Up to 100,000 people undergo some form of teeth-whitening treatment each year, 10 times more than five years ago. It's hardly surprising as whitening can make a dramatic difference. But how do you choose between low-cost toothpaste and other over-the-counter products at one end, and high-cost dental procedures?
Use whitening toothpaste to get rid of everyday stains. Ask your dentist about home bleaching kits such as Optident (around £700). He or she will prepare a rubber mouth tray you fill with bleaching gel and wear for several hours each day over several weeks. "It's the best-researched method," says Professor Andrew Eder, consultant in restorative dentistry at the Eastman Dental Hospital and director of the London Tooth Wear Centre.
Try DIY bleaching using baking soda or hydrogen peroxide, or by rubbing salt in your teeth, as recommended by users of several websites popular with teenagers. "These are abrasives that with repeated use will wear away the white enamel and eventually leave the tooth browner and with increased sensitivity," Professor Eder says. And don't be talked into expensive laser treatment – "there's little evidence to support its use," he says.
Absolutely everyone going on a cosmetic-style reality television show gets veneers, the wafer-thin laminates made from po rcelain, ceramic or composite bonding material that are cemented to the front of a tooth like a false fingernail on a nail.
Veneers can spectacularly improve discoloured, chipped or broken teeth. Yet they are dangerous in unskilled hands, particularly when dentists offer to provide a whole mouthful of veneers at a suspiciously low price.
Many widely promoted procedures require dentists to destroy "vast amounts of sound, hard tooth tissue", even sometimes "drilling a sound tooth down to a stump", according to Dr Martin Kelleher, a consultant in restorative dentistry at Guy's, King's & St Thomas' Dental Institute. Nearly one in five teeth becomes "dead" within five years of being prepared for a veneer, according to recent studies – making them far more likely to become infected and cause permanent problems.
"Many dentists offer veneers after a one-day hotel course, which I believe is wrong," says Shaun Smith, senior partner at The Dental Surgery in the City of London.
It's little comfort for patients with continuing dental problems that, according to Dr Kelleher, there's been a "huge increase in settlements in cases involving aesthetic treatment when this has not led to patient satisfaction".
Ask your dentist if he or she would recommend the veneer project for his or her own daughter. This "daughter test" should be an essential element of "clinical decision-making in this difficult and complex area", says Dr Kelleher, writing in the journal Dental Update. "At its simplest, it asks the question: 'Knowing what I know about what this procedure would involve to the teeth in the long term, would I carry out the procedure on my own daughter?'" It is curious, he says, how often the answer is no.
Be prepared to pay for the best
Take your time to have a veneer or crown. Find a dentist who is not going to rush you and who is ready to try non-invasive methods such as white fillings, tooth whitening or braces.
Choose a veneer that is whiter than the whites of your eyes. "We've got used to whiter teeth over the last 10 years and our smiles have got wider," Shaun Smith says. "But you still don't want to be too white."
The heavy metal brace that once characterised the early teenage look is now increasingly rare. But braces are used far more widely today than ever before: they are simply invisible. They are also far safer than invasive procedures. The downside is that the best braces have been patented by US companies which remain the sole manufacturers. As a result, the cost of modern braces tends to be high – around £3,000 on average, though costs vary between practices.
* The Inman Aligner uses nickel titanium springs to provide a constant gentle pressure that squeezes teeth together by pushing and pulling them into alignment. Dentists recommend it for frontal overcrowding or for teeth that protrude or need rotating.
* Invisalign is a series of removable, clear aligners that straighten teeth. Patients graduate to a new set of aligners every two or three weeks.
* Six Month Smiles straightens the most prominent teeth and so can't be used on back teeth or to change the bite. Tooth-coloured brackets and invisible wires cause tooth movement to occur two to three times faster than standard methods, it is claimed.
This occurs as a result of severe grinding or clenching of the jaw, largely caused by stress – though ecstasy use is a also a risk factor. "Working in the City makes this a common problem in my practice," Shaun Smith says. "People clench their teeth so hard they crack healthy teeth right down to the root. It can be a huge problem, causing facial pain and headaches as well as dental damage."
Discuss the need for stress management with your dentist or GP. Try a nightguard to prevent grinding, and consider dental treatment, such as a veneer, crown, or cap, to eliminate the crack. A root filling may be needed in extreme cases.
Another modern problem caused mainly by acid in fizzy drinks or from acid reflux (a frequent effect of hiatus hernias), or in alcohol, fruit and salad vegetables. Mild cases cause blotches and discoloration. More severe erosion slowly dissolves teeth, making them shorter or misshapen. One in two children has tooth erosion, according to the most recent Child Dental Survey. In adults, it can cause the lips almost to disappear. Treatment can be "like having a face lift or lip fillers", Professor Eder says.
Lifestyle changes are essential. Tooth-coloured fillings may help. Veneers, or in extreme cases crowns, may be required.
Top tips to stop tooth erosion
* Don't swish fizzy drinks around your mouth – use a wide straw whenever possible.
* Don't sip acidic drinks over a long period. The acid stays in your mouth for an average of 45 minutes and sipping on a can of cola over several hours keeps your teeth in an acidic bath.
* Don't clean your teeth within 45 minutes of consuming anything acidic or you'll push the acid into the enamel.
Your lips, cheeks and lower jaw change as you grow older, causing your teeth to become more crowded or to move forward, especially in the lower jaw. "These soft tissue changes can occur because of normal ageing or teeth that have been straightened in early life can relapse at a later stage," says Dr Neera Maini of the Aqua Dental Spa in west London.
A brace often works best. Dr Maini advises following it with a "retainer", an invisible wire device fixed to the back of the teeth to keep the changes in place. Treatment may involve extracting a tooth. Don't be rushed into this – if it is necessary, it requires careful planning.