VOA慢速英语：补牙或许不再疼痛

From VOA Learning English, this is the Health & Lifestyle report.

Many people fear a visit to the dentist. They are not so much afraid of the doctor, but of the dental equipment and treatments.

Well, fear no more!

A British company says it has developed technology that will end the need for mechanical cleaning of dental cavities. It also says the technology speeds up a natural process of tooth repair.

Having your teeth repaired can really hurt. So, people often do not go to the dentist as often as they should. New technology may change that forever.

For over a century, dentists have been repairing cavities the same way. They first remove the decayed, or bad, tooth tissue with an electric-powereddrill. Then, they fill the hole in the bone with a metallic or plastic substance.

If the cavity is not too deep, the experience can be unpleasant. However, if it is deep, near the nerve of the tooth, it can be very painful. The worst part is that the process of drilling and filling the cavity has to be repeated for the entire life of that tooth.

Rebecca Moazzez is a senior lecturer at King's College London. She says that this cycle lasts the rest of the tooth's life.

"You're really in that cycle of repair and replacement for the rest of the tooth's life."

Toothenamel is what we see on the outside of the tooth. The enamel of a damaged tooth can be replaced naturally. This process is called re-mineralization. But it is too slow to stop bacteria from building up in small, narrow areas of the enamel.

A British business called Reminova has developed a method for speeding-up this natural re-mineralization of early-stage cavities.

Jeff Wright is head of the company.

"We've just found a way to make that a much faster process. Driving healthy calcium and phosphate minerals into your enamel and, through a natural process, it will bind on and add to the enamel that's there."

The process begins with a cleaning of the cavity. This does not require power tools. The dentist covers the problem area with a mineral solution, and then uses an electrical current to harden this material. The electricity is too weak for the patient to feel. And the hardened mineral completely fills the cavity.

Researchers say this method could be especially useful for children. Sometimes children have bad experiences at the dentist. They fear the drilling and injections. Who wouldn't be afraid? Better experiences as a child might lead to more visits to the dentist as an adult.

Dr. Barry Quinn works as a consultant at King's College.

"If children have a better experience of going to the dentist, so they haven't had the necessarydrilling andinjections for routine fillings, then they'll be much more positive in later life and probably become much more regular patients."

Dentists say the new method is most efficient on early-stage cavities. The whole treatment lasts about as long as a normal drill-and-fill visit. Researchers say they believe the new method can be further developed for treating late-stage cavities.

And they are quick to note that regular cleaning with fluoride toothpaste helps prevent cavities in the first place.

And that's the Health & Lifestyle report.

I'm Anna Matteo.

George Putic reported this story for VOA. Anna Matteo adapted it for Learning English. George Grow was the editor.

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Words in This Story

dental cavity– n. a small hole formed in a tooth by decay

enamel – n. the very hard outer layer of a tooth

drill – n. a tool used for making holes in hard substances

injection– n. the act or process of forcing a liquid medicine or drug into someone or something by using a special needle

filling­– n. material that is used to fill something : example: a filling for a tooth

calcium– n. a substance that is found in most plants and animals and that is especially important in people for strong healthy teeth and bones

phosphate– n. chemistry : a salt or compound that has phosphorus in it and that is used especially in products (called fertilizers) that help plants grow

fluoride– n. a chemical that is sometimes added to drinking water and toothpaste to help keep teeth healthy