Is polycaprolactone (moldable plastic) toxic?

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Polycaprolactone is used as moldable plastic and you can mold in into thousands of shapes. Is it toxic like Acrylic? Does Polycaprolactone have polymerization chain as described below for acrylic?

6694_Image.jpg


"Acrylics are not completely safe materials because their polymerization chain reaction is never absolute. Potential causes of their harmfulness are unpolymerized components and by-products of the polymerization reaction.. The individual components of acrylic materials have the ability of leaching dentures and diffusing into saliva, thus influencing oral tissues and the organism in general.. The components which are released from the acrylic resin material by electrolysis or hydrolysis processes are absorbed into the oral mucosa, gastrointestinal tract, skin, and respiratory system. The absorption mechanism depends on the nature and chemical properties of the released elements. Adverse effects of acrylate components on tissues are less often caused by their toxicity but, more frequently, by their immunological functioning."
 

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  • #2
jrmichler
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Start with the safety data sheet, which all chemicals are supposed to have. Search terms safety data sheet polycaprolactone found several safety data sheets for polycaprolactone.
 
  • #3
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"Acrylics are not completely safe materials because their polymerization chain reaction is never absolute. Potential causes of their harmfulness are unpolymerized components and by-products of the polymerization reaction.. The individual components of acrylic materials have the ability of leaching dentures and diffusing into saliva, thus influencing oral tissues and the organism in general.. The components which are released from the acrylic resin material by electrolysis or hydrolysis processes are absorbed into the oral mucosa, gastrointestinal tract, skin, and respiratory system. The absorption mechanism depends on the nature and chemical properties of the released elements. Adverse effects of acrylate components on tissues are less often caused by their toxicity but, more frequently, by their immunological functioning."
I googled "polymerization chain reaction". All the searches produced Polymerase Chain Reaction". What does "polymerization chain reaction" mean above?
 
  • #4
Baluncore
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What does "polymerization chain reaction" mean above?
The reaction that makes long chains molecules from many smaller parts.

Polymers are assembled as structures from isomers, usually in the presence of a catalyst.
Some catalyst, isomers and impurities will remain embedded in the physical structure. The polymer chain may be stable over a range of conditions, but the catalyst, isomers and impurities may be mobile.
 
  • #5
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The reaction that makes long chains molecules from many smaller parts.

Polymers are assembled as structures from isomers, usually in the presence of a catalyst.
Some catalyst, isomers and impurities will remain embedded in the physical structure. The polymer chain may be stable over a range of conditions, but the catalyst, isomers and impurities may be mobile.
Polycaprolactone requires reaction that makes long chains molecules from many smaller parts. Is it not?
 
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  • #8
Baluncore
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I read acrylic could be toxic but not polycaprolactone.
Was that written by the marketing department? Can you give a reference.

Everything is toxic, including good food.

You must study the many different ways to make the polymer. Ring monomers can be opened and linked together to form chains. There are many possible catalysts, anything from water to metal ions might be used. https://en.wikipedia.org/wiki/Ring-opening_polymerization

The particular polymerisation process employed, and the purity of the ingredients will decide the issue. There is no hard and fast general rule. You must identify the exact process.
 
  • #9
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Was that written by the marketing department? Can you give a reference.

Everything is toxic, including good food.

You must study the many different ways to make the polymer. Ring monomers can be opened and linked together to form chains. There are many possible catalysts, anything from water to metal ions might be used. https://en.wikipedia.org/wiki/Ring-opening_polymerization

The particular polymerisation process employed, and the purity of the ingredients will decide the issue. There is no hard and fast general rule. You must identify the exact process.
From a medical article "Adverse reactions to denture resin material" see https://www.google.com/url?sa=t&sou...FjAAegQIBxAB&usg=AOvVaw2S17bVTrwDnkj_DgvkkvWZ
 
  • #10
Baluncore
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European Review for Medical and Pharmacological Sciences. 2017; 21: 5298-5305
Adverse reactions to denture resin materials.
That article discusses some possible problems with acrylic materials, but where is the mention of polycaprolactone.
 
  • #11
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European Review for Medical and Pharmacological Sciences. 2017; 21: 5298-5305
Adverse reactions to denture resin materials.
That article discusses some possible problems with acrylic materials, but where is the mention of polycaprolactone.
Thats the reason i wrote this thread, seeking info whether polycaprolactone is safer than acrylic and no adverse reaction in case its used in the tissue?
 
