[by:www.21voa.com]
[00:00.00]更多听力请访问21VOA.COM
[00:00.16]From VOA Learning English, 
[00:02.64]this is the Health & Lifestyle report.
[00:05.96]Many people fear a visit to the dentist. 
[00:09.96]They are not so much afraid of the doctor, 
[00:13.08]but of the dental equipment and treatments.  
[00:18.90]Well, fear no more!  
[00:21.04]A British company says it has developed technology 
[00:25.88]that will end the need for mechanical cleaning of dental cavities.  
[00:31.24]It also says the technology speeds up a natural process of tooth repair.   
[00:38.28]For over a century, dentists have been repairing cavities the same way.  
[00:43.82]They first remove the decayed, or bad, 
[00:47.80]tooth tissue with an electric-powered drill. 
[00:51.56]Then, they fill the hole in the bone with a metallic or plastic substance.   
[01:00.00]If the cavity is not too deep, 
[01:02.68]the experience can be unpleasant. 
[01:05.72]However, if it is deep, near the nerve of the tooth, 
[01:09.92]it can be very painful. 
[01:12.60]The worst part is that the process of drilling and filling the cavity 
[01:17.88]has to be repeated for the entire life of that tooth.  
[01:22.96]Rebecca Moazzez is a senior lecturer at King's College London.  
[01:29.00]She says that this cycle lasts the rest of the tooth's life.  
[01:34.48]"You're really in that cycle of repair and replacement for the rest of the tooth's life." 
[01:39.12]Tooth enamel is what we see on the outside of the tooth. 
[01:44.12]The enamel of a damaged tooth can be replaced naturally.  
[01:49.00]This process is called re-mineralization. 
[01:53.40]But it is too slow to stop bacteria 
[01:56.72]from building up in small, narrow areas of the enamel.
[02:02.12]A British business called Reminova has developed a method 
[02:06.76]for speeding-up this natural re-mineralization of early-stage cavities.  
[02:13.48]Jeff Wright is head of the company.  
[02:16.08]"We've just found a way to make that a much faster process. 
[02:21.00]Driving healthy calcium and phosphate minerals into your enamel 
[02:25.70]and, through a natural process, it will bind on and add to the enamel that's there." 
[02:31.00]The process begins with a cleaning of the cavity. 
[02:34.76]This does not require power tools. 
[02:37.88]The dentist covers the problem area with a mineral solution, 
[02:42.72]and then uses an electrical current to harden this material.  
[02:48.40]The electricity is too weak for the patient to feel.  
[02:52.76]And the hardened mineral completely fills the cavity.
[02:56.64]Researchers say this method could be especially useful for children. 
[03:02.28]Sometimes children have bad experiences at the dentist. 
[03:06.76]They fear the drilling and injections.  
[03:10.20]Who wouldn't be afraid? 
[03:12.32]Better experiences as a child might lead to more visits to the dentist as an adult.   
[03:19.37]Dr. Barry Quinn works as a consultant at King's College.
[03:23.92]"If children have a better experience of going to the dentist, 
[03:26.62]so they haven't had the necessary drilling and injections for routine fillings, 
[03:31.54]then they'll be much more positive in later life 
[03:34.08]and probably become much more regular patients."
[03:36.48]Dentists say the new method is most efficient on early-stage cavities. 
[03:41.72]The whole treatment lasts about as long as a normal drill-and-fill visit.  
[03:47.64]Researchers say they believe 
[03:49.80]the new method can be further developed for treating late-stage cavities. 
[03:55.80]And they are quick to note 
[03:57.64]that regular cleaning with fluoride toothpaste 
[04:01.16]helps prevent cavities in the first place. 
[04:04.52]And that's the Health & Lifestyle report.
[04:07.08]I'm Anna Matteo.
[04:08.36]更多听力请访问21VOA.COM