24 months in the life of your teeth

Fewer than half of London adults are signed up with a state dentist. So what typically happens if you go without a check-up for two years? by Anastasia Stephens finds out

After one week

Plaque starts to build up the moment you leave the dentist - 75 to 100 different types of bacteria in your mouth begin to settle to form a thin film on your teeth. If you eat a high-carbohydrate diet or sugary foods during the day, bacterial populations can explode within an hour - a sweet fizzy drink can result in four to five times the plaque levels of a person who has eaten oily food or protein.

A thorough brushing twice a day will get rid of around 90 per cent of plaque. But, on average, 10 per cent will be left around your gum margins or between your teeth every day.

After two weeks

Although your mouth and teeth will be generally healthy, foodtraps will be feeding small colonies of bacterial plaque, left behind after brushing. (Flossing between your teeth at night helps prevent this.) But even if your toothbrush sweeps away food residue the next morning, the bacteria and saliva will have mixed to become thicker, stickier areas of plaque.

People with overcrowded teeth, crowns or bridges will be more prone to plaque build-up as they cannot brush trapped bacteria away as easily.

After one month

According to dental expert Professor Maria Rodriguez, one month is a critical point for plaque formation. "At around this stage it becomes thick and sticky enough to trap tiny food particles on which bacteria feed," she says. "Because of this, the bacterial colonies become self-sufficient and more damaging to your oral health."

If you smoke or drink coffee or wine, dark particles get trapped and staining begins.

After Three Months

Bacterial plaque will have thickened and calcified, meaning that you can no longer brush it off. "Plaque will have also grown below the gum margin where bacteria release toxins which kill cells, break down tissue and cause inflammation," explains Professor Rodriguez.

At this stage, if you haven't brushed thoroughly, your gums may occasionally bleed - a sign of early gum disease. Since bacteria release sulphurous compounds, your breath may begin to smell. In people who don't floss, who sometimes go to bed without brushing their teeth or eat lots of sweet food, small brown spots - early signs of caries (decay) - may begin to appear on tooth enamel.

After Six Months

By now, even in people who brush and floss thoroughly, it's quite likely that bacteria will be established under the gums. Here, the dark, moist environment, containing trapped food and little oxygen, is the perfect environment for the most harmful type of bacteria.

"These 'gram negative' bacteria release toxins that can break down both gum tissue and bone," says Mervyn Druian, a north London dentist and spokesman for the British Dental Association.

He explains: "The bacteria release toxins that create pockets under the gums and begin to dissolve bone." This can start happening at six months - well before gums become inflamed and red, a classic sign of gum disease. At this stage tooth decay may have spread through the enamel into softer tooth tissue underneath.

After 12 months

While good oral hygiene helps avoid cavities, in 12 months they may have formed in people who don't brush well and also have a high-carbohydrate diet.

Bacterial plaque above and below the gums is likely to be causing some degree of bad breath, whether you brush well or not. Bacteria may have caused deeper pockets beneath the gums and some bone will have been lost in most people. More importantly, gum infection could be causing problems elsewhere in the body.

"When gums bleed, the bacteria can get into the circulation and cause tiny clots, raising the risk of heart attack and stroke," explains Professor Rodriguez. "They can cause infection of the heart muscle and significantly increase the risk of premature birth in pregnant women."

After 18 months

Most people will be experiencing bleeding each day or every other day because of chronic gum inflammation. You may have sour breath and a sour taste in your mouth during the day because of all the sulphur compounds released by bacterial plaque. Pockets between your gum margin and teeth will be getting deeper - possibly by 1mm per six months - depending on the level of gum infection.

Because smoking reduces blood supply to the gums, regular smokers are less likely to experience bleeding, but that doesn't mean they don't have gum disease. In fact, smoking promotes inflammation and prevents healing, so tends to make gum disease worse.

Ater two years

Even if you have brushed thoroughly and flossed your teeth for two years, you are likely to have red, inflamed gums, bad breath and some degree of bone loss - all as a result of not having plaque removed from beneath your gums. While you may have escaped caries, those with less thorough oral hygiene may have developed deep and infected cavities.

People who don't use toothpaste containing fluoride are likely to have weaker teeth and more cavities, as are those who regularly consume sugary drinks.

After two years - whether the problem is bleeding gums, sour breath or aching - there's likely to be some sign that a visit to the dentist is needed.