If you are going to use toothpaste to try and clean your face, you should check the ingredients on the tube before you go any further. A number of the ingredients commonly found in toothpaste can significantly irritate your skin.  If your toothpaste contains sodium lauryl sulfate, triclosan, and/or sodium fluoride, then think again about using it. These ingredients in particular are known as irritants to the skin. Ingredients such as calcium carbonate and zinc can have a more positive effect on your skin, but these can be found in specialist treatments which don't include the irritants.  Plain white toothpaste may contain fewer irritants than clear gels. If you decide to proceed with using toothpaste, it's sensible to test it out first. Apply small amounts to your skin in a few different places. If your skin reddens, becomes excessively dry or discoloured you should not continue to use toothpaste directly on your skin.  If you don't have a bad reaction, apply a small amount to a spot and allow it dry. You can use a q-tip do this. If you use your fingers, be sure to wash your hands first. Keep an eye on your skin around the toothpaste. If it becomes irritated or sore, wash it off immediately. Given that the benefits of using toothpaste on spots are unclear at best, the amount of time you need to leave it on your skin is not fixed. Some people leave the toothpaste on overnight, but if you have sensitive skin this prolonged exposure could cause irritation. Be conservative in order to minimise the risks of damaging your skin.  When you wash it off, use warm water and a gentle circular motion. Splash some cool water on your face and apply a moisturiser if you skin feels tight and dry.

TL;DR in Vietnamese:
Kiểm tra thành phần của kem đánh răng. Thoa một lượng nhỏ kem đánh răng lên da đã rửa sạch. Rửa sạch kem đánh răng.