The dental patient's face is blue, very blue. But the customer in the dentist's chair isn't suffering and is blue because it's only a mannequin, part of Dublin Dental Hospital's virtual reality dental-training laboratory.
The hospital, which houses the Trinity College School of Dental Science, is the first to use the final version of the DentSim system, a computer-based training package for dental students.
Israeli company Den X combined its software with tracking technology developed in Canada to create the latest innovation in dental training. Although virtual reality is now used in many medical colleges, dental applications are relatively new.
While water spurts and drills whine, DentSim tracks and records a student's movements during assigned procedures to within two-tenths of a millimetre.
Based on information from infra-red tracking sensors located in the mannequin's eyes and nose and the handles of the dental instruments, three images are displayed on a 17-inch computer screen.
The main image, a close-up of the mannequin's head and mouth, is flanked by two angles of the tooth under repair. Using a computer mouse, these images can be rotated or enlarged for a more detailed view.
As students ready cavity and crown preparations, colour changes on the computer-generated image indicate the level of penetration within the tooth. On the screen, decay is green; the live section of the tooth, or dentine, is yellow, and the inner section is red.
When the procedure is over, the user's performance is evaluated against an optimal result and an overall score is delivered. The student is then - interactively - shown where errors were made and offered suggestions and guidelines for better performance. The work may be replayed, saved or submitted for evaluation by instructors.
Lecturer Frank Quinn believes virtual reality makes great sense in dental training because it improves students' sense of depth. "Students are so used to looking at screens. Sometimes it's hard to visualise procedures so there's great sense in enhancing it, as part of training, in a three-dimensional way."
The technology allows lecturers to programme detailed assignments and record a student's work for later evaluation. The plastic teeth are also removable for examination.
Customisation is important, said Mr Quinn, because approaches and philosophies varied from school to school. "New procedures may be added; just the software will change."
The results of trial runs with students using DentSim are positive. "The students have done amazingly well and enjoy working on it," he said.
This technology may be used by practising dentists, or those out of dentistry for a number of years, to try new procedures and self-evaluate surgical technique. This reduces the school's need for real patients during training exercises.
Besides training, the greatest application of the technology is expected to be research. As well as developing new surgical techniques and dental training methods, the hospital is working with the manufacturers to improve DentSim.
Dr Frank Houston, senior lecturer/consultant in restorative dentistry, said: "We hope to compare the effectiveness of the DentSim interactive environment in developing student skills as opposed to the traditional environment of feedback and comment from dental insructors."
The hospital is now testing four DentSim units and hopes that faculty and students will be using it in three months.