This post was written by Christchurch Dental

Tooth staining most often comes from pigments and tannins in everyday foods and drinks, natural ageing, tobacco, plaque buildup, and certain medical or dental factors.

Tooth staining is one of the most common cosmetic concerns, and understanding why it happens can help you protect your smile and make informed choices about prevention and treatment.

The Most Common Causes of Tooth Staining

Everyday foods and drinks are the leading contributors to extrinsic (external) staining. Pigments settle on enamel and gradually dull its brightness. Common culprits include:

• Tea, coffee, red wine, cola, and dark fruit juices
• Curries, soy sauce, berries, beetroot, tomato-based sauces, and spices
• Tobacco, where nicotine and tar create yellow-brown staining that becomes harder to remove over time
• Mouthwashes containing chlorhexidine, which can stain with regular/over-use
• Plaque and tartar, which trap pigments and darken teeth

Ageing and Natural Changes

As we age, enamel becomes thinner and more translucent, allowing more of the naturally yellow dentine to show through. Enamel also becomes more porous over time, making it easier for pigments to bind to the tooth surface.

Oral Health and Medical Factors

Several dental and medical conditions can influence tooth colour:

• Dental trauma, which may darken a tooth if the nerve is affected
• Decay or leaking restorations, which can cause localised discolouration
• Root canal–treated teeth, which may darken later without cosmetic management
• Tetracycline antibiotics in childhood, causing intrinsic (internal) banding
• Fluorosis, producing white flecks or brown patches
• Conditions affecting enamel or dentine formation

Extrinsic vs Intrinsic Staining

Dentists classify staining into two types:

• Extrinsic stains – on the enamel surface, usually from food, drink, tobacco, or plaque
• Intrinsic stains – within the tooth structure, often due to ageing, trauma, medications, or developmental conditions

Extrinsic stains respond well to hygiene cleaning – especially when using Airflow. Intrinsic stains may require tooth whitening, veneers, or other cosmetic options.

What Are Tannins—and Why Do They Stain Teeth?

Tannins are naturally occurring plant compounds found in tea, coffee, wine, berries, and dark chocolate.

Tannins:

• Increase the ability of chromogens (pigments) to adhere to enamel
• Are often present in high concentrations in tea and coffee, making these drinks particularly high risk for staining
• Work together with acid to make enamel more porous and receptive to pigments

This combination explains why even light-coloured teas can stain teeth more than expected.

Prevention Tips for Everyday Life

Small daily habits can significantly reduce staining:

• Brush twice daily with fluoride toothpaste and clean between teeth (using floss or interdental brushes)
• Rinse or sip water after consuming foods or drinks with higher risk of staining
• Use a straw for cold coloured drinks
• Wait 30–60 minutes after acidic drinks before brushing to protect enamel
• Maintain regular hygiene appointments for professional plaque (bacteria) and stain removal

When to Seek Dental Advice

Contact your dentist if:

• One tooth suddenly changes colour
• Staining appears with pain, swelling, or sensitivity
• Discolouration progresses rapidly without a clear cause

Professional Treatment Options

Depending on the cause, your dentist may recommend:

• Hygiene cleaning (with or without Airflow option) to remove plaque (soft bacteria), calculus (hard bacteria) and extrinsic (external) staining
• Professional whitening for many extrinsic stains
• Veneers or restorative options for deep intrinsic staining

If you’d like personalised guidance on keeping your smile bright, an assessment with your Dentist can help identify the cause of staining and the most suitable treatment options available. You can book your dental appointments online, or via telephone/email where our administrative team would be happy to accommodate you.