Why yellowing happens and how to prevent it.

Your teeth are covered in enamel, with dentine underneath. Dentine is naturally more yellow and becomes more visible as you age or as your enamel wears thinner. On top of that, pigments from food, drink and tobacco attach to the outside of your enamel and slowly work their way in.

These pigments are called chromogens and tannins. They are microscopically small and lodge in the tiny irregularities of your tooth surface. A thin layer of plaque speeds the process up: plaque acts like a sponge for staining compounds. Regular check-ups and professional cleanings keep this visibly in check.

The biggest culprits are coffee, black and green tea, red wine, cola, beetroot juice, curry and tomato sauce. Smoking and shisha count double: nicotine and tar leave a stubborn yellow to brown film that penetrates deep into the enamel.

Acidic drinks add to the problem. Soft drinks, sports drinks and citrus fruits soften your enamel temporarily, letting pigments seep in more easily. Never brush right after something acidic; wait half an hour and rinse with water first.

Insufficient brushing gives plaque and stains free rein. Brushing twice a day for two minutes with an electric toothbrush, daily interdental cleaning and a dental hygienist visit every six months do more for your colour than any bleaching product.

In the first 24 to 48 hours after whitening your enamel is more porous than normal. Avoid coffee, tea, wine, smoking and brightly coloured sauces during that window. Afterwards everything is allowed again, but drinking dark beverages through a straw and rinsing with water immediately significantly limits new staining.

Brush gently with a fluoride toothpaste that is not too abrasive. Whitening toothpastes with a high RDA value can actually damage your enamel over time. At Zonnelach we advise which paste suits your enamel best.

Schedule a short top-up treatment every six to twelve months. You can reuse your existing bleaching trays, only new gel is needed. That way you keep your result visible for years without going through a full course each time.