Your hygienist might extol the virtues of regular brushing, but even the most dedicated dental regime won’t do much about deep-set stains. Coffee, smoking, balsamic vinegar, red wine (not to mention white wine) take their toll on your teeth and undermine any well-intentioned grooming measures you may have implemented elsewhere on your face.

Enamel, the stuff that coats teeth, is made up of hydroxyapatite, a mineral composed of calcium and phosphate ions that are arranged in crystals. Staining occurs when molecules from last night’s dinner get stuck in the gaps of the aforementioned crystals and settle in for the foreseeable future.

Restoring lustre by way of a whitening treatment is now an affordable and relatively common solution. And while there is a variety of methods to choose from – pens, toothpastes, mouthwashes, strips and retainers – it’s hard to know where to begin. Having said that, the majority of whitening products all work on the same principle.

The most popular formulas contain either hydrogen peroxide or carbamide peroxide, both of which react with electrons in the stain molecule and disrupt the chromophore. Or, in layman’s terms, they break the chemical bonds that give your teeth that nasty yellowish colour. This is the exact chemical process your clothes undergo when you put them in the wash with a dash of bleach.

For a relatively minor cosmetic tweak, well-executed whitening can have a dramatic effect on a man’s appearance. If stained teeth are the dental equivalent of aged skin, then brighter gnashers can erase a decade in an instant (and, we hasten to add, without the flagrance of other anti-ageing procedures). Plus, you’ll be inclined to flash a smile more often, which can’t be too bad a repercussion.

So that you can go about the job in the safest and most effective fashion, we’ve compiled five pieces of whitening wisdom.

The efficacy of a home whitening kit has a great deal to do with the country in which it was manufactured. In 2012, the EU passed a stringent law that forbade the sale of over-the-counter products that contain anything over 0.1 per cent hydrogen peroxide, a concentration that is unlikely to do much to your smile. “They may as well have put it at 0 per cent,” says Dr Sanjay Haryana, head dentist at Metrodental in London.

He acknowledges that the directive was passed to protect both teeth and the professional whitening business. Higher concentrations of hydrogen peroxide can be hazardous when they’re not administered under the supervision of a dentist or dental therapist. So, if you reside in the United Kingdom and want to go up a shade or three, home whitening kits simply aren’t worth the time or money. You’ll need – for the time being at least – to visit your dentist for noticeable results.

Peruse the shelves in the US, however, and you’ll quickly find that the law is considerably more lax. It’s relatively easy to find whitening strips formulated with up to 10 per cent hydrogen peroxide. While it’s tempting to exceed this limit – hello, internet – we wouldn’t recommend it. The products that promise “instant” results invariably do so by bombarding the enamel with a high concentration of bleach that is likely to cause sensitivity, according to Dr Haryana. “I’m surprised that kind of concentration is available in a country where litigation is so common,” he says.

Whitening strips, such as those made by Crest, are usually the best method for home use because they have more contact time with enamel than, say, a toothpaste or mouthwash. Trays might seem like a more professional option, but the bleach routinely leaks out of one-size-fits-all moulds and onto the gums, which causes irritation. At the bottom of the list are whitening toothpastes, which are unlikely to remove anything other than light surface stains.

The best time to administer a home treatment is a couple of days after you’ve visited your hygienist, when surface stains and plaque have already been removed.

Mr Leone Giacosa, cosmetic dentist at Metrodental, routinely recommends a “whiter than white diet” when a patient undergoes a professional treatment. The white diet, you may have guessed, contradicts the kind of dietary advice you’d expect from a qualified nutritionist. One must stick to foods that are colourless and, by default, carb heavy (white rice, white bread, pasta, etc). “The pores of the enamel are open for a good 48 hours after whitening, so it’s easier for dark foods and drinks to stain teeth,” he says.

Even if you choose not to whiten your teeth, certain foods and drinks should be consumed with caution. According to the American Dental Association, coffee, tea and red wine are “major staining culprits”, as is tobacco. This is due to their intense colour pigments (chromogens), which attach to enamel. In short, if it can stain your white cotton shirt, it can stain your teeth. Equally bad are sticky foods such as fudge or barbecue sauce, which have a tendency to glue themselves to teeth.

Given how unlikely it is that you’ll start drinking your St Emilion through a straw, there are some simple measures you can take to offset staining from dark foods and drinks. The first tip is somewhat counterintuitive: don’t brush immediately after you’ve consumed anything dark because there’s a chance you’ll grind the stain deeper into the tooth. The same goes for acidic drinks, though the logic isn’t quite as straightforward. “Acid softens your enamel, and brushing too soon afterwards will only speed up tooth wear before the enamel has time to settle again,” says New York cosmetic dentist Dr Brian Kantor of Lowenberg, Lituchy & Kantor. “To speed up remineralisation, keep your mouth moist by drinking plenty of water so saliva can cleanse your mouth of these acids regularly.” But, given the choice between red wine and champagne, always go for bubbles.

