A glass of water and soft toothbrush on a bathroom shelf

Quick answer

Tooth stains split into surface stains (coffee, tea, red wine, smoking; removed by a professional clean and polish), internal discolouration (age-related yellowing, tetracycline banding, fluorosis, enamel thinning; improved by professional whitening to varying degrees), and structural discolouration (a single dark tooth after nerve death, deep white or brown developmental spots, dark old fillings; needing internal bleaching, bonding, veneers or a new restoration). Matching the treatment to the stain type is the whole game, and it starts with a clean, because you can't judge tooth colour under a layer of tea.

Surface stains: the polishing kind

Coffee, tea, red wine, cola, curry and smoking build a film that ordinary brushing thins but doesn't remove. A professional clean and polish removes it entirely, and the shade change surprises people; a fair share of whitening enquiries end at the hygienist's chair, satisfied and cheaper. This is always step one, both because it may be sufficient and because whitening gel can't work through a stain layer.

Internal colour: the whitening kind

  • Age and genetics: enamel thins and the yellower dentine beneath shows through; this is the classic case professional whitening treats well
  • Tetracycline banding (grey-blue horizontal bands from childhood antibiotics): whitening helps partially and slowly; deep banding is honest veneer territory
  • Fluorosis and white spots: whitening lightens the background so spots blend better, and resin infiltration or microabrasion can treat the spots themselves; white marks left by braces-era plaque respond to the same tools

Structural cases: the restorative kind

  • One dark tooth in a bright smile usually had a nerve die quietly (an old knock, deep decay). External whitening barely touches it; internal bleaching (whitening from inside a root-treated tooth) or a veneer/crown are the real options
  • Old fillings that stained at their margins, or dark amalgam showing through a front tooth: replacement with modern materials fixes what no gel can
  • Deep developmental discolouration: bonding or veneers, matched after any whitening so the shades agree
The order of operations protects your wallet: clean first, judge the true shade, whiten if wanted, and only then match any bonding, veneers or crowns to the final colour. Restorations don't whiten, so doing this backwards means paying twice.