If your teeth are highly sensitive to hot and/or cold liquids and foods, it's likely because their protective outer layer of enamel is worn away. While there are treatments for the problem, they tend not be very long-lasting. There could be new hope, however, thanks partially to a green tea extract.
When a tooth's enamel gets worn off, the dentin tissue underneath is exposed. Hot and cold foods and liquids can then travel down tubules (microscopic hollow tubes) in that dentin, contacting nerve endings in the tooth – that's where the pain comes from. Additionally, teeth with exposed dentin are more prone to cavities than healthy teeth.
Ordinarily, a mineral known as nanohydroxyapatite is used to plug those tubules, temporarily relieving the discomfort. Unfortunately, however, the mineral is quickly worn away by regular brushing, tooth-grinding, and acid produced by cavity-causing bacteria.
Led by Cui Huang, scientists from China's Wuhan University have combined nanohydroxyapatite and a green tea polyphenol (a type of micronutrient) called epigallocatechin-3-gallate, or EGCG – the latter has previously been shown to fight Streptococcus mutans bacteria, which forms biofilms that cause cavities.
The mixture was encapsulated in silica nanoparticles, then applied to extracted wisdom teeth. Not only did the particles effectively plug exposed dentin tubules, but they also released EGCG for at least 96 hours, stood up well to brushing and tooth erosion, and prevented the formation of biofilms.
It is now thought that the technology could be "a good candidate for combating tooth sensitivity and cavities," perhaps in the form of a toothpaste additive.
A paper on the research was recently published in the journal ACS Applied Materials & Interfaces.
Source: American Chemical Society