Teeth whitening

I fear going to the dentist which is exactly why I dutifully visit every six months for preventive care and maintenance. For me, no cavities mean no injections, no drilling, no filling, no pain.

Along the way, there are still several factors which work against us keeping pearly whites, white. Some of those factors, like age, or having poor original teeth colour, are not preventable. But when it comes to teeth colour, there are preventive lifestyle steps we can take early, at least to retain teeth colour close to the one we originally had.

Tooth-staining suspects

Diet - food and drink may cause tremendous staining over time. Coloured foods and drinks like dark tea, coffee, dark cola and red wine, cranberry juice, carrots, beets, curry, tomato sauce and soy sauce discolour our teeth.

Smoking - Nicotine leaves brown deposits on teeth which penetrate into the enamel.

Medications - These include tetracycline (an antibiotic), iron supplements, and chlorhexidine (an ingredient in some mouthwashes).

Age - Over time we accumulate stains many of which are absorbed and become stubborn to remove.

Injury - this may cause permanent discoloration.

Original Colour - Our inborn tooth colour is usually ivory-white but colours may range from butter - yellow to grey.

Bleaching the teeth

So to begin with, our teeth are not actually white, but whiter-than-white is the shade we strive for. The aim of teeth whitening is to lighten whatever shade we have.

The enamel (outer layer of teeth) is translucent (partially see-through), so the colour of our teeth is largely determined by the colour of the inner layer (dentine) of the teeth. Enamel is also pretty porous, so the bleaching agent can go straight through to dentine.

Bleaching may take the form of applying a chemical directly to the surface (enamel) of teeth, or using a form of light plus heat, to speed up the bleaching process when the chemical is applied.

The main ingredient you'll find in teeth-bleaching products is carbamide peroxide (10 to 44 per cent strength). A gel containing the bleaching agent is applied to custom-made mouth guard (application tray) which is fitted to teeth for a specified time. Two or three such treatments are necessary for obvious results. Results vary and positive results don't last forever.

Don't try this at home

Most dental experts suggest that we laymen do not attempt to bleach our teeth outside of the dentist's chair. Some persons are sensitive to bleaching agents. Prolonged exposure to bleaching agents may damage tooth enamel.

Bleaching agents used at high strength may damage gums and mucous membranes inside the mouth and make the teeth really sensitive to heat or cold. "How much is too much?'' is a question I would want answered before I embark on self-administered bleaching.

Dr Dahlia McDaniel is a pharmacist with a doctorate in public health. She is the chief executive officer of two pharmacies and a medical practice in Kingston. Email:yourhealth@gleanerjm.com.