Applications of Ultrasonic Instrument in the Tooth Extraction

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A technique for tooth extraction using ultrasonic instrument was studied in basic and clinical application. An ultrasonic probe was inserted into the periodontal space for 60-90s to cut the periodontium under water coolant. After application of this probe the tooth was extracted with forceps to which a strain gage sensor was attached. The force applied to the sensor was transduced by an apparatus developed by us to improve the gnathodynamometer, and sequential changes of force during tooth extraction were recorded by a digital recorder and analyzed by a personal computer with our original software. The efficacy of this method compared with the conventional method used for the controls was evaluated in terms of the integrated force during extraction, duration of extraction. In the basic study, histological findings was investigated.1. Basic studyThe resulting mean values obtained of the integrated force during tooth extraction were 2.78x10^3 <plus-minus> 1.94x10^3 kg.s (8teeth) in the experimental group and 4.84x10^3 <plus-minus> 3.04x10^3 kg.s (8 teeth) in the controls (p<0.05). The mean durations of tooth extraction were 19.8 <plus-minus> 9.5s (8 teeth) in the experimental group and 32.8 <plus-minus> 15.4s (8 teeth) in the controls (p<0.05). Histologically, bone formation 2 and 3 weeks after extraction was slightly less in the experimental group than in the controls.2. Clinical studyThe resulting mean values obtained of the integrated force during tooth extraction were 1.77x10^3<plus-minus> 1.62x10^3 kg.s (12 teeth) in the experimental group and 7.00x10^3<plus-minus>5.61x10^3 kg.s (12 teeth) in the controls (p<0.05). The mean duration of tooth extraction were 10.5<plus-minus>8.10s in the experimental group and 36.5<plus-minus>30.5s in the controls (p<0.05). Delay of wound healings were not investigated.