White Spots on Teeth: Causes, Whitening and Treatment

White spots on teeth are most often a sign that the enamel in that area has lost some of its minerals, usually because plaque has sat there for a while, for example around braces. Other common reasons are fluorosis (too much fluoride while the teeth were forming in childhood) and enamel hypoplasia (enamel that did not form fully). Many white spots can be improved or hidden, but the right treatment depends on the cause, so it is worth having them checked by a dentist before trying whitening.

Why do white spots appear on teeth?

Enamel is the hard, slightly translucent outer layer of the tooth. When part of it is less mineralised or formed differently from the rest, light passes through it differently and it looks chalky, opaque or brighter white than the surrounding tooth. The main causes are below.

1. Early decay (demineralisation)

The bacteria in plaque produce acids every time you eat or drink something sugary or starchy. If plaque is left on one area for long enough, those acids draw minerals out of the enamel and leave a dull, chalky white patch. This is the earliest stage of tooth decay, before a cavity has formed.

These spots are common:

• Around the brackets after braces come off, where plaque was hard to clean
• Along the gum line, where brushing is often rushed
• In people who sip sugary or acidic drinks through the day

The good news is that at this early stage the enamel surface is often still intact and the process can be slowed or partly reversed. Left alone, the area can break down into a cavity.

2. Dental fluorosis

Fluorosis happens when a child takes in more fluoride than needed while the permanent teeth are still forming under the gums, roughly up to the age of eight. Sources can include drinking water that is naturally high in fluoride (an issue in some parts of India), swallowing toothpaste, or supplements. Mild fluorosis shows as faint white lines, flecks or patches, often on several teeth in a symmetrical pattern. More severe cases can show brown staining or pitting. Fluorosis is a cosmetic concern rather than a disease, and once the teeth have formed it does not get worse.

3. Enamel hypoplasia and similar developmental defects

Sometimes enamel does not form fully or evenly. This can follow illness or high fever in early childhood, premature birth, nutritional problems, or an injury or infection affecting a baby tooth that sits over the developing adult tooth (sometimes called Turner's tooth). The result can be white, cream or yellow-brown patches, or areas of thinner enamel. These teeth may be more sensitive and more prone to decay, so they need regular checking.

4. Plaque, tartar and dehydration

Not every white mark is in the enamel itself. A soft whitish layer on the teeth is usually plaque, which brushes off. Hard white or yellow deposits near the gums, especially behind the lower front teeth, are often tartar (calculus), which only a professional cleaning can remove. Teeth can also look temporarily chalky and white after a long dental appointment, or when you wake up after sleeping with your mouth open, because the enamel has dried out. That kind of whiteness fades within an hour or so.

What does a white line on the teeth mean?

A white line running across a tooth, especially near the gum, is often early demineralisation where plaque collects. Fine horizontal white lines across several teeth are more typical of mild fluorosis. Faint lines can also be normal growth lines in the enamel. A dentist can usually tell the difference by looking closely at the tooth after it is cleaned and dried.

Can teeth whitening remove white spots?

This is the most common question, and the honest answer is: not on its own, and not straight away. Whitening lightens the overall colour of the tooth. In the first days after whitening, white spots often look more noticeable, because the tooth around them is lighter and the enamel is temporarily dehydrated. As the teeth settle over the following weeks, the contrast often softens and the spots may blend in better with the brighter tooth.

For some people with mild spots, whitening as part of a wider plan gives a good overall result. For others, it simply makes the patches stand out. That is why it is worth having the cause diagnosed before booking teeth whitening. If there is active early decay, that needs to be addressed first.

How are white spots on teeth treated?

Treatments range from very gentle to more involved. Your dentist will usually start with the least invasive option that suits the cause.

• Remineralisation. For early decay spots, the first step is to stop the cause and help the enamel regain minerals: better cleaning around the area, fluoride toothpaste, professionally applied fluoride varnish and, in some cases, other remineralising products. Spots can become less visible over months, although they do not always disappear.
• Resin infiltration. A minimally invasive technique for some early decay and mild developmental spots. The porous enamel is gently treated and then filled with a clear, flowable resin, which changes how light passes through it so the spot blends in. No drilling is needed.
• Microabrasion. A mild acid and a fine abrasive paste remove a very thin surface layer of enamel, which can reduce shallow white marks such as mild fluorosis. It is often combined with whitening.
• Composite bonding. For deeper spots, a small amount of tooth-coloured resin is used to cover or replace the affected area.
• Veneers. When spots are deep, widespread or combined with other concerns about shape or colour, thin ceramic or composite veneers can cover the front of the teeth. This is usually considered only after simpler options. Read more on our smile makeover and veneers page.

How to prevent white spots

• Brush twice a day for two minutes with a fluoride toothpaste, paying attention to the gum line.
• Clean between your teeth daily.
• If you wear braces or aligners, be especially careful around brackets and attachments, and keep up your hygiene visits.
• Keep sugary snacks and drinks to mealtimes rather than sipping or grazing through the day.
• For children, use a smear of toothpaste for under-threes and a pea-sized amount after that, supervise brushing, and teach them to spit rather than swallow.
• If you are unsure about the fluoride level in your water, ask your dentist before giving any fluoride supplements to children.

When should you see a dentist about white spots?

Book a check-up if:

• A white spot is new, or is growing
• A spot is turning yellow, brown or grey, or feels rough
• The tooth is sensitive or painful
• White spots appeared after braces came off
• Your child's new adult teeth have white or discoloured patches
• You are planning whitening and want to know how the spots will respond

At The Sterling Dental Clinic in Vasant Vihar, a dentist can examine the spots, explain what is causing them and talk you through the options, from simple remineralisation to cosmetic treatment. If the spots are linked to plaque around the gums, a professional clean and advice from our gum care team can help too.