By Ben Sutherland
BBC World Service
Simroid is attached to a computer, which works out her responses
Trainee Japanese dentists now have a way to avoid causing pain and damage if they mix up their molars - by practising on a robotic patient.
The robot, called Simroid, has sensors in its teeth and body which feed back on how well the dentist is doing.
Movements such as blinks and muffled gurgles are designed to show normal patient responses such as fear, discomfort, pain and tension - without putting any real person's mouth at risk.
"I made this robot so that students can understand patients' feelings," said Professor Naotake Shibui of the division of pediatric dentistry at the Nippon Dental University Hospital in Tokyo.
"Then they become a dentist who doesn't just concentrate on technique but also understands the patient. Everyone is a little afraid when they come to the dentist, and we should appreciate that," he told BBC World Service's Digital Planet programme.
Sensors in the robot's teeth trigger red lights to illustrate when a drill has gone too far.
However, the robot, which is designed to look like a female, has sensors in other areas on its body too, to provide feedback about the patient's whole experience.
The robot patient's open mouth simulates communication with dentists
Dr Shibui explained that when a dentist accidentally touches the robot's breasts, for example, it is indicated that the patient would feel uncomfortable.
"The whole training session can be recorded and you can review it anytime you want," he added. "We can stop the video and tell our students, 'you had a red light because you touched the patient here'."
The robot has also been designed so that when it speaks, it does so with the open-mouthed series of grunts familiar to anyone who has sat in the dentist's chair with a mouthful of foam.
Dr Shibui, who has been working on the project for two years, said that treating the robot as a real patient was essential to training.
"Actually talking to the patient makes you understand their feelings," he said.
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