When you think about the ingredients in toothpaste, what comes to mind? You might think of fluoride, a mineral that helps strengthen your teeth and prevent cavities. You might think about mint or other flavourings. But what about hydroxyapatite?
If you're thinking "hydroxy-what?" you're not alone. Hydroxyapatite toothpaste isn't just a mouthful to say — it's also not as well-known as fluoride or other toothpaste ingredients. Although you won't find it in every toothpaste on the shelves, hydroxyapatite has a role to play in helping to keep your teeth strong and healthy.
What Is Hydroxyapatite?
On purely a chemical level, hydroxyapatite is a naturally occurring form of the mineral calcium apatite, also known as calcium phosphate. The majority of the enamel and dentin in your teeth is made from a form of hydroxyapatite. According to National Oral Health Programme of the IDA, eating starchy foods such as crackers, bread, cookies and candy causes the bacteria in your mouth feed on it, they then produce acids, which attack your teeth for up to 20 minutes or more. Also, foods that stick to your teeth or are slow to dissolve give the acids more time to work on destroying your tooth enamel. The presence of hydroxyapatite in your tooth enamel is what makes it the hardest substance in your body.
Although tooth enamel is a strong and durable substance, it's not invulnerable. The Open Dentistry Journal reports that acids from food and drinks as well as dental plaque can partly dissolve enamel. To keep your teeth healthy and free from cavities and enamel erosion, the enamel needs to be constantly built back up, or remineralised. Your saliva can help in the remineralisation process, as can toothbrushing with a fluoride toothpaste. Toothpastes that contain calcium phosphate or hydroxyapatite can also help remineralise and restore enamel.
How Hydroxyapatite Helps Rebuild Tooth Enamel
Toothpastes that contain hydroxyapatite can help remineralize the enamel, reducing the risk of cavities and erosion. Although you might not easily find a toothpaste that contains hydroxyapatite or calcium phosphate on the shelf at a drugstore, there have been multiple studies that examine the effect the ingredient has on the tooth enamel.
One study, published in the Journal of Dental Research, Dental Clinics, Dental Prospects, looked at the effect hydroxyapatite toothpaste had on a group of 80 extracted teeth. Forty teeth were brushed with an ordinary fluoride toothpaste and 40 were brushed with a toothpaste containing both fluoride and nano-hydroxyapatite (nano- means the particles of hydroxyapatite were extremely small). All the teeth were demineralised using an acid solution, then brushed twice daily with one of the two toothpastes for 15 days. The teeth that were brushed with the nano-hydroxyapatite-containing toothpaste were considerably harder (remineralised) at the end of the study compared to those brushed with toothpaste containing only fluoride.
Another study published in the Korean Journal of Materials Research examined the effect that toothpaste containing a variety of concentrations of hydroxyapatite could have on teeth. Researchers created multiple kinds of toothpaste with concentrations of hydroxyapatite ranging from 0 to 15 percent. The toothpaste samples were then applied to extracted human teeth that had been drilled to create artificial cavities. After seven days of cycling between a demineralising acid solution, a remineralising solution and brushing treatment, the teeth brushed with the toothpaste that contained the highest concentration of hydroxyapatite showed the most improvement in the strength of the enamel (remineralised) and the depth of the cavities was lessened.
How Else Does Hydroxyapatite Toothpaste Help Your Teeth?
The Open Dentistry Journal reviewed other studies that examined the effect hydroxyapatite has on teeth. It noted that toothpastes that contain the ingredient helped to reduce plaque, minimise bleeding gums and reduce oral bacteria.
Should you look for a toothpaste that contains hydroxyapatite? Before you start scouring the store shelves, it's a good idea to speak with your dentist about your oral health concerns. If you have a history of sensitive teeth or weak enamel, a remineralising toothpaste might be a good option for you. Your dentist can recommend the best toothpaste for you based on your current needs and oral health history.