"On my bottom front teeth, my gums were noticeably receding," she says. "This was when the sensitivity started, too. Whenever I drank anything very hot or cold, it hurt so much my eyes would water."
She assumed a cavity or abscess was to blame - even though she'd always prided herself on her perfect teeth.
The dentist's diagnosis came as a shock. "She blamed my electric toothbrush," says Natasha, from London. "I am a fastidious brusher and the dentist said it was likely I was over-brushing: using the brush too vigorously or brushing for longer than two minutes."
Enamel fillers, inserted into the depleted areas of her teeth, were her only option. It was the first time Natasha ever had to have a filling and she was understandably upset.
Natasha's story is not uncommon and marks a rise in the backlash against the use of electric toothbrushes, which have become more powerful over the years.
Some now provide up to 8,800 oscillations per minute. As a result, more and more dentists are advising a return to old-fashioned, manual brushing.
"I'm seeing an increasing number of patients with abrasion cavities and gum problems after using these powerful electric gadgets in the wrong way," says Dr Beeta Salek-Haddadi, a cosmetic dentist at Smile Solutions in London.
"People are brushing too hard and fast with them and it's causing damage."
Invented in Switzerland in 1954 by Dr Philippe-Guy Woog, the electric toothbrush was hailed as a great innovation.
Not only were they more efficient at removing plaque, dentists said they could also reduce incidents of gingivitis - an inflammation of the gums that can lead to tooth loss - by more than 17 per cent in three months.
• Early concerns
But not everyone was convinced. A study published in the Journal of Clinical Periodontology as far back as 2003 was already highlighting problems with electric brushes, claiming it was practically impossible for the average person to be able to tell if they were applying too much pressure.
Consequently, dentists started seeing patients with permanently damaged teeth enamel and gum recession.
If Martha Davis, 24, had known this, she would have reconsidered putting an electric toothbrush on her Christmas list in 2013.
For three months later, she was experiencing some alarming problems with her teeth. "My gums started to bleed as I was brushing and often I'd be spitting out bloody water into the sink," says the full-time mother-of-one. "My teeth would ache after brushing, too, and I could feel my fillings shaking as I used the brush.
"Eventually, they started to come loose, then in the space of one week all the fillings fell out one after the other. I was convinced I was brushing my teeth properly and brushing morning and night."
Martha went to see her dentist, who replaced the fillings and suggested she swap to a manual toothbrush for a while until things calmed down. But Martha decided to make the switch permanent.
"It was obvious there was a connection between the electric toothbrush and the damage in my mouth," she says. "The bleeding has stopped and my teeth don't ache any more. The electric toothbrush was obviously far too vigorous for me and I won't be going back."
Dr Seema Patel, clinical director at Elleven Dental in London, suggests it's not the electric toothbrushes that cause the damage, but the way people use them.
"Hardly anyone uses them correctly," he says. "You're meant to hold it next to the tooth surface, angling the brush towards the gums at a 45-degree angle.
"But most people use it like a manual toothbrush and will furiously move it across the teeth themselves, causing the enamel to thin out and the gum to be pushed down, making it more sensitive."
And once enamel has gone, it's gone for ever. "It can't repair or regrow," adds Dr Salek-Haddidi. "We have to use fillers or reposition the gum, which can be costly and uncomfortable."
• Practical changes
The way forward, she believes, is either re-learning the proper brushing technique with the help of a dental hygienist or returning to manual brushing using softer brushes, which bend on contact and can easily get into the grooves between tooth and gum.
"When you select your manual toothbrush, look for a one with very soft bristles," explains dental hygienist Edith Maurer Bussink.
"The most common mistake people make when brushing their teeth is to choose a medium or hard-bristled toothbrush, and then apply a large amount of pressure on to the teeth and gums, which leads to enamel erosion and receding gums.
"Also, people often brush their teeth right after eating - when there's a lot of acid in the mouth, which intensifies erosion."
According to Bussink, the best way to clean your teeth is to use as little pressure as possible, and to move your brush in small circular movements at a slight angle, half on the gum and half on the tooth.
"Cleaning the gum line is vital, as bacteria accumulates here and form deposits," she says.
Children, in particular, should never be given an electric toothbrush, warns Dr Salek-Haddidi.
"It would like be giving your child a calculator instead of letting them learn how to do sums from scratch," she says. "They'd never know how to brush their teeth properly if they didn't use a manual brush."
Natasha, meanwhile, has given up using her electric toothbrush for good.
"I love my smile and I don't want it to change or have any more problems with gums receding," she says. "I've gone back to a manual toothbrush and have a timer to make sure I don't go over the two minutes."
- Daily Mail