Influence of handling-relevant factors on the behaviour of a novel calculus-detection device.
OBJECTIVE
The aim of periodontal therapy is always the complete debridement of root surfaces with the removal of calculus and without damaging cementum. We have recently demonstrated the feasibility of a surface recognition device that discriminates dental surfaces by mathematical analysis of reflected ultrasound waves. This principle should enable the construction of calculus detecting ultrasonic device. Pre-clinical test results are presented here.


METHODS
An impulse generator, coupled to a conventional piezo-driven ultrasonic scaler, sends signals to the cementum via the tip of an ultrasound device. The oscillation signal reflected from the surface contains the information necessary to analyse its characteristics. In order to discriminate different surfaces, learning sets were generated from 70 extracted teeth using standardized tip angle/lateral force combinations. The complete device was then used to classify root surfaces unknown to the system.


RESULTS
About 80% of enamel and cementum was correctly identified in vivo (sensitivity: 75%, specificity: 82%). The surface discrimination method was not influenced by the application conditions examined. A new set of 200 tests on 10 teeth was correctly recognized in 82% of the cases (sensitivity: 87%, specificity: 76%).


CONCLUSIONS
It was shown in vitro that the tooth surface recognition system is able to function correctly, independent of the lateral forces and the tip angle of the instrument.
Meissner
Grit
G
Unit of Periodontology, Department of Restorative Dentistry, Periodontology and Pediatric Dentistry, School of Dentistry, Ernst Moritz Arndt University Greifswald, Germany.
Oehme
Bernd
B
Strackeljan
Jens
J
Kocher
Thomas
T
D003728:Dental Calculus / Q000175:diagnosis* / Q000628:therapy; D003739:Dental Cementum / Q000033:anatomy & histology*; D003743:Dental Enamel / Q000033:anatomy & histology; D012534:Dental Scaling / Q000295:instrumentation; D004867:Equipment Design; D005240:Feasibility Studies; D006801:Humans; D016571:Neural Networks, Computer; D009991:Oscillometry; D010363:Pattern Recognition, Automated; D011312:Pressure; D012680:Sensitivity and Specificity; D014092:Tooth Root / Q000033:anatomy & histology*; D014464:Ultrasonic Therapy / Q000295:instrumentation; D014465:Ultrasonics