Hot dog buns come in packages of six, while hot dogs themselves come in packages of eight. We have already addressed this problem as they pertain to hot dogs. Despite that exceedingly well-written letter on such a pressing issue, Representative Scott Peters only replied with a cookie-cutter reply about how much he cares about local issues and loves hearing from his constituents. A year later, in a new decade, the same matter continues to plague our great nation.
We are not here, however, to lament the slow workings of the United States Congress nor its inability to tackle the truly important matters; we are here to ask another question: has Big Oral Hygiene been taking pointers from Oscar Mayer himself?
The toothbrush and toothpaste go hand in hand, so it should only make sense that one would need to buy a new tube of toothpaste every time their toothbrush needs to be replaced. Through rigorous research, experimentation, and investigative journalism we must answer the question: is there too much or too little toothpaste in a standard tube?
Our main question necessitates asking another, as is the nature of questions. We need to know how much toothpaste one needs to use with each brushing: a seemingly innocuous enough question that will lead us into rabbit hole after rabbit hole. Let’s start simply by looking at the back of a tube of toothpaste:
– Adults and children 2 years of age and older: Brush teeth thoroughly, preferably after each meal or at least twice a day, or as directed by dentist or physician.
– Children 2 to 6 years: Use only a pea sized amount and supervise the child’s brushing and rinsing (to minimize swallowing).
– Children under 2 years: Ask a dentist or physician.
Directions on Colgate Cavity Protection Toothpaste with Fluoride 6 o.z
– adults and children 2 yrs. & older: brush teeth thoroughly after meals or at least twice a day or use as directed by a dentist
– do not swallow
– to minimize swallowing, use a pea-sized amount in children under 6
– supervise children’s brushing until good habits are established
– children under 2 yrs.: ask a dentist
Directions on Crest 3D White Toothpaste Radiant Mint 4.1 o.z.
The directions on both Colgate and Crest toothpaste are identical, except for the fact that Crest has less respect for capitalization and physicians. Neither of these two figureheads of Big Oral Hygiene make any assertions as to how much toothpaste adults should be using, only that children should be using a “pea-sized amount” of it. Our question remains unanswered.
There exists a corner of the internet that peddles the conspiracy that toothpaste manufacturers show images of toothpaste covering the entire head of the toothbrush in order to deceive consumers into believing that they need more toothpaste than they actually do. They assert that adults only need to use a “pea sized” amount of toothpaste, the amount that Big Oral Hygiene claims is sufficient for children. Organizations such as HowStuffWorks and Harris Dental claim this, but neither provide any actual data or evidence to back it up.
Most adults tend to think that it is necessary to cover the entire brushing surface of a toothbrush because of the way toothpaste is advertised on television. Liberal use of toothpaste is far too much; it is only necessary for adults to use an estimated pea sized dab of toothpaste to properly clean their teeth.
Harris Dental (2013)

We cannot accept this claim at face value; addressing an issue as important as the amount of toothpaste in each tube requires the most watertight of facts and evidence. However, we must not be so hasty to dismiss this claim either, especially with its large backing.
What does the United States Government, protector of America’s teeth and gums, have to say about the amount that we should use? Toothpaste, including its labelling, is regulated by the Food and Drug Administration under Title 21 of the Code of Federal Regulations, Volume 5, Part 355. Unfortunately, while these regulations provide concrete direction on how to label each tube of toothpaste, but provide no input on the amount of toothpaste that should be used with each brushing. They only lay out the minimum information required to be provided under “directions”:
Adults and children 2 years of age and older: Brush teeth thoroughly, preferably after each meal or at least twice a day, or as directed by a dentist or doctor. Instruct children under 6 years of age in good brushing and rinsing habits (to minimize swallowing). Supervise children as necessary until capable of using without supervision. Children under 2 years of age: Consult a dentist or doctor.
21 C.F.R. §355.50(d)(1) (2020).
With no guidelines provided by the FDA, the toothpaste scientists at both Crest and Colgate seem to have decided that, of all available vegetables, a pea is the best reference for the amount of toothpaste that necessary for brushing in children.
From here we need to make one of two assumptions: (1) the conspiracy theorists are right and adults only need a pea-sized amount of toothpaste or that (2) adults, with more and larger teeth than children, need more more toothpaste.
In exploring either of these assumptions, we need to define a pea-sized amount of toothpaste. To that end we have procured a reference pea. It has all the properties of a quintessential pea; it is green, small, and somewhat round. The reference pea is sourced from a half-used 64 ounce bag of Springfield Mixed Vegetables Fancy in the freezer. It was the first pea that was easily dislodged from the frozen mass of green beans, carrots, corn, and other peas. The pea was consumed after it had outlived its usefulness as a reference; it tasted fine.

