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Mica in Toothpaste: Benefits & Safety

The benefits of adding mica as an ingredient in toothpaste is as a whitening abrasive and also as a colorant. Therefore, it plays a role in cleaning and whitening the teeth as well as making the paste look aesthetically pleasing.


Mica in toothpaste overview:


 

What is Mica?

Mica or rather "Micas" refer to a group of 37 different phyllosilicate minerals which can be naturally found. Therefore when you see mica in toothpaste, it doesn't necessarily tell you specifically what it is.


Muscovite Rose with Apatite
Muscovite Rose with Apatite. Credit:Aldea Velha Mine, Conselherio, Pena, Minas Gerais, Brazil. University of Waterloo Earth Sciences Museum Collection.

Examples of mica:

  • Igneous rocks

  • Muscovites - granites, granitic pegmatites, aplites

  • Phlogopites - peridotites, kimberlites

  • Biotites - gabbros, norites, diorites, syenites, granites, pegmatites

  • Lepidolite and Zinnwaldite - pegmatites and high temperature veins.

  • Metamorphic rocks

  • Muscovite, paragonite, and biotite: phyllites, schists, and gneisses.

  • Phlogopite: metamorphosed limestones and dolomites.

  • Sedimentary rocks

  • Muscovite and paragonite: detrital and authigenic sediments.

  • Glauconite - greensands


A defining characteristic for this type of minerals is the potential for perfect basal cleavage where the individual mica crystals can be split into extremely thin elastic plates.


The most well known uses of mica to the general public would be as a toothpaste ingredient and also in cosmetic products like eyeshadow.


  • Alloys (lithium from Lepidolite)

  • Aluminum production

  • Artificial snow

  • Asphalt roofing felts and shingles (protective coating and weather proofing)

  • Batteries (lithium from lepidolite)Other uses

  • Beauty products Casting (mica strainer used in producing bronze, brass and aluminum castings)

  • Ceiling tiles

  • Christmas ornaments (as a flocking materials and to provide glittering effects)

  • Commutators

  • Concrete block fillers, refractory bricks, gypsum board (reinforcing structures, fire resistance, sound absorption, corrosion protection)

  • Condenser Plates (mica is covered with silver to make capacitors.)

  • Used to produce the energy to make the camera flash work

  • Explosives (as an absorbant)

  • Foundry works, enamels, mastics and adhesives (improves physical properties, anti-sag, reduces cracking)

  • Glass (lithium from lepidolite)

  • Guided missiles

  • Heating elements (electrical insulation. The wire is wrapped around the mica in toasters, irons, kettles and hair driers)

  • Insulators (wires, toasters, irons, etc.)

  • Lasers (lithium from lepidolite)

  • Liquid level indicators (mica is unaffected by high temperature and pressure. It is used for checking boiler for liquid level and pressure of steam)

  • Lubricants Medication - psychiatric disorders (lithium from lepidolite)

  • Microwave windows

  • Oil well drilling (drilling mud additive to overcome loss of circulation)

  • Ornamental stone

  • Paint, textured (improves physical properties and durability, adhesion and water proofing)

  • Pearlescent pigments (provides lustre in paints, lipstick and other materials)

  • Plaster (improves acoustical properties)

  • Plastics (improves thermal and dielectric properties, impact strength and heat resistance)

  • Rocket propellants (lithium from lepidolite)

  • Roofing shingles

  • Rubber (prevents adhesion of rubber compound to the mould during vulcanisation)

  • Soldering irons

  • Spark plugs

  • Telephones

  • Television tubes (mica spacers to hold tube elements in position and insulated from one another and lithium from lepidolite)

  • Transistors (heat and electric insulator)

  • Wall-paper

  • Welding electrodes, cables and wires (protective coatings, and improves dielectric properties, electrical and mechanical strength)

  • Welding rods (lithium from lepidolite)

  • Well-drilling muds

  • Windows (kerosene lamps, and furnaces)


 

What mica does in toothpaste

The two main functions of mica in toothpaste is as a mild whitening abrasive and also as a shimmering colorant.


