A nifty gadget promises to restore a healthy new smile, from an imperfect or damaged one. It’s an ultrasound 1) ___ that fits neatly inside a person’s mouth like a brace and could help to regrow damaged teeth. Two research engineers at the University of Alberta in Canada, developed the miniature device after ultrasound stimulation encouraged damaged teeth and 2) ___ tissue to regrow in animals. A scientist in Alberta’s medical faculty, was able to regrow teeth in rabbits with a larger device, but only when some tooth 3) ___ remained in place. The ultrasound device could help those who have had their teeth broken while playing high impact 4) ___ such as ice hockey and rugby. The tooth brace sends low-power ultrasound 5) ___ to the damaged tooth over many months. A piezoelectric crystal generates the ultrasound by vibrating at 6) ___ above 20 kilohertz when fed an alternating voltage from an oscillator charged by a battery. Physiotherapists often use ultrasound to help broken bones knit back together, although the healing 7) ___ is not precisely understood. One theory is that pressure waves mimic the effect of strenuous exercise, loading a bone and tricking it into generating more bone cells – a process called 8) ___. El-Bialy’s work on rabbits in 2003 (American Journal of Orthodontics and Dentofacial Orthopedics, vol 124, p 427) first showed that low-power ultrasound also encourages growth of dental tissue.
ANSWERS: 1) transmitter; 2) jawbone; 3) root; 4) sports; 5) pulses; 6) frequencies; 7) mechanism; 8) osteogenesis