From here, it is simple enough to squeeze out what qualitatively appears to be a pea-sized amount of toothpaste and weigh it. Repeated a few times, we find that a pea-sized amount of toothpaste is approximately 0.4 grams. Our reference pea is only 0.3 grams, but this is an unimportant fact.

To explore one extreme of our situation, we can assume that the average person brushes their teeth only twice daily and will use only a pea-sized amount of toothpaste, as the conspiracy theorists allege. Colgate recommends replacing a toothbrush every three to four months. At 0.4 grams a brush, 2 brushes daily for 90 days, one would need 72 grams or 2.5 ounces of toothpaste per toothbrush; that’s more than enough, as most toothpastes come in tubes of 5 to 6 ounces.
Exploring the other side of this, we will take Big Oral Hygiene’s word over the conspiracy theorists’ and assume that an adult needs more toothpaste than a child (some actually claim that we don’t need toothpaste at all, but that’s another rabbit hole that would defeat the entire premise of this work, so we must ignore it). Here we encounter our biggest challenge yet: how much more toothpaste does an adult need compared to a child?
No one knows. Or, at least, if they do, they’re keeping it a secret. We must again rise to our true calling to expose uncomfortable truths and hold power to account, impartially and unflinchingly, and figure out how much more toothpaste an adult might need compared to a child.
The purpose of toothpaste is to deliver fluoride to the enamel. Adults have more enamel, with their larger and more numerous teeth, will need more fluoride and more toothpaste. Dentistry, like every other industry, has its secrets and none is perhaps better kept than the mass of enamel in baby teeth compared to adult teeth.
Exhaustive research, poring over decades-old dentistry textbooks and paper after paper on tooth composition, reveals that either this is such common knowledge that dentists that it’s not written down anywhere or its knowledge that is currently unknown to science (probably not the second one). These must be dentistry secrets that are passed down only orally, so we must work to infiltrate the deepest echelons of this field.
We must start with its disciples. Dental school students happen to be advanced enough to be privy to these secrets of dentistry but not trained enough to resist interrogation. Thus, with contacts inside this shadowy world, we are able to uncover the ratio of enamel in baby teeth compared to adult teeth:
3/5, but its more the ratio of enamel, baby teeth have less enamel so they are more cavity prone, and they are slightly different shape and a little closer together so easier to spread cavities , and less enamel means closer to root/pulp (higher chance of baby root canals)
Hanna Nguyen, dental school student
Through Mark Zuckerberg’s Facebook Messenger, Hanna reveals that each adult tooth has approximately 1.67 times the amount of enamel that baby teeth do and there are 32 of them compared to 20 of their juvenile counterparts. This works out to approximately a 267% increase in total enamel and the same increase in toothpaste needed. Following this thread of extremely loose logic, adults need 1.1 grams of toothpaste per brushing.
Fully exploring the higher bound of our situation, we can assume that adults will brush after each of their 3 meals and will keep their toothbrushes for 4 months instead of 3, leading to a total of 384 grams or 13.5 ounces of toothpaste needed per toothbrush, nearly three times the amount in a standard 5 to 6 ounce tube.
It seems as if the average adult human can use anywhere from half a tube to over two tubes of toothpaste every time they need to replace a toothbrush, depending on their oral hygiene habit. Given this huge range in toothpaste usage it would be impossible for Big Oral Hygiene to provide exactly enough toothpaste in each tube for one toothbrush.
It’s human nature to find scapegoats for these pressing problems that plague our otherwise mundane existence. As unsatisfying of an ending as it may be, Big Oral Hygiene may actually be looking out for the interests of consumers and providing neither too much nor too little toothpaste in each of their standard sized tubes.
In exonerating Big Oral Hygiene, only two questions remain: how much toothpaste should an adult actually use? and where did the convention of a using a pea as a reference for toothpaste amount come from?
Unfortunately, both questions are outside the scope of our research and, thus, will be explored no further.
I run a website called – with tongue in cheek – Fluoride Exposed (https://fluorideexposed.org), and while doing some writing about the mysteries of fluoride toothpaste directions, I found your post. What a delight to read another person nerding out over toothpaste riddles. I plan to share your blog at some point on our #SaturdayScienceShare posts we do on our Facebook and Twitter. I, too, seek to answer where the pea as reference came from! We shall see if I can get some answers from Big Oral Hygiene 😀
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