Whitening abrasive

Mica is a mineral and will be mildly abrasive which makes it a good whitening abrasive to remove extrinsic stains from the surfaces of teeth.


The way it works is similar to hydrated silica in that its mildly gritty physical characteristic allows it to mechanically abrade stains. The mild abrasiveness permits it to scrub away stains on the exterior tooth surface.


In other words, you can think of it as micro-polishing the enamel surface to remove tooth stains. That is essentially how most whitening toothpastes clean your teeth and make them whiter.


Shimmering colorant

A secondary function of adding mica to toothpaste is for its shimmering/glittering/sparkling optical properties. The addition of it will make the toothpaste sparkle and glitter thus serving as an aesthetic modulator.


In other words, this function is purely for aesthetic purposes because it makes the paste look pretty. In case you don't believe us, we've a comparison video of what a mica toothpaste looks like vs non-mica toothpastes.



Below are still photos showing you the comparison of a mica toothpastes vs 2 toothpastes without it.


Mica toothpaste vs non-mica toothpastes by pronamel
Mica toothpaste vs non-mica toothpastes by pronamel

It may be a little hard to see so we zoomed in and magnified the next image.


Toothpaste color for mica vs non-mica
Magnified view

Once again, we magnified it even more! Here you can see little specks of sparkles and shimmering substances embedded within the mica-based dentifrice.


Magnified view of mica toothpaste vs 2 non-mica toothpastes
Close up view of sparkling mica paste

Is that convincing enough for you?


The lighting may make it a little hard to distinguish in the photos but we promise you that as soon as we dispensed the toothpaste, we immediately noticed that it was different from the usual opaque white colored pastes.


 

Side effects

According to the NJ Department of Health, there may be potential hazardous side effects from coming into contact, inhalation, or ingestion of mica.


Adverse effects:

  • Fibrosis (lung scarring)

  • Lung cancer

  • Emphysema

  • Coughing

  • Shortness of breath

  • Other respiratory problems.


Most of these side effects are due to inhalation of the mineral over a long period of time. There are currently no acute (short term) effects from immediate exposure but long term chronic exposure may result in these health effects.


 

Safety

Mica is approved by the FDA to be used as a color additive to many foods, drugs, cosmetics, and medical devices. Yes, that includes dentifrices like toothpastes. For toothpaste specific approval, you can find it at the code of federal regulations 73.1496 Mica.


However, it would behoove you to know that previously it was labeled as an air contaminant by OSHA/NIOSH with specific workplace limits.

  • Limit - 20 million parts per cubic foot over an 8-hour workday.


Although the most recent update on the CDC website states that the current limits are NOT in effect due to the US Circuit Court of Appeals.


OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. This rule was remanded by the U.S. Circuit Court of Appeals and the limits are not currently in force.

Now isn't that fascinating?


Is it safe to use in toothpaste?

In our opinion, mica is safe for use in toothpaste because none of it is being swallowed. The directions/instructions for all toothpastes explicitly state that you shouldn't swallow it because you should be spitting it back out.


Overall, there should be minimal to no ingestion of this toothpaste ingredient. We may be more concerned if there was mica in food but for dentifrices, it shouldn't present as an issue.


 

Abrasiveness

Mica is considered a soft mineral with a 2.5-4 on Mohs scale of hardness and that means it is safe to use on enamel. The reason is because enamel has a 5 on Mohs hardness scale so it won't get scratched by it since it is harder than it.


Mineral

Mohs Hardness Scale

Mica

2.5-4

Hydroxyapatite (Enamel)

5


In summary, enamel is harder relative to mica so it is unlikely for it to be harmed. Therefore, I wouldn't even worry about any potential enamel damage while brushing with this ingredient.

Kommentare


David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

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Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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