You might be aware of the fact that the brown discoloration at the base of your teeth (where they meet your gums) is likely to be plaque and tartar ( which is hardened plaque). But being aware and being concerned are two different things. Can't you just disguise the discoloration by whitening your teeth? 

Antiseptic Properties of Bleach

It might seem like this course of action has some logic. After all, plaque and tartar have their origins in the oral bacteria that inhabit your mouth. Since hydrogen peroxide (bleach) is the active ingredient in most teeth whitening gels, and bleach has antiseptic properties, wouldn't whitening be a good way of managing the oral bacteria that cause plaque and tartar? Unfortunately, it's not quite so simple.

Hardened Biofilm on Your Teeth

Dental plaque itself is a biofilm on your teeth, and it's made up of oral bacteria. Plaque can be controlled with regular brushing and interdental cleaning (which is cleaning the spaces between your teeth). If plaque isn't removed, it calcifies (hardens) and becomes tartar—which can't be removed with your toothbrush. Tartar often forms at the gum line and can be light brown in color (or sometimes yellow). Just because it's a discoloration, this doesn't mean it can be removed by bleaching your teeth.

Irritated Gums, Corroded Teeth

The oral bacteria present in tartar will begin to infect your gums, and you'll develop gingivitis. This means that whitening your teeth will irritate your inflamed gum tissues, and often significantly so. The cariogenic (cavity-causing) bacteria in tartar can also be actively corroding your teeth, which is another reason why whitening your teeth is unwise at the moment. So what should you do to whiten your teeth while also making sure that you're not harming them?

Scaling Before Whitening

If you schedule a whitening treatment at a cosmetic dentistry office, they will inspect your teeth before proceeding. If tartar is noted, your teeth will need to be professionally cleaned. This is all that's needed to remove your hardened plaque, and the dentist will use a scaling tool to gently scrape the tartar away without harming the underlying tooth structure. Once your tartar has been removed, the dentist can whiten your teeth.

You shouldn't attempt to conceal tartar by whitening your teeth. If you still wish to whiten your teeth, any cosmetic dentist can do this for you, and you will definitely need to see a dentist—since tartar removal must be performed before your teeth can be whitened.

If you want to continue reading more about this, check out a variety of cosmetic dentistry clinic websites.