Because dental instruments are constantly exposed to blood and saliva, dentists have a strict responsibility to sterilize them. In some cases this is extremely difficult, and in others it isn't always done properly. For example, the pressurized steam heat that is now most often used for sterilization can melt plastics or corrode metal on some instruments. And moisture can shorten the life of metal instruments. That raises costs and prompts some dentists to rely on less effective means of sterilization, says Michael D. Rohrer, associatedean of the University of Oklahoma's College of Dentistry.
Rohrer and his colleagues have developed a way to sterilize instruments using microwaves. The researchers devised a patented method of rotating and tumbling instruments within a microwave field. That avoids a serious problem--the "cold spots" caused by waves canceling each other out. The technique ensures that all the instruments are completely sterile, Rohrer says. The university is now working on ways to commercialize the invention.