The conventional wisdom says that you should brush your teeth after meals or at least twice a day to avoid tooth decay. But it doesn’t follow that so long as you brush regularly, you’ll get no cavities. A number of other factors work together to determine this – things such as dietary habits and genetic susceptibility. It’s also not just important that you brush. How you brush matters just as much.
For instance, if you don’t brush long enough or with the brush properly angled, you may leave some of the biofilm (plaque) intact. This lets it keep on colonizing and raising the risks of tooth decay. On the other hand, if you brush too aggressively, you can damage the gingival tissues (gums) to the point of exposing some of the tooth root, leaving the tooth “sensitive” – typically to sweet, hot or cold foods.
Another cause of sensitivity is erosion of or damage to the tooth enamel. This damage can come from excess intake of acidic foods and beverages – especially energy and sports drinks, and soda. In themselves, these can damage teeth (for more info, see this and this and this ), but even more so if you brush shortly after consuming these high acid substances.
Similarly, sodium lauryl sulfate (SLS) – a foaming agent commonly used in mass market toothpastes – can damage the soft tissues of the mouth (again, the gums), as can fluoride. The damage may further contribute to gum recession and sensitivity.
So how do you brush correctly?
If eating or drinking highly acidic foods, wait at least a half hour after consumption before brushing your teeth.
Use a soft-bristled brush.
Use a toothpaste that is SLS-free, as well as fluoride-free.
When you brush, do so for two minutes, or 30 seconds on each quadrant. Keeping the brush at a 45º angle to the gum line, brush towards the top of each tooth. Clean each tooth individually, overlapping as you move through your mouth. In front, where your dental arches narrow and curve, use the tip of your brush.