You should do a self-check on your mouth.
Check for anything that looks like a hole or dark brown spot. (you can have a hole between your teeth, this is the main reason that you go to the dentist, because it can easily detect x-rays) however, if you see a small brown spots, that took a dentist choice (a metal tools, in the end there is a small hook/point... ) you can buy one for a few dollars and then push it to the brown area. If this position is difficult, then it's likely that it's not an empty space. If you push it down, it's soft or it causes pain, and so on, that's an empty cavity. If you have an empty cavity, you can use your tongue to contact in your mouth and feel the different positions on your teeth. If you feel a potential hole, you may want to consult a dentist for further examination. Try hot drinks and cold drinks and see how sensitive your teeth are to the temperature. If a significantly more sensitive, usually colder temperature, you might have an empty cavity. You can also use your finger or mirror to do your own house check, but it's hard to find untrained eyes. Have your dentist fix any cavities or pits on your teeth to avoid more serious dental problems.
At any rate, they are the only ones with equipment and knowledge to determine if you have cavities. Also, don't think that your money-saving method is empty, because the cost of more serious dental repairs is usually several times more expensive than common cavities.
