spend as much time as you have researching and learning material science? Is it that you can't find a lab that is able to provide high quality dentures or is that you want to save money by controlling production in house?

As a professional I never ever discourage learning to improve oneself, however I will always suggest that there are very high end labs on this list that would be happy to take this burden off of you.

This can be a symbiotic relationship, I know thats how my long term clients view our relationship.

 

[araucaria]

The process being sought seems too impractical IMO, when staightforward ROI production and simplicity may be a better route. If this was a start-up pizza business a scooter would be a good investment for local deliveries, and not try to build the starship enterprise just to prove some scientific points on speed and final quality at destination. Using a sledgehammer to break a nut. FWIW, I see too many variables that are out of control before the work gets anywhere near the lab. After all the work, the patient will probably leave the denture to dry out at least once and spoil all the efforts. Is it really worth the stress?

 

[drm313mac]

[/COLOR]

Doc are you here to learn from us or dictate what is the best way of doing something?

At my lab I follow the manufactures instructions on how to use a specific product, I do not try and improve the properties of any material that were developed and tested by men far more knowledgeable in material science than I.

You keep referring back to how the "mills" do things, there will always be different business models. The thing that always strikes me as odd is why would a Dr that has gone through school spend as much time as you have researching and learning material science? Is it that you can't find a lab that is able to provide high quality dentures or is that you want to save money by controlling production in house?

As a professional I never ever discourage learning to improve oneself, however I will always suggest that there are very high end labs on this list that would be happy to take this burden off of you.

This can be a symbiotic relationship, I know thats how my long term clients view our relationship.

John,

Learning is a two-way street. Yes, I am learning from you, and yes, I am taking what you say and working it into new things as well. This is the process by which improvements are reached.

Yes, I always read manufacturer's instructions, and I often try other things. My background prior to dental school was engineering physics, mathematical physics, and chemistry, and after dental school was med school and residency. In both I have done research.

In-house: The denture mills taught me one thing, and no, saving money at the expense of quality was not one of these lessons. Having an in-house lab, I have the techs chair-side, always assisting and often performing such as try-ins. One tech per customer eliminates communications errors, as well as guarantees accountability. Most docs are clueless regarding the better materials and methodologies.

By having an in-house lab, yes, I can lower production costs, but not for the reason many seem to believe. By doing so I can compete in price with the mills, yet deliver quality that competes with the private practices, and even betters them in each price point. I have heard many tell me I cannot sell a well-fitting well made denture, with a warranty, free adjustments and free exams, for $300 per plate, competing with the mills in price. Yes, I can, and I can do so only because of the in-house lab. With this lab we can offer different price points, therefore different "models," better at that price point than anyone else.

You see, in dental school we were taught to seek out the more affluent customers. 80% of dentists compete for the top 20% of the population, most of the remaining 20% of remaining private practice dentists go for the 60th% - 80th%, and few are left for the sub-60% brackets. I can serve these people, deliver clinical excellence, at a price they can afford. No, I refuse to only cater to the wealthy.

Your long-term clients: What do they sell your dentures for? $2,800 per plate? That is my price for the complete set, of the best available cutting no corners.

As stated earlier, I believe all steps build one upon the other. I seek to provide the best in each and every step.

 

[araucaria]

extracts from quoted response

Learning is a two-way street. This is the process by which improvements are reached.

Yes, I always read manufacturer's instructions, and I often try other things. My background prior to dental school was engineering physics, mathematical physics, and chemistry, and after dental school was med school and residency. In both I have done research.

In-house: The denture mills taught me one thing, and no, saving money at the expense of quality was not one of these lessons. Having an in-house lab, I have the techs chair-side, always assisting and often performing such as try-ins. One tech per customer eliminates communications errors, as well as guarantees accountability.

By having an in-house lab, yes, I can lower production costs, but not for the reason many seem to believe.

With this lab we can offer different price points, therefore different "models," better at that price point than anyone else.

As stated earlier, I believe all steps build one upon the other. I seek to provide the best in each and every step.

It's great to see such passion and belief in the area of removables, and to witness such dedication to acheiving a predictable and repeatable process. I feel its all a bit excessive, but it's your goal. How do you ensure the whole team is performing to your standards? and what happens if you're unavailable? e.g. vacation, illness, And is this process you're aiming for franchisable? Any thoughts on the impact of digital denture production methods with regard to your plans?

