Should you avoid using metal with bentonite clay? - truthpaste
June 17, 2024

Should you avoid using metal with bentonite clay?

By Marisa Battrick

At Truthpaste, we prioritise both the effectiveness and safety of our products. One common concern we encounter is whether metal utensils can interfere with the properties of bentonite clay in our toothpaste. Let's dive into the science and clear up any misconceptions.

 

What is bentonite?

Bentonite clay, a key ingredient in our toothpaste, is renowned for its high adsorption capacity. This unique property stems from its layered structure and net negative charge, which allows it to attract and bind positively charged ions and impurities.

It is used in cosmetics or therapeuticals to help absorb toxins, heavy metals and other impurities.

Used in oral care, it can help clean and polish teeth. Due to its unique properties, it has a lower abrasivity score but higher cleaning efficiency. 

 

Does using metal de-activate bentonite clay?

First, what does ‘activated’ mean?

In the context of charcoal or bentonite, the term ‘activated’ refers to a process that enhances the material’s ability to absorb substances by increasing its surface area. 

The bentonite in Truthpaste is activated by using a Jet Mill which micronizes using air to reduce the particle size of the material  to less than 30 microns. 

 

What does ‘deactivating’ mean in terms of bentonite?

If activating bentonite refers to increasing its ability to absorb substances, then ‘deactivating’ bentonite would mean losing its ability to absorb substances.

 

How does bentonite clay become ‘deactivated’?

Bentonite's adsorption properties depend primarily on its physical structure and chemical composition. If bentonite was to come into contact with certain contaminants, its absorption efficiency could be affected.

 

Why use Bentonite in toothpaste?

As well as being rich in minerals and its absorption properties, bentonite can be used as an abrasive agent, replacing more common ingredients such as hydrated silica. Bentonites unique properties mean it is effective at cleaning and polishing teeth without being too abrasive. 

A study conducted in 2011 evaluated 26 different toothpastes to assess their abrasion, polishing, and stain removal properties based on various mineral components. The ingredients examined included hydrated silica, calcium carbonate, sodium bicarbonate, dicalcium phosphate, pentasodium triphosphate, kaolin clay, and bentonite clay.

The research focused on measuring the Relative Dentin Abrasivity (RDA) and the Pellicle Cleaning Ratio (PCR), which indicate how abrasive a toothpaste is and how effectively it cleans or whitens teeth, respectively.

Each toothpaste was assigned a Cleaning Efficiency Index (CEI). Toothpastes that exhibited high whitening capability with low abrasivity received a high CEI score, while those with high abrasivity but low cleaning efficiency scored lower.

Generally, increased abrasivity corresponded with better cleaning efficiency, with the exception of toothpastes containing mineral clays like bentonite or kaolin.

Toothpastes formulated with bentonite demonstrated higher cleaning efficiency with lower abrasivity compared to those containing hydrated silica and conventional abrasive ingredients.

 

Can you use stainless steel with bentonite?

Stainless steel does not chemically interact with bentonite in a way that would deactivate it. Stainless steel is a common material used in various industrial applications due to its resistance to corrosion and contamination.

Stainless steel is generally resistant to corrosion and does not easily leach substances that would contaminate bentonite. However, if the stainless steel surface is contaminated with oils, greases, or other substances, these contaminants could transfer to the bentonite and potentially affect its absorption ability. The effectiveness of Truthpaste does not rely on bentonites ability to absorb. 

  

Does Using Metal ‘Deactivate’ Bentonite?

If the metal utensil or container is corroded or contains reactive metals, there might be a risk of introducing metal ions into the clay. However, stainless steel and most common metals used in kitchen utensils are non-reactive and unlikely to leach significant amounts of ions that could affect the clay’s properties. 

 

What metals should you avoid with bentonite?

Specific metals that should be avoided with bentonite include iron, copper, and aluminum, as they are reactive and can potentially affect the clay's properties.

The aluminium used our packaging is coated with a food safe resin to prevent contamination.

 

Is bentonite toothpaste safe to use with metal amalgam fillings?

Amalgam fillings are composed of a mixture of metals, including silver, tin, copper, and mercury. These metals are bound together in a stable matrix that is designed to withstand the oral environment. 

The metals in amalgam fillings are stable and designed to resist corrosion and degradation in the oral environment. Bentonite clay, primarily composed of montmorillonite, does not contain reactive components that would corrode or degrade these metals.

Studies on the chemical stability of dental materials indicate that the metals used in amalgam fillings do not easily interact with other substances in the mouth, including bentonite clay

Bentonite clay’s primary properties, such as its adsorption capacity and negative charge, are stable and not significantly affected by contact with metals in amalgam fillings. The brief contact during brushing is unlikely to alter these properties.