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  • #12
Baluncore
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I read acrylic could be toxic but not polycaprolactone .
Ah, there are two interpretations to that sentence.
1. I read acrylic could be toxic, but I did not read anything about polycaprolactone toxicity.
2. I read that acrylic could be toxic, and I read that polycaprolactone could not be toxic.


On the subject of the quoted paper. It is the sort of paper that is produced after an investigation that did not find anything. The introduction says;

1. “The long-term use of acrylic materials in dentistry is the proof of their satisfactory biological, physical and mechanical properties”. So there is no real problem.

2. “However, in time it has been shown that the acrylic polymers announced in the first half of the twentieth century are not the ideal building material”. That is 1900 to 1950, between 70 and 120 years ago. They are not ideal, but there is still no major problem.

3. “Although not perfect, they considerably meet the requirements of everyday dental practice due to relatively good biocompatibility, their chemical inertness, fair mechanical properties, dimensional stability, the possibility of coloring and transparency, simple processing, the possibility of repairing as well as their low price.” So there is still no problem.

The paper then plays devil's advocate without any real finding, before the conclusion where;

1. “Despite the fact that acrylics are not ideal materials and that their integration in the orofacial system cannot be without any consequences, they are widely used and have an enviable list of possible indications”.
Which says: if you need dentures, acrylic is probably still a reasonable choice.

Publish or perish. All it has done is cast fear, uncertainty and doubt on the safety of acrylic dentures, without actually finding anything substantive to hang the paper on.
 
  • #13
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Here are more evidences of the effects of acrylic on tissues:

https://www.researchgate.net/public...Contact_Dermatitis_from_Hearing_Aid_Materials

"A 65-year-old woman presented with dermatitis of the ear canal. The dermatitis had developed after she started wearing hearing aids that fit into the ear canals. Patch-test results were positive for (1) several acrylics, including polyethylene glycol dimethacrylate and 2-hydroxyethyl methacrylate, which were present in the hearing aid shell; (2) the hearing aid shell materials; and (3) the finish coat. The dermatitis resolved after she discontinued wearing the hearing aid, and a device with a silicone earpiece to be worn behind the ear was recommended as an alternative."

http://www.jptrs.org/journal/view.html?doi=10.14474/ptrs.2014.3.2.119#T1

"
Objective
The use of chemicals for building prosthetic sockets present the possibility of being hazardous and unsafe due to off-gassing. The purpose of the present study was to investigate if freshly made materials used in prosthetic sockets causes off-gassing that would penetrate the skin and cause damage to the kidneys or blood.

Design
Cross-sectional study.

Methods
In this research, the off-gassing effects during the initial curing process of styrene monomer, vinyl ester resin, epoxy methacrylate resin, benzene-1, 3-dimethaneamine, trimethylhexanedlamine, and paratertiarybutylphenol were analyzed. Acid detection strips were placed inside newly fabricated mock-prosthetic sockets and left overnight in a closed environment to find out if acid was present in the invisible fumes. The plastic was worn by 9 subjects and urinalysis was made after 48 hours to test for any kidney or blood toxicity of the resins.

Results
After wearing the plastic cuff for 48 hours, the ratio of protein to creatinine in the urine was raised to an abnormal level in five out of nine subjects. Four out of the nine subjects showed normal protein to creatinine ratios after wearing the device. The results showed that damage to the kidney occurred from wearing the resins after curing in half of the subjects.

Conclusions
It is very important to conduct patient intakes which includes the assessment of renal function. "Off-gassing in vented chambers may be needed to protect both prosthetists and patients.

Keywords : Chemicals in acrylic resin, Off-gassing, Prosthetics
 
  • #14
Baluncore
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@Secan
It seems you are cherry picking the literature for anecdotes that support your prejudice.

You must weigh the problems against the benefits. Without that balance you will try to ban acrylic dentures because one patient might be temporarily irritated, while 10000 could benefit.

What are you trying to do here? Are you trying to prevent people wearing dentures made from acrylic? Do you want to prosecute a chemical manufacturer for producing a widely used product? Or are you just anti-plastic because they are "man-made" products.
 
