日常英語 怎樣正確地清潔牙齒？

我們時小候都學(xué)過該怎樣刷牙。但你知道如何清潔牙齒才最有效嗎？每天該什么時候刷牙？是否需要刷夠一定的時間，或使用一定的技巧？

We all know that cleaning our teeth is important, right? Because, if you don't clean them and things go wrong, they can cause you a lot of pain and discomfort. We're taught from a young age how to clean our teeth, but the question is – do we all clean our teeth in the same way? Is there a specific time, technique, or duration you should be incorporating into your dental routine?

When our milk teeth first appear in our infant years, we are shown, often by our parents, how to clean them – a ritual normally accompanied by some kind of catchy song. As we mature, our baby teeth drop out, replaced by adult teeth. And soon it's from trips to the dentists that we get more advice. And that's the issue – when trying to discover the best way to brush your teeth, it feels like there are so many different tips and tricks.

University College London (UCL) analysed 66 sources of toothbrushing advice from around the world. The most commonly recommended techniques incorporated circular movements and horizontal brush strokes. However, there were some deviations. The angle of the brush, use of vertical movements and rigorous scrubbing were all variations on brushing advice.

And it seems that not one single technique is the standard method – so, if that's the case, how do we know if we're doing it right? Well – there is some standard advice. It seems that brushing for between two to three minutes, two or three times a day, is the best course of action. And if you're one of these people who think it's wise to brush straight after sugary foods to prevent decay, think again. Apparently, bacteria weaken the enamel almost immediately upon eating, so it's wiser to wait for an hour or so before brushing.

So, while there is not one standardised technique, most dentists recommend a combination of horizontal and circular movements, lasting for between two to three minutes, two or three times a day. Do that, and you might not need too many trips to the dentist.