Even if you brush and floss your teeth faithfully, it is important that you have your teeth professionally cleaned on a regular basis. (Of course, if you aren't quite so meticulous about your oral hygiene, it's even more important!) After a thorough cleaning, your teeth will feel smooth and squeaky-clean, and they will probably look a lot brighter too. But professional teeth cleanings aren't done for looks alone.
Why do your teeth need this kind of attention? Essentially, it's because over time they tend to build up a layer of plaque (a sticky, bacteria-rich film) and hard deposits (called tartar, or calculus) that are very difficult to remove without special tools. When these deposits are allowed to remain on the tooth surfaces or below the gum line, they provide ideal conditions for bacteria to grow and multiply. The acids produced by some bacteria cause tooth decay and gum disease; if left uncontrolled, this can lead to inflammation and infection of the gums, and possibly influence systemic (whole body) diseases.
Dentists have a special term for preventive procedures like tooth cleaning: prophylaxis, from the Greek word meaning to protect or guard against. In this case, the focus is on preventing tooth decay and gum disease. Performed in conjunction with a routine dental examination, a professional cleaning can go a long way toward controlling these two common maladies. While your teeth are being cleaned, it's also a good opportunity to take a close look at your oral health in general and check for a few specific problems.