Examination and reassurance
Under magnification and transillumination we confirm the lines are confined to enamel, test the teeth for any tenderness, and record their pattern so it can be compared at future visits.
About this treatmentDental condition · Wimpole Street, Marylebone
Craze lines: the fine cracks in front teeth that usually mean nothing
Catch your front teeth in raking light and you may notice hairline vertical marks in the enamel, sometimes dozens of them. These are craze lines, and almost every adult has some. They sit entirely within the enamel, which has no nerve, so they cause no pain and do not weaken the tooth in any meaningful way. Think of them as the enamel equivalent of fine lines on skin: a record of years of chewing, hot and cold, and the odd knock. The reasons to have them looked at are cosmetic, when staining makes them visible in ordinary light, or diagnostic, when a line might actually be a deeper crack. At Wimpole Street we can tell the difference in a few minutes.
Recognising it
How it usually feels
Fine vertical lines visible only in certain light
Typically on the upper front teeth and running from edge towards gum.
No sensitivity or pain whatsoever
Enamel-only lines cannot stimulate the nerve.
Lines that have picked up brown or grey colour
Tea, coffee, wine and tobacco stain the tiny gap over the years.
More lines on the teeth you grind or clench with
Sustained load accelerates their formation.
Lines that look the same year after year
Stability is reassuring; change is what prompts closer inspection.
A line that catches an explorer or feels like a step
That is not a craze line and warrants proper crack testing.
Behind the symptoms
What's going on
- 01
Ordinary function over decades
Enamel is the hardest tissue in the body but it is also brittle. Millions of chewing cycles create microscopic stress fractures in the surface that gradually become visible. Their number climbs steadily with age, and by middle age they are nearly universal.
- 02
Thermal cycling
Hot coffee followed by iced water makes enamel expand and contract within seconds. Repeated over years, that stress shows up as surface crazing, much as it does in glazed pottery.
- 03
Grinding and clenching
Bruxism loads the front teeth in ways they were not designed for, particularly during side-to-side grinding. People who grind often have more and darker craze lines, and it is worth checking whether they also have worn edges or jaw ache.
- 04
Minor knocks
A glass, a cutlery clash or a childhood fall can leave a craze line without any other consequence. The line may only become noticeable years later once it stains.
- 05
Whitening and dehydration
Whitening gels temporarily dry the enamel and can make existing lines look more prominent for a few days. They are not creating new cracks, and the appearance settles as the tooth rehydrates.
- 06
Confusion with genuine cracks
Occasionally what looks like a craze line is a fracture extending into dentine. Clues include a single, wider, darker line, pain on biting, or a line that continues below the gum. These are assessed as cracked teeth rather than craze lines.
Before your appointment
What you can do today
- Nothing needs doing for the lines themselves; keep brushing and flossing as normal.
- If staining bothers you, reducing tea, coffee, red wine and tobacco slows further discolouration, and a hygiene polish lifts surface stain.
- Avoid habits that stress front teeth: opening packets, biting nails, chewing ice or pen tops.
- If you know you grind, wear a night guard to protect the edges of your front teeth.
- Take a photograph in good light so you can compare over time; genuine change is what matters.
These are holding measures, not a substitute for an examination. Use any pain relief exactly as directed on the pack and check with a pharmacist if you take other medicines.
In the chair
How we treat it at Wimpole Street
Hygiene polish
Surface stain along craze lines often responds to professional polishing or Airflow cleaning, making them far less visible without touching the enamel.
About this treatmentTeeth whitening
Brightening the overall tooth shade reduces the contrast between the line and the surrounding enamel, which is usually what makes stained lines noticeable.
About this treatmentComposite bonding
For lines that remain conspicuous, a very thin layer of composite over the front surface masks them. Enamel preparation is minimal, and the result can be refreshed in future.
About this treatmentPorcelain veneers
Where craze lines are one of several concerns on the front teeth, such as wear, chips or discolouration, veneers address them all at once with excellent long-term colour stability.
About this treatmentNight guard
If grinding is driving the pattern, a custom guard protects the enamel and any cosmetic work from further stress.
About this treatmentFees
Costs to expect
Assessing craze lines is part of a routine examination, expected to be £95 at Wimpole Street, and in the great majority of cases no further treatment is needed or advised. A hygiene visit to remove surface stain is from £89.
If you choose to address the appearance, whitening is indicative from £395, composite bonding from £395 per tooth, and porcelain veneers from £1,095 per tooth. A night guard for grinders is around £395. We will always tell you if we think treatment is unnecessary.
Figures are indicative prices for Wimpole Street and are confirmed in a written plan once a dentist has examined you. Fees match our South Kensington and St Paul's clinics.
Don't wait if
When to see a dentist
- A line is accompanied by a sharp pain when biting or releasing.
- The tooth has become sensitive to hot, cold or sweet.
- One line looks distinctly wider, darker or longer than the others, or seems to be changing.
- A line appeared after a knock to the face.
- You can feel a step or catch along the line with your fingernail.
- The appearance is affecting your confidence and you would like to discuss options.
FAQ
Common questions
No. They are superficial marks within the enamel and do not reduce the strength of the tooth in any measurable way. They are found in perfectly healthy mouths and are more a marker of age and use than of any problem.
Typically they stay where they are. A craze line does not have the depth to propagate the way a fracture into dentine does. Teeth under heavy grinding forces can develop genuine cracks, but that is a separate process rather than a craze line growing.
Whitening gel dehydrates the enamel for a short period, which makes it more opaque and throws surface texture, including craze lines, into sharper relief. This fades over a few days as the enamel rehydrates and is not a sign of damage.
Often it reduces it considerably, since the peroxide penetrates the enamel and lightens the pigment trapped in the line as well as the surrounding tooth. Very dark, long-standing lines may remain faintly visible, in which case bonding is the next step.
There is no protective reason to do so. Bonding over craze lines is purely cosmetic, and we would only suggest it if the appearance troubles you. Sealing lines that are not causing any problem adds maintenance without adding benefit.
Marylebone, W1
Wimpole Street opens 1 October 2026
Leave your details and we will be in touch when the Marylebone diary opens. If the problem cannot wait, the same clinicians are already seeing patients in South Kensington and at St Paul's.
Opening 1 October 2026
Wimpole Street is not yet seeing patients. Until then, please book or call our South Kensington clinic on 020 7183 2362 or our St Paul's clinic on 020 7183 3709. Questions about the new clinic: wimpolestreet@md.co.uk.
Until we open
Need an appointment before 1 October 2026?
The same clinical team already works from two other Medical & Dental clinics. Book at either one now and, if you prefer, move your ongoing care to Wimpole Street once the doors open.
South Kensington
- 20 Old Brompton Road, London SW7 3DL
- Open seven days a week
- 020 7183 2362
St Paul's, City of London
- 5 Ave Maria Lane, London EC4M 7AQ
- Open Monday to Friday
- 020 7183 3709
