Sitting up in the dentist’s chair, still numb from the anaesthetic, I gazed into the mirror and felt sick with dismay. Instead of the healthy white teeth I’d walked in with, I now had a mouth full of tiny, mutilated stumps.

It felt, literally, like a nightmare. A horror movie. But not only was it real, it was all my own fault.

Seduced by images of celebrities with perfect Hollywood smiles, I’d decided the only way to achieve the teeth of my dreams was by getting veneers. Delicate porcelain covers would be cemented on to my natural teeth, filling gaps while widening and brightening my smile. What could go wrong? Quite a lot, as it turned out.

I’d always been unhappy with my teeth. In my childhood I had an overbite with prominent front teeth which stuck out so much I was called ‘Bugs Bunny’. This left me hugely self-conscious and anxious. I rarely smiled and often felt ugly.

In my early teens, I had hideous and painful NHS train track braces to straighten my teeth, but even after they came off my teeth still protruded a little. Unlike today, it wasn’t normal to be offered a retainer (to prevent teeth from reverting to their old position), and as I hit my 30s, I realised my front teeth were moving forward, creating a gap on each side.

Looking back, I can see the gaps were tiny, and my teeth were fine but, to me, traumatised by bullying, they seemed immense.

In photographs, they were all I could focus on. I became practised at smiling with my lips closed. It was obviously a kind of dental dysmorphia.

Then, in 1999, my now-husband proposed and the thought of wedding pictures with what I thought of as my ‘goofy teeth’ horrified me.

My current veneers have lasted well but at 61, writes Leah Hardy, I plan to be around for at least 20 years, and the chance of my veneers lasting this long is small

In my early teens, I had hideous and painful NHS train track braces to straighten my teeth, but even after they came off my teeth still protruded a little

I decided it was time to sort them out once and for all. I couldn’t face returning to wearing the giant metal braces, and transparent Invisalign braces weren’t yet available in the UK.

So, I visited a smart London clinic and explained I wanted straight teeth for the rest of my life. Without even the slightest attempt to dissuade me, and after a brief consultation, the dentist told me I’d need six veneers at a total cost of £4,000.

I was shocked I’d need so many veneers as only my two front teeth bothered me, but he insisted it was essential and I’d love the result.

Crucially, there wasn’t much talk about what the process involved. I certainly wasn’t told my teeth were fine, and there was no attempt to understand the psychological issues driving my decision. Instead, at my first appointment a few days later, the dentist cheerfully told me he would need to ‘prep’ my teeth to enable the veneers to stick.

This sounded non-invasive, so I wasn’t concerned when he numbed my mouth and started polishing away, even if it did seem to take quite a long time. But when I saw the ugly stumps I was left with, I wanted to cry.

Things didn’t improve when the dentist covered them with a strip of plastic teeth known as ‘temporaries’ to wear while my porcelain veneers were being made.

They looked like joke teeth from a Christmas cracker. All I’d been told was that my enamel would be ‘roughened’, not that my teeth would be reduced to tiny pegs.

For two weeks I consoled myself that soon I would have my dream smile. Yet, once I got the permanent veneers, I realised they were too short, too square, too thick, unrealistically opaque, and nowhere near as white as the teeth that had been replaced. I asked the dentist why, and he said I’d asked to look natural, so he’d matched the colour to my bottom teeth, which were more yellow than my previous front teeth – without telling me!

What’s more, there was a gap in the middle instead of gaps at the side of my front teeth. I should have complained, but I was too ashamed of my poor decision.

But the nightmare wasn’t only cosmetic. I wasn’t warned my new ‘lifetime’ teeth would last as little as a decade (the British Academy of Cosmetic Dentistry state that veneers typically last ten to 15 years).

I also had no idea my veneers could damage the remaining peg-like teeth so badly they could die, leaving me needing expensive implants or even dentures.

I’m far from the only one seduced by the prospect of a dazzling new smile.

Analysts say cosmetic dentistry is worth around £23billion globally, and is estimated to grow to £48billion by 2034. The UK market alone was valued at £283million last year and by 2029 is forecast to hit almost £376million.

Whether it’s Love Island-style ‘smile makeovers’ here or hopping on cheap flights to countries such as Turkey which offer cut-price treatment, Chris Dean, director at the Dental Law Partnership, believes many procedures are simply unnecessary.

‘The “new normal” for perfectly straight, brilliantly white teeth leads to many young people thinking there is something wrong with their teeth when they are perfectly fine and healthy.’

So, why are veneers so problematic? The hard surface of teeth is enamel, up to 2.5mm deep; underneath is bony dentine, and the core is a soft pulp containing roots, blood vessels and nerves. Before applying veneers, the dentist needs to remove between 0.5mm and 1mm of the enamel.

Finally, the teeth are ‘etched’ using an acid that roughens the surface, opening up tiny ‘pores’. Veneers are then attached with a dental cement that bonds into the pores and is hardened with a special light.

‘After this, even if you have good quality work and minimal destruction of the teeth, you can never take off your veneers and have your natural teeth,’ says Dr Jeremy Hill from Ware Centre of Dental Excellence in Hertfordshire. ‘You’re locked into a lifetime of replacement and maintenance.’

But why were my teeth reduced to rubble?

‘Veneers were invented to cover minor surface imperfections and small gaps,’ says Dr Hill. ‘They weren’t intended to straighten uneven teeth. To do that, teeth are filed down too far. When you take off so much enamel, the softer dentine is exposed. You can stick veneers to dentine, but the bond isn’t as strong.’

Dr Hill says veneers applied like this are unlikely to last. ‘They crack, break or fall off,’ he says.

‘The younger you start, the more likely you will get into trouble because you’ll need to replace them more often, putting your teeth at risk again.’

The pain is financial too, with veneers ranging from £600 to £2,000 per tooth.

By 2013 mine were still hanging on but cracked because of my grinding habit and yellow due to the ageing of the cement that glued them to my tooth stumps.

Fortunately I found a dentist I trusted to replace them. Professor Milvia Di Gioia, a highly qualified dental surgeon, advocates for natural teeth and was shocked I’d ever been given veneers.

Peering into my mouth, she described mine as looking ‘almost green because of yellowing and completely opaque’ because they were too thick to allow light to pass through, as natural teeth do.

She was even more horrified by the ruins of my teeth once my old veneers were removed. I’ve since learned thick veneers are easier for inexperienced dentists to work with but mean, as in my case, much more tooth is destroyed.

Professor Di Gioia ordered bespoke, hand-crafted veneers from Italy that would be more translucent, look more natural and rounded, and better suit my face. They were designed to enclose my teeth so they would be more likely to stay in place. None of this was cheap. Each tiny veneer costs more than £1,000.

Even though I was delighted with the result, I still feel sad I ever got veneers in the first place.

My current veneers have lasted well but at 61, I plan to be around for at least 20 years, and the chance of my veneers lasting this long is small. Spending £12,000 to replace them in my old age makes me feel sick.

I urge people not to follow my example and think about why they really want this done, and to realise that veneers are even more irrevocable than tattoos. If I could turn back time, I’d leave well alone.