刷牙后漱口本来是许多人的常规操作，然而，牙医指出，不将满口泡沫冲洗干净更有益牙齿健康。如果用清水或漱口水冲洗掉泡沫，那么牙膏的防蛀作用就会大打折扣。正确做法是，将多余牙膏和泡沫吐掉即可。

After you finish brushing your teeth, swishing around some water before spitting ensures that you rid your mouth of all that frothy toothpaste. But as it turns out, having a little toothpaste residue left in your mouth isn't a bad thing—in fact, it's an important part of keeping your teeth healthy.

在你刷完牙后，你会用水漱漱口然后吐掉，这样才不会满嘴都是牙膏泡沫。然而，口腔中残留一点牙膏并不是坏事——事实上，这是保持牙齿健康的一个重要部分。

This is because toothpaste contains fluoride. "Fluoride is the single most important ingredient in toothpaste," Dr. Nigel Carter, dentist and CEO of the UK's Oral Health Foundation, explained on the organization's website. "It greatly helps oral health by strengthening the tooth enamel, making it more resistant to tooth decay. It also reduces the amount of acid that the bacteria on your teeth produce."

这是因为牙膏中含有氟化物。英国口腔健康基金会首席执行官、牙医奈杰尔·卡特博士在基金会的官网上解释道：“氟化物是牙膏中最重要的成分，没有之一。它能通过强化牙釉质来极大地改善口腔健康，从而更有效地抵抗蛀牙。氟化物还能减少牙齿上的细菌产生的酸性物质。”

If you rinse your mouth with water immediately after a brush session, you're also rinsing away the fluoride, which doesn't give it much time to work its magic. Instead, many experts recommend simply spitting out excess toothpaste. The Oral Health Foundation even launched a campaign called "Spit, Don't Rinse" in 2016 to encourage the habit.

如果你在刷牙后立刻用水漱口，你会将氟化物也冲洗掉，此时氟化物还未来得及发挥作用。因此，许多专家建议只要把多余的牙膏（泡沫）吐掉即可。为了鼓励人们养成这一习惯，口腔健康基金会甚至在2016年发起了一项名为“吐掉，别漱口”的倡议活动。

The need to completely clear your mouth after brushing can be strong, especially if you've rinsed with water for your entire life. Some people rinse with mouthwash as a workaround—but that may not be such a great idea either, since toothpaste has a significantly higher concentration of fluoride than mouthwash does. The UK's National Health Service advises gargling with mouthwash at a different time of day, like after a meal.

如果你一直以来刷牙都用水漱口，你可能难以抵制在刷牙后彻底清洁口腔的欲望。有些人会用漱口水来作为变通之法，但是这个主意也不算太好，因为牙膏的氟化物浓度比漱口水要高得多。英国国民卫生服务系统建议，在一天的其他时间用漱口水，比如饭后。