VOA慢速英语2014 机器人帮助牙医和患者

 

AS IT IS 2014-12-25 Robots Go To Work for Dentists and Patients

For years, robots have helped doctors perform operations with greater safety, speed and exactness than by using hand-controlled instruments. Now, one such machine reduces the time it takes to make dental crowns. This procedure can repair a damaged tooth in just about two hours.

Years ago, several long visits to the dentist were required to manufacture a dental crown. And between visits, the patient had to wear a temporary crown – a small, hat-like cover that encircles the tooth. During that period a technician prepares a permanent replacement¹.

Since the 1980s, robotic machines have greatly speeded up that procedure. Sitting in the dentist’s chair takes far less time than it once did.

Michael Silveus has a dental office in northern Virginia, near Washington, DC. He describes the time saved. 

“It’s about 12 minutes’ worth of chair time for the patient and the rest of the time, it’s work that’s taking place outside the patient’s mouth. “

Dr. Silveus and his assistant are preparing a patient’s tooth for a new crown. The drilling inside the patient’s mouth lasts about five minutes.

In the past, a plastic material was used to make an impression of the damaged tooth. But now, Dr. Silveus uses a video camera on a wand to inspect the tooth and the surrounding area. 

Next, a computer takes over the process. It designs the new crown and creates directions for a robotic milling machine. A small cube of porcelain² is placed between two drills, similar to the one the dentist uses. The porcelain is no larger than the tooth. The high-speed tools break off extra material from the cube, creating a perfectly³ shaped tooth crown.

To harden, the crown must be heated for about 10 minutes. During that process, its color is changed to the color of the patient’s other teeth.

Then, the dental crown is ready to be placed permanently⁴ in the patient’s mouth.

 “It feels amazing. The tooth feels like my tooth.”

Many people wearing crowns will say the newer procedure is a huge improvement over older methods. But Dr. Silveus says even this technology may someday become obsolete⁵.

“The other thing we look forward to is genetic⁶ engineering, and eventually cloning, so you can make the crown out of actually enamel⁷, just like the patient’s natural teeth are.”

For now, Dr. Silveus says his patients are happy to be able to get a new crown in just one visit.

Words in This Story

dentist – n. a person whose job is to care for people’s teeth

dental crown – adj. and n. a covering for a damaged or implanted tooth

impression – n. something (such as a design or footprint) made by pressing or stamping a surface

wand – n. an electronic device used to gather information

mill – v. to produce (something) by grinding, crushing or cutting

obsolete – adj. no longer used because something newer exists

1 replacement   

n.取代，替换，交换；替代品，代用品

参考例句：

• We are hard put to find a replacement for our assistant.我们很难找到一个人来代替我们的助手。
• They put all the students through the replacement examination.他们让所有的学生参加分班考试。

2 porcelain   

n.瓷；adj.瓷的，瓷制的

参考例句：

• These porcelain plates have rather original designs on them.这些瓷盘的花纹很别致。
• The porcelain vase is enveloped in cotton.瓷花瓶用棉花裹着。

3 perfectly   

adv.完美地，无可非议地，彻底地

参考例句：

• The witnesses were each perfectly certain of what they said.证人们个个对自己所说的话十分肯定。
• Everything that we're doing is all perfectly above board.我们做的每件事情都是光明正大的。

4 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。

5 obsolete   

adj.已废弃的，过时的

参考例句：

• These goods are obsolete and will not fetch much on the market.这些货品过时了，在市场上卖不了高价。
• They tried to hammer obsolete ideas into the young people's heads.他们竭力把陈旧思想灌输给青年。

6 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

7 enamel   

n.珐琅，搪瓷，瓷釉；(牙齿的)珐琅质

参考例句：

• I chipped the enamel on my front tooth when I fell over.我跌倒时门牙的珐琅质碰碎了。
• He collected coloured enamel bowls from Yugoslavia.他藏有来自南斯拉夫的彩色搪瓷碗。