Top dentists have revealed how trendy fads are wreaking havoc with people's teeth.
Despite the likes of Gisele Bündchen and the Hemsley sisters swearing by starting every morning with a refreshing glass of hot water and lemon, Dr Ben Atkins, a dentist based in Manchester and Trustee of the Oral Health Foundation, warns the drink effectively dissolves teeth and could even make them darker.
While critics link fluoride to everything from dementia to diabetes, experts argue numerous studies show the mineral does not harm people's health, with free-form varieties missing out on 'the main protective ingredient', the Daily Mail reports.
Dr Atkins also describes the ancient Ayurvedic practice of oil pulling, which involves swishing coconut oil around the mouth, as a 'waste of time', with Dr Rhona Eskander, Best Young Dentist Winner 2016, adding it will not give you a Hollywood smile.
In terms of brushing your teeth with charcoal or apple cider vinegar, both Dr Atkins and Dr Eskander add the 'natural remedies' could do more harm than good as while their acidic, abrasive consistencies may remove surface stains, they could also permanently damage enamel.
Here, Dr Atkins and Dr Eskander exclusively reveal how to dodge dental fads and best look after your teeth.
Health authorities in the US call water fluoridation "one of the top 10 public health achievements of the 20th century".
Yet critics claim the mineral disrupts hormones, leading to chronic health problems including bone disorders, dementia and diabetes, resulting in a recent surge in fluoride-free alternatives.
Dr Eskander told MailOnline: "Fluoride is the main protective ingredient in toothpaste. It prevents decay and counteracts the effects of decay forming, particularly if you eat a lot of sweets or fruit."
Fluoride toothpastes work by depositing the mineral in enamel, which is broken down by acidic foods. This makes teeth more resistant to such foods and prevents decay.
Yet, critics add that fluoride toothpaste packaging often warns people not to swallow the product and just to use a pea-sized amount due to the thin mucus membranes in the mouth allowing ingredients to be absorbed into the body.
According to Dr Eskander: "You would need to consume a huge amount to have a toxic effect."
While fluoride can cause yellow streaks to form in children's teeth, Dr Atkins adds this is not harmful and usually only obvious to dentists.
He told MailOnline: "There have been countless reports and peer-reviewed research into fluoride and the scientific conclusion is that fluoride toothpaste is of great benefit to our oral and cause no harmful side effects to general health.
"There are toothpastes which are fluoride-free. Some may have antibacterial agents, freshen breath and if they are abrasive, they could remove surface staining.
"Unfortunately what a fluoride-free toothpaste won't do is protect your teeth from tooth decay."
Hot water and lemon drink
Hot water and lemon is said to be rich in vitamin C, which boosts the immune system, as well as encouraging the production of bile to aid digestion.
Yet, experts warn guzzling the trendy beverage could cause serious dental damage.
Dr Atkins said: "Lemon in hot water may be a good way of getting some vitamin C but it can play havoc with your teeth.
"I recently had a patient who never had any serious oral health problems. They visited me regularly for check-ups and I sent them away with a clean bill of health every time.
"Then during one visit she complained that she was having constant and very painful sensitivity with hot and cold things.
"I quizzed her to see if she has changed anything about her routine and diet recently and that is when all was revealed. She said that she recently changed her morning routine to include a glass of hot water with lemon juice in it as she read that it was good for her.
"While it may be good for other parts of our health, lemon juice hugely dangerous to our mouth when drank in this way. Sipping it all day, every day means the acid constantly attacks our teeth."
Lemon is extremely acidic, which weakens the enamel in teeth and effectively dissolves them, explains Dr Eskander.
This can even lead to discolouration as the harder matter below the enamel starts to shine through, which also causes sensitivity and pain, according to Dr Atkins.
If people still choose to drink hot water and lemon, Dr Eskander recommends they do so through a straw to reduce the teeth's surfaces being hit by the liquid. Chewing sugar-free gum afterwards is also a good idea as it stimulates saliva, which neutralises acids, she adds.
Dr Eskander also advises people to never brush their teeth after drinking hot water and lemon as this remove enamel while it is soft. People should instead brush their teeth before breakfast to create a protective fluoride layer against acidic foods.
The ancient Ayurvedic practice of oil pulling is said to date back more than 3,000 years and involves swishing a tablespoon of coconut or sesame oil around the mouth for up to 20 minutes before spitting it out.
Advocates claim the oils' 'antibiotic and antiviral properties' brighten and clean teeth.
Yet, Dr Atkins argues: "Coconut oil pulling has no scientific proof of being beneficial to oral health in any way. It is ineffective and ultimately, a waste of time."
Dr Eskander adds oil is a lubricant and can therefore temporarily dislodge food particles and surface stains, but will not penetrate teeth to make them whiter.
She said: "It does no harm but won't create a Hollywood smile."
Only whitening with peroxide penetrates teeth and breaks down discolouring.
Dr Eskander adds this should only be done by dental professionals who, unlike DIY kits, make bespoke trays for the mouth and ensure peroxide does not harm the gums and cause blistering.
Despite the recent surge in charcoal toothpastes on the market, Dr Atkins warns they could do more harm than good.
He said: "There is inadequate data to prove the safety and efficacy claims of charcoal and charcoal-based oral health products. The claims made by many of these products in terms of tooth whitening are unverified".
Advocates argue charcoal's porous structure gives it detoxifying properties, with hospitals frequently using it to treat different kinds of poisoning and overdoses.
Yet, although charcoal toothpastes may remove superficial stains due to their abrasive consistency, Dr Atkins says this may permanently damage enamel.
He added: "Most importantly, many charcoal toothpastes on the market do not contain enough fluoride to adequately protect us from tooth decay, even when used for two minutes twice a day."
Apple cider vinegar
Apple cider vinegar is praised for aiding digestion, helping with weight loss and making hair shinier, with some even brushing their teeth with this highly-acidic substance.
Yet, while the vinegar's abrasiveness may help to remove plaque and stains caused by red wine, coffee and smoking, Dr Eskander warns it could also severely damage enamel and even make teeth yellower.
She said: "Enamel damage is irreversible.
"The layer beneath, known as the dentin, becomes more visible.
"Dentin has a natural yellow tinge, meaning that you're likely to be left with teeth that look more yellow or stained than they did to begin with."