Q: What is the best time to brush your teeth?

　　问：什么时候刷牙最好?

　　Answered by Scott Frey

　　Scott Frey的回复：

　　The best time to brush your teeth isin the morning before breakfast.However, it certainly isn't the only time you should brush throughout the day.

　　早饭之前刷牙最好，但一天肯定不止刷这一次。

　　There are several reasons for this:

　　原因有以下几点：

　　1. Salivary calcium levels are lowest in the morning. Thus, your teeth are at a much higher risk of acidic damage from bacteria and dietary acids in the morning than at any other time. Brushing kickstarts salivary flow that has been reduced overnight and adds in fluoride to the mix which will help buffer against acids.

　　早上唾液中的钙含量最低。因此，牙齿受细菌和酸性食物伤害的风险是一天中最高的。刷牙能让前一晚减少的唾液加速分泌，并且，牙膏里的氟化物与唾液混合后，能够有效减缓酸性伤害。

　　2. Bacteria take seconds to begin to metabolize sugars into acids. Clearing them out before the introduction of food makes far more sense than brushing after they have already soaked up sugars and produced acids especially considering point #1.

　　细菌只用几秒钟就能让糖份开始代谢为酸性物质。吃东西前就把细菌清理干净，要比它们已经大量摄取糖分，并产生酸性物质后再刷牙明智得多，尤其是在考虑到第一点的情况下。

　　3. Bacteria have been multiplying overnight in an environment characterized by reduced salivary flow.

　　夜间唾液分泌减少，经过一整晚，细菌已在口腔内大量繁殖。

　　4. Acidic foods and drinks will soften your enamel and make you teeth more vulnerable to toothbrush abrasion if brushing immediately after meals. Toothbrush abrasion and erosion are becoming increasingly common so we need to pay greater mind. Scrubbing on your teeth when your enamel has been softened up by something like OJ will lead to toothbrush abrasion and increased sensitivity of your teeth.

　　酸性食物和饮料会软化牙釉质，如果饭后立刻刷牙，牙齿会更容易受到牙刷的磨损。如今，牙刷造成的磨损和侵蚀变得越来越普遍，我们应该多加重视。牙釉质被橙汁之类的东西软化时，用力刷牙会导致牙磨损，让你的牙齿更加敏感。

　　The process of enamel demineralization occurs much more rapidly than remineralization,so it is extremely important to take steps to limit the extent of demineralization throughout the day so your teeth can recover.

　　牙釉质脱矿的速度比再矿化的速度快得多。所以在一整天中，采取措施减少牙釉质受损极为重要，这样牙齿才有时间自我修复。

　　If the issue is how toothpaste impacts your appreciation for breakfast, use a SLS-free toothpaste because SLS affects your tastebuds and makes things taste odd (you should be using an SLS-free toothpaste for other reasons).

　　如果问题在于牙膏影响了你早餐的食欲，那就使用不含硫酸月桂酸钠(SLS)的牙膏吧。硫酸月桂酸钠会影响你的味蕾，东西吃起来味道就怪怪的。出于其他一些原因，你也应该使用不含硫酸月桂酸钠的牙膏。