How can some one know is his or her teeth are healthy?

See a dentist: You can't do a thorough inspection of your own mouth, so you need to see a dentist to have your teeth and gums checked. Do this every 6 months.

Dentist: I agree you need to see your dentist. They will do a complete exam with a full set of x-rays. This way they can determine the health of your mouth.

Regular Dental Visit: The best way to determine if your teeth are healthy is to have your dentist give you a comprehensive oral exam along with an imaging study (x-rays). Once their status is established, any problems fixed, than routine visits for exams and professional maintenance will allow updated status reports! and don't forget, you're responsible for over the top hone care to insure great checkups!