Most people who chew a disclosing tablet for the first time are surprised by how much colour is left on teeth they have just brushed. That is the point of the exercise. Plaque is pale and almost invisible on enamel, so a tablet that dyes it pink, red or blue turns a vague instruction ("brush better") into a map you can see in the mirror.
The dye sticks to plaque, not to clean enamel
A disclosing tablet is a chewable tablet containing a food-grade colouring. When it dissolves, the dye soaks into the sticky film of bacteria and proteins that makes up plaque, while smooth, clean enamel rinses mostly clear. Erythrosine, a red dye, has been the traditional choice, and researchers are still testing alternatives to it. Some products are two-tone: they colour thicker, more mature plaque differently from thin, fresh plaque, which hints at areas that have been missed for more than a day.
Liquids, gels and swabs work on the same principle. The format is mostly a matter of convenience, and tablets tend to be the easiest for families.
Brush first, then stain, then brush again
The order matters, because the tablet is there to test your normal routine rather than replace it.
- Brush and clean between your teeth the way you usually do.
- Chew one tablet and move the dissolved dye around your mouth for about half a minute, then spit.
- Rinse once with water and look closely in good light, including the inside surfaces and the back teeth.
- Note where the colour sits, then brush and floss again until those patches are gone.
Doing this once a week or so for a few weeks is usually enough to show a pattern. After that, an occasional check keeps the habit going.
Where the colour usually shows up
The same places come up again and again: a thin band along the gumline, the tongue side of the lower front teeth, the cheek side of the upper molars, and the gaps between teeth. These are exactly the areas where plaque irritates the gums and where it later hardens into tartar, which is explained in our guide to plaque and tartar. Plaque left at the gumline day after day is also how gum disease usually begins.
Seeing the stain is often more persuasive than being told about it. Many people adjust the angle of their brush towards the gums, slow down on the back teeth, or start cleaning between their teeth more often once they can see what was being left behind.
Children, braces and sore gums
Some groups get more out of disclosing tablets than others:
- Children learning to brush. Removing all the colour becomes a game, and parents get a quick way to check. Supervise young children so they spit the dye out, and follow the age advice on the packet.
- People with braces or other appliances. Brackets, wires and retainers create corners where plaque collects, and the dye shows them clearly.
- Anyone whose gums bleed. The colour often lines up with the areas that bleed, which tells you where to focus.
The catch: temporary staining
The dye can tint the lips, tongue and cheeks for a few hours, so tablets are best used at home in the evening rather than before going out. It can also take to tooth-coloured fillings and bonding. A 2026 laboratory study by Menekşe and Efes in the European Oral Research journal found that two disclosing agents changed the colour of several composite filling materials, and one two-tone product caused changes large enough to be noticeable. If you have front fillings or bonding, ask your dentist or OHT whether a disclosing product is suitable for you.
The dyes are used in small amounts and are considered safe for most people. If you have a known reaction to a food colouring, check the ingredients first.
A coaching tool, not a clean
A tablet shows plaque. It does not remove it, and it cannot shift tartar or find decay. Brushing twice a day with fluoride toothpaste, cleaning between the teeth, and regular check-ups with a dentist or OHT still do the real work.
Common questions
Will a disclosing tablet stain my teeth permanently?
No. The colour sits in the plaque and comes away when the plaque is brushed off. Any tint on the tongue or lips usually fades within a few hours. Tooth-coloured fillings are the main exception, as noted above.
How often should I use them?
Weekly while you are working on your technique is plenty. Once your teeth come up mostly clean, an occasional check is enough.
Can I ask for this at my check-up?
Yes. Many dental teams use a disclosing solution during a hygiene visit, and asking for it is a good way to see where your routine falls short before the clean begins.
Our dentists and oral health therapists can go over your brushing and cleaning with you at your next visit. See our current offers or book with our general dentists in Melrose Park.
