补牙时代结束.doc

补牙时代结束 From VOA Learning English, this is the Health amp; 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. For over a century, dentists have been repairing cavities the same way. They first remove the decayed, or bad, tooth tissue with an electric-powered drill. 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 Kings College London. She says that this cycle lasts the rest of the tooths life. Youre really in that cycle of repair and replacement for the rest of the tooths life. Tooth enamel 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. Weve 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 thats 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. An