Are tooth-bleaching and other whitening products safe?

For the most part, yes. Tooth whitening does not make teeth more vulnerable to tooth decay. However, both professional and at-home bleaching can have varying degrees of success and can cause some tooth sensitivity, which can range from minor gum irritation to more serious discomfort. This generally subsides once the treatment is stopped. Professional bleaching treatments (ones that your dentist supervises) allow for a higher concentration of bleaching solution – up to about 35 per cent peroxide – than over-the-counter products. Over-the-counter treatments, such as gels and whitening strips, contain a weakened bleaching solution – commonly up to 10 per cent peroxide. While they may cause less sensitivity to the teeth and gums, they can take longer than professional bleaching to produce a whitening effect. Laser and light-activated bleaching can yield results in the course of just a few sessions, but the ADA says it has yet to see adequate safety and efficacy studies about these processes.

Do some foods weaken teeth or make them more prone to decay?

Yes. Starchy and sugary foods are the most apt to leave residue that decay-causing bacteria feed on. The bacteria, in turn, give off acids that eat into tooth enamel. What to do: Brushing right after eating a sugar- or carb-heavy treat is the best way to combat bacteria, but if you aren’t near a toothbrush, rinse your mouth out with water to help neutralise the acidity and loosen debris. Another easy solution: Pop in a piece of sugarless gum. Chewing gum revs up saliva production, which has antibacterial properties. Finally, if soda (diet or regular) is your vice, drink the fizzy stuff through a straw positioned toward the back of your mouth so that the sugary or acidic liquid bypasses most of your teeth.

My gums have been bleeding. I’ve been told it’s harmless and nothing to worry about. Are bleeding gums really harmless?

Everyone's gums bleed occasionally. Brushing too hard, especially when you have sensitive skin, can be enough to rupture your gums. However, gum-bleeding is not always a benign condition. It can be a sign of gingivitis and can lead to even more serious gum diseases. If your gums bleed, particularly if they bleed regularly, it’s time to find a dentist who can help you to rule out any cause for concern, or get you the help you need.