Could three be the lucky number for a healthy mouth?
Good oral hygiene is associated with a lower risk of serious conditions, including Alzheimer’s disease and rheumatoid arthritis.
And while Americans are mostly taught to brush once in the morning and once at night — for two minutes each time, followed by flossing in the evening — maintaining pearly whites looks a little different on the other side of the globe.
In South Korea, a campaign by the Korean Dental Association in the 1980s called for the “3-3-3 rule,” meaning brushing teeth three times a day, three minutes after eating, for three minutes.
The campaign caught fire. According to Korean HeraldMidday brushing is so common that there are “brushing-friendly” subway stations, cafes and malls. Some highway rest areas have toothbrush vending machines, while some department stores feature mouthwash dispensers built into their restrooms.
In 2016, more than 100 elementary, middle, and high schools were established in Seoul. Dedicated toothbrush stations.
Will these additional oral measures work, and should Americans adopt the midday brush en masse?
maybe. One study from 2017 found that those who brushed their teeth after lunch were less likely to develop gum disease than those who did not.
But a famous dentist says not so fast.
“Although it has its benefits, I don’t quite like this method.” Dr. Daniel Nissan, DDSowner and founder Bedford Dental Group In Beverly Hills, he told The Post.
“In a sense, Korean culture makes oral hygiene a daily habit, reduces plaque exposure and encourages thorough brushing, but the exact timing is not necessarily ideal.”
Nissan points out that brushing immediately after eating can be harmful, because acidic foods and drinks such as citrus fruits, soda or wine briefly weaken the surface of tooth enamel.
“Brushing too vigorously during that window can actually erode enamel because you’re temporarily scrubbing a weakened surface. That’s why dentists in the United States recommend waiting 30 to 60 minutes after eating before brushing your teeth.”
While adherence to oral hygiene is crucial, he said three times a day doesn’t beat twice, describing lunchtime brushing as “not essential”.
Likewise, three minutes of brushing may not be better than two minutes.
“Two minutes is quite enough time if you’re brushing your teeth properly. Three minutes isn’t harmful, but it’s not automatically better,” Nissan said.
He added that intense and prolonged brushing with hard-bristled brushes can actually erode enamel over time — a condition called toothbrush wear — causing teeth to appear browner, thinner, and more brittle, especially around the gum line.
Worse still, brushing too vigorously can irritate the gums to the point that they begin to pull away from the teeth, hence the phrase “long teeth.”
Nissan noted that there are some situations that may require brushing for three minutes: if you have braces, significant plaque buildup, and/or a high risk of cavities or gum disease.
Finally, he emphasizes the need for an effective electric toothbrush, daily flossing, and twice-yearly brushing.
However, the US appears to be a country more prone to splurging on tooth brushing: Surveys show that the average American forgets to brush their teeth five times a week, and when we do have access to the sink, we spend just 37 seconds on average – far less than Nissan’s professional recommendation of a full two minutes.