Potassium Nitrate by Catherine Mander

Source: Kotoffei. Comics about sensitive teeth. Vector illustration for children dentistry and orthodontics. Cute characters, sour lemon, hot and cold drinks. https://www.shutterstock.com/image-vector/comics-about-sensitive-teeth-vector-illustration-188637992  (accessed February 13, 2020). Reprinted with permission.

I was looking around my house for a chemical that I use in my everyday life and read that my toothpaste had potassium nitrate in it. The first thing that came to my mind was: Why the heck is there an element of fertilizer in my toothpaste? Potassium nitrate is a white crystal that can be dissolved in water and glycerol^{1, 10}. Its molecular formula is KNO₃ and has a molecular weight of 101.103 g/mol¹. This chemical has many different uses it is used in explosives, gunpowder, fireworks, blasting powders, meat preservatives, fertilizers, and toothpaste^{2, 3}.

It can be found naturally in caves and the Atacama Desert in Chile, or produced through the decomposition of feces, urine, and plants in soil and chemical manufacturing^{5, 6}. Potassium chloride is the most common potassium source for the production, then the nitrate source changes based on the manufacture^{6, 11}. 

In toothpaste, it helps to stop the hypersensitivity in your teeth so that you do not feel pain from the nerves⁴. However, when toothpaste for sensitivity are used for a longer then 4 weeks it can have the opposite effect and increase tooth sensitivity⁴. So, the use is cautioned with high concentrations.

It is used as a meat preservative because it keeps the meat red for longer². There is a controversy with where or not the preservatives are causing cancer⁸. It is use in many different types of explosives because it is a strong oxidizer². 

In order for potassium nitrate to be toxic you have to consume a lot of it³. The symptoms of toxicity are dizziness drowsiness and headache⁴. If you eat it then you can experience nausea, vomiting and severe abdominal pain². Based on this information I would say the use of toothpaste such as Pronamel are okay to use, however, you should ask your dentist if it is the best for you to use.

References:

¹National Center for biotechnology Information. Pubchem Database. Potassium Nitrate. https://pubchem.ncbi.nlm.nih.gov/compound/Potassium-nitrate (accessed February 8, 2020).

²Potassium Nitrate. Chemical Compounds [online]; Detroit, MlUXL, 2006. https://go-gale-com.libproxy.mtroyal.ca/ps/i.do?p=GVRL&u=mtroyalc&id=GALE|CX3441700169&v=2.1&it=r&sid=GVRL&asid=9483c65b (accessed February 8, 2020).

³DrugBank. Potassium nitrate. https://www.drugbank.ca/drugs/DB11090 (accessed February 8, 2020).

⁴WebMD. Sodium Fluoride-pot Nitrate Paste. https://www.webmd.com/drugs/2/drug-144318/sodium-fluoride-potassium-nitrate-dental/details (accessed February 8, 2020).

⁵Wallace, K. What Are Some Natural Sources of Potassium Nitrate?. https://sciencing.com/natural-sources-potassium-nitrate-5818529.html (accessed February 8, 2020).

⁶Mosaic. Potassium Nitrate. https://www.cropnutrition.com/resource-library/potassium-nitrate (accessed February 8, 2020).

⁷Poulsen S, Errboe M, Hovgaard O, Worthington HW. No strong evidence supports the efficacy of potassium nitrate toothpaste for dentine hypersensitivity. Evidence-Based Dentistry 2001, 2. https://www.nature.com/articles/6400085.pdf?origin=ppub (accessed February 8, 2020).

⁸Wilson, B. Yes, bacon really is killing us. https://www.theguardian.com/news/2018/mar/01/bacon-cancer-processed-meats-nitrates-nitrites-sausages (accessed February 8,2020).

⁹Merriam-Webster. Hypersensitive. Merriam-Webster.com Dictionary [online]; https://www.merriam-webster.com/dictionary/hypersensitive (accessed February 10, 2020).

¹⁰Potassium nitrate. https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/p/Potassium_nitrate.htm (accessed February 8, 2020).

¹¹Potassium nitrate Association, Production process. http://www.kno3.org/about-potassium-nitrate/production-processes (accessed February 10, 2020).