Not all tooth stains are the same.

Understanding the type of staining affecting your smile is the first step towards choosing the most effective whitening treatment. Some stains vanish with a professional clean, whilst others require more advanced intervention.

1. Extrinsic stains (surface-level discolouration)

Extrinsic stains are the most common type of tooth discolouration and, fortunately, the easiest to address. These stains sit on the surface of your tooth enamel, affecting only the outermost layer of your teeth.

What causes extrinsic stains?

Think of extrinsic stains as the daily accumulation of pigmented substances that latch onto your tooth enamel. Common culprits include:

Foods and drinks:

• Coffee and tea (particularly black tea)
• Red wine
• Cola and dark fizzy drinks
• Berries (blueberries, blackberries, cherries)
• Tomato-based sauces
• Soy sauce and balsamic vinegar
• Curry and heavily pigmented foods

Lifestyle factors:

• Smoking and tobacco use (the biggest offender)
• Poor oral hygiene allowing plaque buildup
• Inadequate brushing and flossing

The good news? Because extrinsic stains only affect the tooth’s surface, they respond brilliantly to professional whitening treatments.

How extrinsic stains are treated

• Professional cleaning: A hygienist can remove surface stains through scaling and polishing, restoring your teeth’s natural colour.
• Professional teeth whitening: LED light-activated teeth whitening penetrates the enamel to break down stain molecules, delivering dramatic results in just 60 minutes.
• At-home maintenance: Using whitening toothpaste (sparingly) and maintaining excellent oral hygiene can help prevent new stains from forming.

Prevention tips

• Rinse your mouth with water after consuming staining foods or drinks.
• Use a straw for beverages like coffee, tea, and wine.
• Brush your teeth 30 minutes after eating (wait to avoid brushing when enamel is temporarily softened by acids).
• Quit smoking – your teeth (and overall health) will thank you.
• Attend regular dental hygiene appointments.

2. Intrinsic stains (discolouration from within)

Unlike extrinsic stains that sit on the surface, intrinsic stains originate from within the tooth structure itself. These stains affect the dentin – the layer beneath your enamel – making them more challenging to treat.

What causes intrinsic stains?

Intrinsic stains develop due to internal factors that alter the tooth’s structure or composition:

During tooth development:

• Excessive fluoride exposure in childhood (dental fluorosis)
• Tetracycline antibiotics taken during pregnancy or early childhood
• Genetic conditions affecting tooth formation

After teeth have developed:

• Tooth trauma or injury damaging the internal structure
• Root canal treatment (teeth may darken over time)
• Certain medications
• Dental materials from old fillings leaching into the tooth
• Internal tooth decay

Intrinsic stains often appear as yellow, brown, grey, or even bluish discolouration. They’re notoriously stubborn because the staining is deeply embedded in the tooth structure.

How intrinsic stains are treated

• Professional whitening: Whilst more challenging than extrinsic stains, some intrinsic stains do respond to professional bleaching treatments, particularly if they’re not too severe. Brown and yellow intrinsic stains typically respond better than grey or blue ones.
• Internal bleaching: For teeth that have darkened after root canal treatment, dentists can perform internal bleaching by placing whitening gel inside the tooth.

When whitening isn’t effective enough, cosmetic treatments can mask the discolouration:

• Dental bonding (tooth-coloured resin applied to the tooth surface)
• Porcelain veneers (thin shells covering the front of teeth)
• Dental crowns (for severely discoloured teeth)

Prevention tips

• Avoid tetracycline antibiotics during pregnancy and in young children.
• Monitor fluoride intake in children to prevent fluorosis.
• Wear a mouthguard during contact sports to prevent tooth trauma.
• Address dental issues promptly before they cause internal discolouration.

3. Age-related stains (the inevitable combination)

Age-related staining is exactly what it sounds like – discolouration that accumulates over decades of life. However, it’s not a separate category so much as a combination of both extrinsic and intrinsic factors working together over time.

What causes age-related stains?

As we age, several changes occur that affect tooth colour:

• Enamel thinning: Years of chewing, grinding, and general wear gradually thin the enamel layer, allowing the naturally yellow dentin beneath to show through more prominently.
• Dentin darkening: The dentin itself naturally yellows and darkens as we age, compounding the problem.
• Accumulated stains: Decades of exposure to staining substances mean extrinsic stains have had plenty of time to work their way deeper into the tooth structure, essentially becoming intrinsic stains.
• Lifestyle factors: Years of coffee consumption, red wine, smoking, or other staining habits take their cumulative toll.

Age-related discolouration is progressive. You might not notice much change in your twenties and thirties, but by middle age, the effects become more apparent.

How age-related stains are treated

Because age-related staining involves both surface and internal discolouration, treatment often requires a comprehensive approach:

• Professional whitening: Still the first line of defence and remarkably effective, even for age-related stains. Modern LED whitening treatments can lighten teeth by 6-8 shades.
• Combination treatments: Some cases benefit from combining whitening with cosmetic procedures like veneers or bonding for optimal results.
• Regular maintenance: Age-related staining responds well to treatment, but maintaining results requires ongoing care and possibly periodic touch-ups.

Prevention and management tips

• Start good oral hygiene habits early and maintain them throughout life.
• Limit exposure to staining substances when possible.
• Visit your hygienist regularly for professional cleanings.
• Consider whitening treatments before stains become deeply embedded.
• Protect your enamel by avoiding excessive acid exposure and grinding.

Which type of stain do you have?

Often, people have a combination of stain types. You might have surface stains from your morning coffee, plus deeper age-related discolouration. Or you may have mostly extrinsic stains with one intrinsic stain from an old injury.

The best way to identify your stain type is through a professional consultation. A qualified dentist can:

• Examine your teeth thoroughly
• Determine the primary cause of discolouration
• Recommend the most effective treatment approach
• Set realistic expectations about results

The good news? Most stains respond to professional treatment

Regardless of which type of staining you’re dealing with, professional teeth whitening can make a significant difference.

Extrinsic and age-related stains typically respond beautifully to LED light-activated whitening, whilst even some intrinsic stains can be lightened with the right approach.

What’s crucial is choosing professional treatment over DIY methods. Professional whitening:

✓ Treats all three types of stains effectively
✓ Uses safe, regulated concentrations
✓ Includes proper diagnosis of your stain type
✓ Delivers predictable, lasting results
✓ Protects your enamel throughout the process

Over-the-counter products simply can’t match these benefits. They lack the strength to tackle anything beyond the lightest surface stains and offer no professional guidance on what type of staining you’re actually dealing with.

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Wondering which type of stain is affecting your smile? Book a free consultation at Harley Teeth Whitening. Our GDC-registered dentists will assess your teeth, identify your stain type, and recommend the most effective treatment to restore your bright, confident smile.