 

[JohnWilson]

So by using a tech chair-side this allows allows you to be more competitive? Maybe I misread your comments, are these techs just there watching you or are they doing the work?

Do you know your true costs to produce a high end denture in house?

As for deviating from the instructions you are not following good GMP's by altering any of these requirements. Being a manufacturer dictates one path when using a specific material. Being an inventor is a totally different animal with its own set of requirements.

As for your question as to what my clients charge, I have never asked, and it is really none of my business. I charge for my product based on what it costs me to produce that item plus my desired profit margin. Their price matters to them not I. As long as I have clients willing to pay me the fee I command there is no reason to think otherwise.

I am not trying to be argumentative, I am just sharing my thoughts from the other side of this glowing screen.

 

[AJEL]

As for lab techs doing the try-in, and then adjustments I was not aware that Ohio had Denturism, In states that have that form of dentistry there is usually additional school required and certification. At 350. per plate to the patient, most quality labs are charging that with Vita or premium teeth to the DDS. I should get back my flexipress is calling for my attention. & as per one other question I don't trust any temperature preset or otherwise I always check to insure the mfg specifications are bring met. GMP

 

[araucaria]

lol, I didnt pay attention to the fee aspect, if thats the price to the pt. then it seems crazily low ($300) and must be difficult to deliver the required standards. High quality professional drs and techs need to be charging a whole lot more than that surely

 

[TomZ]

blah blah blah..blah blah

 

[JohnWilson]

blah blah blah..blah blah

Oh My lord he is alive! Happy New Year Tommy Boy!

 

[TomZ]

Oh My lord he is alive! Happy New Year Tommy Boy!

Yes JW

Alive and thriving...Happy New Year to you also...

Just spending my time in other directions

 

[TECHARTISAN]

Is there a SOLID PMMA that can be used in the thermoplastic system?

Yes, as I said before bre-crystal, acry free, flexite mp are the current offerings of thermoplastic PMMA I am aware of.

1. WHY not? I will not heat IN the cylinder, AND, I will not heat to high temperatures. Let me explain.

If we are losing something in translation I am sorry...be it ivo-capsules or handmixed Diamond D.....heating will initiate/accelerate cure leaving you with a solid mass. This mass should there have been initial residual formaldehyde will likely still contain it within the matrix. This is why injection pellets must be vacuum aged. The plain and simple of it is....while I am sure you have a scientific background, and are probably a decent dentist you are not an FDA licensed medical manufacturer, the expense to become one, and the required annual expenses is hard to justify unless you dont want to be a dentist anymore and want to be a manufacturer. ADA approved materials are only approved for use when used in accordance to the manufacturers instructions....so even if you skirt the FDA your still in troubled waters.

As I said before, if the companies I have mentioned products do not meet your needs....contact them and contract a batch to your specifications.
Do you ever have a client who has been playing dentist at home....cleaning their own teeth with metal pics...etc....Do you not believe that there is a call for relying on properly trained professionals within their specific field?

Yes, the Mestra is set to a set temperature as per manufacturer requirements, then is used to very slowly cool, no more than 1/2 degree per minute, initially at less than even this.

Thanks for confirming....In truth I already knew but thought the comment would benefit others understanding of what you are doing. As I have mentioned in the past the use of thermoplastic acrylic is still pretty uncommon and few technicians are well versed in its nuances.

Institutions reject radical ideas, Radical ideas that survive eventually grow into....Institutions that reject radical ideas. Early adopters of any technology or technique are oft faced with the dichotomy of trying to teach what they are doing, so others understand, while they themselves are still struggling to. There are serious benefits to thermoplastic systems...but unfortunately at this time, there arent a great number of options in providers...yet.

 

[wilkscm]

Nutter

 

[AJEL]

TECHARTISAN Have you worked with the Brea Crystal? bredent GmbH & Co.KG
I have worked with Flexite MP not regularly, I must not have the nack for it the fit is not always what I want and plaster separation isn't really good (maybe it is the 270*c). I could not find a FDA cert for breadent crystal, so I cannot obtain it here to try it. You also must turn up the pressure to max on the flexipres to shoot MP. the FLEXITE F-3 INJECTION MACHINE http://www.flexitecompany.com/Prod.12.htm allows you to hook up to a nitrogen tank or 1/2 air line to get the necessary 146 psi pressure for MP.
The Acri-free looks to be a copy of flexite but has no FDA cert either. http://www.perflexltd.com/index.asp Their denture material even requires the same specs 9.5 bar pressure at 270*c. with a 20 min press. http://www.perflexltd.com/db/content/1q30dt1d.pdf

 

[TECHARTISAN]

I have tried it but not really worked with it. I spent a week in a lab that had switched from using MP to the bre.crystal. AFOAF invited me to check it out when he heard I was thinking about buying a thermal injection system. Im kind of curious now if their using unapproved material...

