| Recorded at | October 17, 2016 |
|---|---|
| Event | TED-Ed |
| Duration (min:sec) | 04:43 |
| Video Type | TED-Ed Original |
| Words per minute | 165.17 slow |
| Readability (FK) | 35.83 very difficult |
| Speaker | Mel Rosenberg |
Official TED page for this talk
Synopsis
When a team of archeologists recently came across some 15,000-year-old human remains, they made an interesting discovery: the teeth of those ancient humans were riddled with holes. So what causes cavities, and how can we avoid them? Mel Rosenberg takes us inside our teeth to find out. [Directed by Andrew Foerster, narrated by Addison Anderson, music by Devin Polaski].
| 1 | 00:07 | When a team of archaeologists recently came across some 15,000 year-old human remains, they made an interesting discovery. | ||
| 2 | 00:15 | The teeth of those ancient humans were riddled with holes. | ||
| 3 | 00:19 | Their cavities were caused by the same thing that still plagues us today, specific tiny microbes that live in our mouths. | ||
| 4 | 00:28 | These microbes are with us soon after birth. | ||
| 5 | 00:30 | We typically pick them up as babies from our mothers' mouths. | ||
| 6 | 00:34 | And as our teeth erupt, they naturally begin to accumulate communities of bacteria. | ||
| 7 | 00:39 | Depending on what we eat, and specifically how much sugar we consume, certain microbes can overpopulate and cause cavities. | ||
| 8 | 00:48 | Diets high in sugary foods cause an explosion of bacteria called mutans streptococci in our mouths. | ||
| 9 | 00:55 | Like humans, these microorganisms love sugar, using it as a molecular building block and energy source. | ||
| 10 | 01:03 | As they consume it, the bacteria generate byproducts in the form of acids, such as lactic acid. | ||
| 11 | 01:09 | Mutans streptococci are resistant to this acid, but unfortunately, our teeth aren't. | ||
| 12 | 01:16 | While each human tooth is coated in a hardy, protective layer of enamel, it's no match for acid. | ||
| 13 | 01:22 | That degrades the armor over time, leaching away its calcium minerals. | ||
| 14 | 01:28 | Gradually, acid wears down a pathway for bacteria into the tooth's secondary layer called the dentin. | ||
| 15 | 01:35 | Since blood vessels and nerves in our teeth are enclosed deep within, at this stage, the expanding cavity doesn't hurt. | ||
| 16 | 01:43 | But if the damage extends beyond the dentin, the bacterial invasion progresses causing excruciating pain as the nerves become exposed. | ||
| 17 | 01:52 | Without treatment, the whole tooth may become infected and require removal all due to those sugar-loving bacteria. | ||
| 18 | 02:00 | The more sugar our food contains, the more our teeth are put at risk. | ||
| 19 | 02:04 | Those cavemen would hardly have indulged in sugary treats, however, so what caused their cavities? | ||
| 20 | 02:11 | In meat-heavy diets, there would have been a low-risk of cavities developing because lean meat contains very little sugar, but that's not all our early human ancestors ate. | ||
| 21 | 02:22 | Cavemen would also have consumed root vegetables, nuts, and grains, all of which contain carbohydrates. | ||
| 22 | 02:29 | When exposed to enzymes in the saliva, carbohydrates get broken down into simpler sugars, which can become the fodder for those ravenous mouth bacteria. | ||
| 23 | 02:40 | So while ancient humans did eat less sugar compared to us, their teeth were still exposed to sugars. | ||
| 24 | 02:47 | That doesn't mean they were unable to treat their cavities, though. | ||
| 25 | 02:50 | Archaeological remains show that about 14,000 years ago, humans were already using sharpened flint to remove bits of rotten teeth. | ||
| 26 | 03:00 | Ancient humans even made rudimentary drills to smooth out the rough holes left behind and beeswax to plug cavities, like modern-day fillings. | ||
| 27 | 03:10 | Today, we have much more sophisticated techniques and tools, which is fortunate because we also need to contend with our more damaging, sugar-guzzling ways. | ||
| 28 | 03:20 | After the Industrial Revolution, the human incidence of cavities surged because suddenly we had technological advances that made refined sugar cheaper and accessible. | ||
| 29 | 03:31 | Today, an incredible 92% of American adults have had cavities in their teeth. | ||
| 30 | 03:37 | Some people are more susceptible to cavities due to genes that may cause certain weaknesses, like softer enamel, but for most, high sugar consumption is to blame. | ||
| 31 | 03:46 | However, we have developed other ways of minimizing cavities besides reducing our intake of sugar and starch. | ||
| 32 | 03:53 | In most toothpastes and many water supplies, we use tiny amounts of fluoride. | ||
| 33 | 03:59 | That strengthens teeth and encourages the growth of enamel crystals that build up a tooth's defenses against acid. | ||
| 34 | 04:06 | When cavities do develop, we use tooth fillings to fill and close off the infected area, preventing them from getting worse. | ||
| 35 | 04:13 | The best way to avoid a cavity is still cutting down on sugar intake and practicing good oral hygiene to get rid of the bacteria and their food sources. | ||
| 36 | 04:23 | That includes regular tooth brushing, flossing, and avoiding sugary, starchy, and sticky foods that cling to your teeth between meals. | ||
| 37 | 04:31 | Gradually, the population of sugar-loving microbes in your mouth will decline. | ||
| 38 | 04:36 | Unlike the cavemen of yesteryear, today we have the knowledge required to avert a cavity calamity. | ||
| 39 | 04:41 | We just need to use it. |