  • #15
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@Secan
It seems you are cherry picking the literature for anecdotes that support your prejudice.

You must weigh the problems against the benefits. Without that balance you will try to ban acrylic dentures because one patient might be temporarily irritated, while 10000 could benefit.

What are you trying to do here? Are you trying to prevent people wearing dentures made from acrylic? Do you want to prosecute a chemical manufacturer for producing a widely used product? Or are you just anti-plastic because they are "man-made" products.
None of the above. I just wonder what are these ear molds materials made of and whether it can harm babies. These products are mostly made in USA and most other countries dont have them.

The best some can make are acrylic ear molds or one from molding plastic.

20200802_102113.jpg
 
  • #16
Baluncore
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I just wonder what are these ear molds materials made of and whether it can harm babies.
Then you should contact the manufacturer to identify the polymer used.
 
  • #17
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Then you should contact the manufacturer to identify the polymer used.

US doctors made them custom. Unfortunately no manufacturers for them or i could have asked already. Doctors would only talk to you at actual visits.
 
  • #18
Baluncore
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Get a copy of the MSDS for polycaprolactone.
https://www.polysciences.com/skin/frontend/default/polysciences/pdf/19561.pdf
Polycaprolactone is non-hazardous, non toxic.
Precautions. Wear gloves and eye protection.
It might cause irritation to eyes. Keep it away from eyes. ( Follow section 4 ).
Do not eat it.
Don't use it as fuel for a fire. (Smoke is an unspecified hazard).
If you spill it, sweep it up, and dispose of it.
It will absorb water. (Like all polymers, I expect it will swell slightly if it gets wet).
It is supplied as flakes that melt at 140°F. It is stable.

US doctors made them custom. Unfortunately no manufacturers for them or i could have asked already. Doctors would only talk to you at actual visits.
The doctor takes the risk, and has professional practice insurance. Polycaprolactone for medical applications will be high purity, without significant contaminants.

If you are unlucky enough to develop a sensitivity, follow MSDS section 4, avoid further contact, go back to the doctor.
 
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  • #19
139
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Get a copy of the MSDS for polycaprolactone.
https://www.polysciences.com/skin/frontend/default/polysciences/pdf/19561.pdf
Polycaprolactone is non-hazardous, non toxic.
Precautions. Wear gloves and eye protection.
It might cause irritation to eyes. Keep it away from eyes. ( Follow section 4 ).
Do not eat it.
Don't use it as fuel for a fire. (Smoke is an unspecified hazard).
If you spill it, sweep it up, and dispose of it.
It will absorb water. (Like all polymers, I expect it will swell slightly if it gets wet).
It is supplied as flakes that melt at 140°F. It is stable.


The doctor takes the risk, and has professional practice insurance. Polycaprolactone for medical applications will be high purity, without significant contaminants.

If you are unlucky enough to develop a sensitivity, follow MSDS section 4, avoid further contact, go back to the doctor.
Outside the US. They dont make ear molds for 0 to 2 month old infant. I let a hearing aid fabricator create an ear mold for lop ears (where the helix is folded at the top). They havent done it before. Not only is the shape wrong but the spring or connection is wrongly placed. It is acrylic. They only use acrylic or silicone for ears.

20200815_151225.jpg


This is the original made by doctors in US.

Screenshot_20200815-224603_YouTube.jpg


Anyone know where to buy similar spring?

I tried to make one using polycaprolactone but its difficult to create exact shape.

20200819_104549.jpg
 
  • #20
Baluncore
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Modify a spring from eBay, search for; 'fake-piercing spring'
Making the ear moulds is a job for a 3D printer.
Measure the dimensions with curved radius gauges cut from sheet material.
 
  • #21
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By the way. I didnt continue with this project. The ENT doc told me pressing the ears wrongly can darken a part. And if you will see pictures of cauliflower ears where the ears just melted. You will get the idea. This is because the cartilege of ears got its blood supply from the ear skin so if you cause a hematoma or necrotic skin by pressing wrong part or tension it could cut of supply to the cartilage so yours ear shape can be gone. So dont try it at home. Let the professionals handle ear molds. If one is grown up with folded helix in the ears. Minor surgery can correct it. Pls share your experience (those with or know people with folded helix in ears).
 
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