Using bentonite clay toothpaste with metal amalgam fillings is safe. The metals used in amalgam fillings are designed to be stable and non-reactive in the oral environment. Bentonite clay, with its stable adsorption properties, does not interact negatively with these metals. Therefore, you can use bentonite clay toothpaste without worrying about compromising amalgam fillings or the effectiveness of the toothpaste.

 

Is bentonite toothpaste safe to use with metal braces?

 

The metals used in dental braces, such as stainless steel, nickel-titanium alloys, and other specialized dental metals, are chosen for their biocompatibility and resistance to corrosion. These metals are designed to be non-reactive in the oral environment.

Bentonite clay’s primary properties, including its adsorption capacity and negative charge, are stable and not significantly affected by contact with metal. The brief interaction between the clay and metal braces during brushing is unlikely to alter these properties.

Studies on the chemical stability of dental materials indicate that the metals used in braces do not easily interact with other substances in the mouth. Bentonite clay, primarily composed of montmorillonite, does not contain reactive components that would corrode or degrade these metals. 

The adsorption properties of bentonite clay are effective in binding impurities and toxins, but these properties are not compromised by contact with non-reactive metals. The metal braces do not release ions or compounds in amounts that would interact negatively with the clay.

Using bentonite clay toothpaste with metal dental braces is safe. The non-reactive nature of the metals used in braces, combined with the stability of bentonite clay’s properties, ensures that there are no adverse interactions. You can use bentonite clay toothpaste without worrying about compromising dental braces or the effectiveness of the toothpaste.

 

 

 

 

Can metal interfere with bentonite clays negative charge?

Bentonite clay is primarily composed of montmorillonite, which has a layered structure with a net negative charge. This negative charge allows bentonite to attract and bind positively charged ions (cations) and molecules.

The effectiveness of bentonite clay in adsorbing toxins, heavy metals, and other impurities is due to its high surface area and negative charge. The negative charge is a result of isomorphous substitution within the clay structure, which is a stable property not easily altered by brief contact with metals.

Short-term contact with metal utensils (like stirring with a metal spoon or storing in a metal container) is unlikely to alter the fundamental charge properties of bentonite clay. The negative charge on bentonite is due to its crystalline structure and is stable under normal conditions (ie without being subjected to intense heat or pressure).

 

Avoiding contamination risk

In summary, the negative charge of bentonite clay, which underpins its adsorptive properties, is derived from its stable crystalline structure and is not easily altered by brief contact with metal utensils.

Therefore, using stainless steel or other common kitchen metals with bentonite clay is unlikely to deactivate or significantly affect its effectiveness.

However, it is important to avoid contamination through corroded metals, or utensils or storage containers (metal or non-metal) that are contaminated with oils, grease, or other contaminants. It is important to note that this is the case for any product - bentonite based or not!  It's also worth noting that the effectiveness of bentonite based toothpaste is not solely dependant on bentonites absorption qualities. 

Using a clean stainless steel spatula to scoop our bentonite toothpaste can reduce the risk of contaminating the product without loosing any of the benefits of bentonite. 

 

Resources

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Abollino, O., Aceto, M., Malandrino, M., Sarzanini, C., & Mentasti, E. (2003). Adsorption of heavy metals on Na-montmorillonite. Effect of pH and organic substances. Water Research, 37(7), 1619-1627. DOI: 10.1016/S0043-1354(02)00524-9

Adamson, A. W., & Gast, A. P. (1997). Physical Chemistry of Surfaces. Wiley-Interscience.

Churchman, G. J., & Lowe, D. J. (2012). Alteration, Formation, and Occurrence of Minerals in Soils. In Soil Mineralogy with Environmental Applications (pp. 1-72). Soil Science Society of America.

Callister, W. D. (2007). Materials Science and Engineering: An Introduction. John Wiley & Sons.

ASTM International. (2020). Standard Specification for Stainless Steel Bars and Shapes. ASTM A276/A276M-20.

FDA. (2020). Code of Federal Regulations Title 21, Part 175.300: Resinous and Polymeric Coatings. U.S. Food and Drug Administration.

Soroka, W. (2002). Fundamentals of Packaging Technology. Institute of Packaging Professionals

Sedriks, A. J. (1996). Corrosion of Stainless Steels. John Wiley & Sons.

Ohta, K., & Kikuchi, Y. (1999). Microbial adhesion to stainless steel surfaces. Journal of Industrial Microbiology & Biotechnology, 22(5), 269-273. DOI: 10.1038/sj.jim.2900621 

Putt, M. et. al. (2011) Abrasion, polishing, and stain removal characteristics of various dentifrices in vitro The Journal of Clinical Dentistry

Ferracane, J. L. (2001). Materials in Dentistry: Principles and Applications. Lippincott Williams & Wilkins.

Anusavice, K. J., Shen, C., & Rawls, H. R. (2012). Phillips' Science of Dental Materials. Elsevier Health Sciences

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