DIY jobs are not advised. Yes, hydrogen peroxide with a little bicarbonate of soda may whiten your teeth, but nowhere near as well – or as evenly – as a professional treatment or strips. Plus, there is the added risk of making your gums sensitive with a homemade potion that has been measured out with shot glasses at 4.00am before a flight.

There was a short-lived trend for oil pulling, a non-toxic form of home whitening wherein swilling with coconut oil was reported to brighten choppers while preventing cavities and gingivitis. Unsurprisingly, the lack of clinical data for folk remedies means the jury’s still out on the efficacy of oil pulling. But, given what we know about stains and how they must be disrupted, it seems unlikely that the miraculous improvement some people report is anything more than a placebo effect that stems from having to swish grease in their mouth for 20 minutes while suffering jaw cramps.

“While it is possible that oil pulling may decrease the bacterial load in the mouth and help brighten your smile, there is not enough substantial evidence-based research to support the time-consuming process of oil pulling,” says Dr Jennifer Plotnick of Grand Street Dental in Brooklyn.

Last but not least, there are those cunning optical illusions that require no dental interaction whatsoever, such as getting a tan. When your brain tries to decipher the colour of something, it goes about the job of subtracting the lighting and background colours that surround the object in question. So, if your skin is a couple of shades darker than normal, bingo! Your teeth are instantly whiter. The risk, of course, is that, when you really run with this approach (and, perhaps, combine it with whitening strips), you end up looking like a contestant from Love Island.

The 30-minute whitening treatments offered at high-street dental surgeries might sound too good to be true. These are usually one-off power treatments that involve a high dosage of hydrogen peroxide (25 per cent and upwards) combined with laser treatment for about £200/$250.

The heat from the laser activates the bleaching product that has been painted onto your teeth, making it work considerably faster than it would if it were left to its own devices. This is why procedures such as Zoom whitening are often marketed as lunch-hour procedures. “The pitfalls with Zoom whitening (or other in-chair whitenings) are that the results are ephemeral, can cause sensitivity and will only lighten extrinsic stains as opposed to intrinsic stains,” says Dr Plotnick. She says the reason so many clinics offer in-chair laser whitening is because most customers want fast results. Seasoned dentists such as Dr Plotnick will usually combine in-chair whitening with a custom tray for home use (see below).

The process of laser whitening is not exactly comfortable. High concentrations of bleach require that the lips, gums and oral tissue are adequately protected. This means you’ll have to wear some rather fetching cheek retractors (like forceps for your mouth) and a rubber dam to protect your gums, neither of which is particularly comfortable if you have a normal gag reflex.

Compared to over-the-counter kits, professional whitening can seem like a big financial investment. Treatments start from about £300/$400, but, as with most things in life, you get what you pay for.

A cosmetic dentist will be able to find the exact shade of white that’s right for you. Mr Giacosa does this with his own version of a colour swatch, an intensely creepy stick that is lined with plastic teeth in varying shades of white. “Trying to match the white of your eyes gives you a natural and youthful smile,” he says, stick in hand. “Anything whiter than that can look a bit fake.”

Home whiteners, who rarely employ such discernment, can go overboard with bleaching products and end up with porcelain-white pearlies that can be seen from space. “When teeth are too white, they can start to take on a slightly translucent white and even appear to have more blue tones,” says Dr Plotnick. According to Dr Kantor, the Ross from Friends effect is rarely due to bleaching. “That result is from bad porcelain restorations,” he says.

Most dentists will offer two options: in-chair laser whitening (see above) or made-to-measure trays that are filled with a whitening solution. These are worn overnight for seven to 10 days and thus require an element of perseverance (it also means that when it’s time to top up, months or even years later, you can simply purchase some more bleaching gel from your dentist, which makes it more cost effective in the long run).

The made-to-measure tray method might sound painstaking and uncomfortable, but it’s far less aggressive than lasers. Anecdotal reports suggest that the results last longer, with less sensitivity. “Customised trays are the best system for tooth whitening as they allow the gel to work on only the crown of the tooth, reducing the chances of gum irritation,” says Mr Giacosa.

Carbamide peroxide is highly efficient at a dosage of 10 to 16 per cent. It is also more chemically stable than hydrogen peroxide, which grants it a far longer shelf life than run-of-the-mill whitening solutions (ideal if you plan on storing gels for impromptu top-ups). Both hydrogen peroxide and carbamide peroxide go about their job in the same way and produce the exact same results, but with a slight difference. “Hydrogen peroxide breaks down faster than carbamide peroxide, so it releases most of its whitening power within 30 to 60 minutes,” says Dr Kantor. “Carbamide peroxide, on the other hand, releases about 50 per cent of its whitening power in the first two hours and can remain active for up to six additional hours.” At worst, a professional treatment may irritate soft tissue or increase sensitivity but, in the hands of a professional, neither symptom is particularly painful or, indeed, permanent.