Bio-mechanical acceleration of orthodontic tooth movement with the physical energy of ultrasonic and laser beam
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||SHOWA UNIVERSITY|
KANEGAE Haruhide Showa Univ., Orthodontic Dept., Assoc. Prof., 歯学部, 助教授 (90119173)
SHINOHARA Chikashi Showa Univ., Orthodontic Dept., Faculty, 歯学部, 助手 (00235558)
SAITHO Sigeru Showa Univ., Orthodontic Dept., Faculty, 歯学部, 助手 (20195986)
|Project Period (FY)
1991 – 1993
Completed(Fiscal Year 1993)
|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1993 : ¥200,000 (Direct Cost : ¥200,000)
Fiscal Year 1992 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1991 : ¥1,300,000 (Direct Cost : ¥1,300,000)
|Keywords||orthodontic tooth movement / bone remodeling / semiconductor laser / attenuance of laser / ultrasonic vibration / periodontal tissue / 半導体レ-ザ- / 歯の振動|
To investigate the possibility of bio-mecanical acceleration of orthodontic tooth movement with physical energy of ultrasonic and laser beam, we made several research on the following subjects.
1) basic study on the penetrative sensitibity of Ga-Al-As semiconductor laser (MORITA INDUSTRY, 790nm, 60mW, continuous wave) in living tissue
2) evaluation of the magnitude of living tooth vibration being in contact with ultrasonic chip (28kHz, amplitude : 10mum)
3) histological survey on peridontal tissue of Wister rat's molar being orthodontically moved by Waldo's method combined with the physical acceleration of ultrasonic vibration and/or laser beam
METHODS AND RESULTS
1) The amount and the distribution of the semiconductor laser beam on the penetrative sede were quantified. Tissues used in this study consists of mandibular cortical bone derived from human and ox, masseter muscle, fat tissue of ox and human venous blood which were all collected in fresh status on the same day of measureme
Percent transmittance of cortical bone in 1.0mm thickness reached 50% and the distribution of the beam power on the penetrativee side showed remarkable scattering and some absorption and scattering were observed. Blood indecated lower level of the transmittence ; the beam power seemed to be attenuated by absorption rather than scattering through blood.
2) Several upper molars of Wister rats among which orthodontic elastics had been inserted between M1 and M2 one week before measurement were used in this study. The upper jaw was fixed tightly on measuring equipment under wet condition immediately after the sacrifice.
Compared with the control sides (without elastics) the experimental sides showed remarkably higher frequency (3-11kHz) and larger amplitude (12-24mum).
3) 120-second laser beam were irradiated four times and 30-second ultrasonic vibration were given three times during 2-week experimental period.
According to the histological observation, laser irradiation accelerated the bone remodeling and tissue repaire of periodotium after tooth movement. On the othe hand, ultrasonic vibration enhanced bone resorption and delayd bone formation. Laser irradiation with ultrasonic seemed to decrease this phenomena. Less
Research Products (5results)