Researchers Duplicating Human Mouth in Laboratory
Feb. 14, 1988
MINNEAPOLIS (AP) _ It looks like an ordinary set of false teeth, but it's mounted in something that looks like a machine-shop drill press.
''It doesn't look like an artificial mouth, but it works like one,'' said Dr. William Douglas, who directs the Artificial Resynthesis Technology study at the University of Minnesota.
Scientists are using a pair of the bulky machines, the only ones of their kind, to test dental products and conduct other kinds of research.
Douglas and his colleagues can duplicate the rigors of a year of chewing in a single day. That, he says, offers hope for vast improvement in the quality of dental fillings and crowns and in scientists' ability to understand the forces of chewing and digestion.
Without the new technology, Douglas explains, manufacturers must test and prove the durability of their wares in the mouths of real subjects. Years of grinding and chomping must go by before researchers can judge a product's merit.
''If you put this together, you have an investigative tool,'' said Douglas, 50, who left a research post in Wales to do research at the university.
''If you have an obedient artificial mouth which is believable, you have something to enable you to approach many tough problems that otherwise would be very difficult to do.''
The mouth began taking shape when Douglas joined the dental research staff at Minnesota in 1978. His endowed chair is partly funded by 3M Co., based in the St. Paul suburb of Maplewood. 3M is a leading manufacturer of fillings, crowns and other dental products.
Douglas soon learned of a company, MTS Systems Corp., in suburban Eden Prairie that builds test equipment with the precision and sophistication he needed to replicate mouth dynamics in the laboratory.
Along with colleagues Ralph DeLong and R.L. Sakaguchi, Douglas adapted MTS equipment to build the mechanical mouths.
The next step was artificial saliva. A researcher at State University of New York at Buffalo has learned how to make it, and he sends Douglas and company quantities to use with the mouth. Jets shoot the saliva and other lubricants between test teeth the way ducts do in real life.
Along with the mouth, the dental researchers have developed computer imaging technology that maps precisely where and how teeth wear out.
''It's a very painstaking procedure right now, where you're marking on teeth ... and measuring them,'' said Walter Poxon, international professional services manager for 3M. ''This computer imaging is the state of the art in dental materials research. It really does give you an accurate picture of what's happening.''
Douglas has other, more ambitious dreams for his mouth. Now, it chews only in the sense that it simulates the wear-and-tear of chewing. He wants it to masticate fully - to grind, break down and even swallow food.
The next step: development of artificial tongues and cheeks. Douglas is poring over scientific papers for background while he prepares applications for National Institute of Health grants to finance more work in that direction.
''I want to figure out how this thing can give a good simulation of what happens in the human mouth. For that you need a tongue and cheek mechanism,'' Douglas said. ''It's very tough. It's a very difficult thing to do.''
Douglas sees a complete artificial mouth as a research tool for food- product development, a field in which tenderness, texture and ''mouth feel'' possess tremendous importance. The artificial mouth would be able to quantify precisely the oral effort Product X would demand of the consumer.
''You have an instrument that can figure out just how much mastication has to go into that beef,'' he said.