Anyway....the most significant difference I saw from MP is that the "bead" diameter of brecrystal was smaller.

separator and stone selection seems to make a huge difference not only in this application but in my experience thus far with all thermal injection material. This is only complicated by the higher temperature and pressure requirements. I was pretty impressed with the results though.

 

[drm313mac]

extracts from quoted response



It's great to see such passion and belief in the area of removables, and to witness such dedication to acheiving a predictable and repeatable process. I feel its all a bit excessive, but it's your goal. How do you ensure the whole team is performing to your standards? and what happens if you're unavailable? e.g. vacation, illness, And is this process you're aiming for franchisable? Any thoughts on the impact of digital denture production methods with regard to your plans?

The $300 denture: Is quality possible @ this price? The office manager will try to upsell to a better denture, say @ $525, one where we actually show a profit. If she succeeds, fine, and if $300 is all that customer can afford, okay as well. Why? (1) we are providing a needed service, and (2) the difference between what they pay and the full price of the denture is a tax write-off, offsetting taxation elsewhere.
Generally speaking, we upsell to the next model.

Performing: One tech per customer ensures accountability as well as reduces communications errors. That one tech is with me when I do the impressions, and AJ, state law says I must do the single final impression, but any other can do the preliminary impressions. I checked on this. As the PVS system is easy to learn, I do the facebow, as well as any tracing needed. If say Tech X has a lot more post-delivery adjustments, we know that somewhere there is an issue. Also, I make a point of speaking with each customer.

Vacation and illness, well, hopefully not. Later, I will employ other dentists, partly for this, partly to cover all the surgeries.

Franchise: I intend to expand, but I will retain ownership. You will say that docs will not go with this. I disagree. I pay the doc a guarantee minimum each day, plus so much for each surgery, etc. A doc can easily pull an upper 6-figure income on 4 days per week, assuming a very busy practice.

Digital dentures: We deliver in ~48 - 72 hours, and less. Our quality far surpasses theirs, and our price is lower than they can go for comparable quality. For the foreseeable future, I do not see an impact.

 

[drm313mac]

So by using a tech chair-side this allows allows you to be more competitive? Maybe I misread your comments, are these techs just there watching you or are they doing the work?

Do you know your true costs to produce a high end denture in house?

As for deviating from the instructions you are not following good GMP's by altering any of these requirements. Being a manufacturer dictates one path when using a specific material. Being an inventor is a totally different animal with its own set of requirements.

As for your question as to what my clients charge, I have never asked, and it is really none of my business. I charge for my product based on what it costs me to produce that item plus my desired profit margin. Their price matters to them not I. As long as I have clients willing to pay me the fee I command there is no reason to think otherwise.

I am not trying to be argumentative, I am just sharing my thoughts from the other side of this glowing screen.

True costs are the total of materials plus labor, with miscellaneous. It makes no difference if the denture is low- or high-end. Realistically the costs are the impression material, acrylic used, teeth, and labor, and all else is less by comparison. This is accounted for in my production costs. General office overhead is counted separate from the lab side. 20 - 25 extractions per day cover my office overhead.

GMP: Follow the set paths for the customers, and what we experiment with on the side, working on models, is another issue.

 

[drm313mac]

As for lab techs doing the try-in, and then adjustments I was not aware that Ohio had Denturism, In states that have that form of dentistry there is usually additional school required and certification. At 350. per plate to the patient, most quality labs are charging that with Vita or premium teeth to the DDS. I should get back my flexipress is calling for my attention. & as per one other question I don't trust any temperature preset or otherwise I always check to insure the mfg specifications are bring met. GMP

Ohio allows any, under direct and indirect supervision, to do impressions as long as I do the final, try-in as long as I am present, delivery as long as I am present. The law states what positions can do what procedures.

As for the temperature gauge, is there any you recommend?