アブストラクト(17巻1号:神奈川歯学)

神奈川歯学

Japanese

Title : 振動刺激がラット歯槽骨に及ぼす影響について
Subtitle : 原著
Authors : 宇治文孝
Authors(kana) :
Organization : 神奈川歯科大学補綴学教室第一講座
Journal : 神奈川歯学
Volume : 17
Number : 1
Page : 49-66
Year/Month : 1982 / 6
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「緒言」 咀嚼圧や咬合圧を上下顎残存歯に均等配分することは, 残存組織の保全からみて非常に重要な事項である. とくに欠損補綴においては, 支台歯がその生理的負担能力を越えて種々な傷害をうける危険性が高い. これに関して外傷性咬合や矯正力などの外力による歯および歯周組織の反応を病理学的に追究した研究はあるが, 負担能力の程度を計数的に直接求めたものは殆んどない. また, 補綴領域における外力に対する歯および歯周組織の反応に関する研究は模型実験にとどまるものが多い. 芳本は咬合力に対する歯および歯周組織の力学的変化について初めて生鮮骨を用い, 光弾性皮膜法とストレンゲージ法を併用して, 歪み分布を検定した. しかし, 力の大きさとの関係や生体反応はみることができなかった. この種の実験に用いられる加圧法は静的荷重が主である. 白沢らは口腔内での荷重は単なる静的荷重ではなく衝撃的なものが多いと考え, 歯に加わる力の性質を知る手段として加速度計を応用した動的荷重による振動実験を行ない, 歯の共振周波数を求めている.
Practice : 歯科学
Keywords :

English

Title : Effects of Vibratory Stimulus on the Alveolar Bone of Rats
Subtitle : Original article
Authors : Fumitaka UJI
Authors(kana) :
Organization : 1st Department of Prosthetic Dentistry, Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 17
Number : 1
Page : 49-66
Year/Month : 1982 / 6
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : Abstrac : In recent years there have been studies in various fields of dentistry observing pathological reactions to force but relatively few studies using vibration as a load. In particular, there are no studies where the rate of vibration and frequency have been set. In the present study "pink noise", a type of random noise, was used to exert vibration on the mandibu lar left first molar of rats. The acceleration rates were 0.1 G, 0.3 G, and 1.0 G and the frequency band widths were 125 Hz, 400 Hz, 1 KHz, 2 KHz and 4 KHz which when combined alternately gave a total of 15 separate vibratory conditions. Serious sections were prepared and compared with those for a control group. The extent of remodelling in the alveolar bone was examined histologically and with X-rays. Then, a lead-acetate time marking method was used to perform semi-automatic image analysis in measuring the area of remodelling in the alveolar bone. A quantitative analysis produced the following results. 1) The set of conditions which produced the most histological change on the tooth and periodontium was at 1.0 G acceleration and 125 Hz bandwidth. There was no difference from the control group at 0.1 G acceleration (except for bandwidths of 125 Hz and 400 Hz). 2) Pathological fiindings in the tooth and periodontium consisted chiefly of remodelling in the alveolar bone as was also the case when orthodontic force or traumatic occlusion was the external force. 3) Observation of separate areas revealed an absorbed appearance in the mesial and distal surface of the mesial root and in the distal alveolar surface of the distal root. 4) Estimates of the extent of bone remodelling under conditions of 1.0 G and 125 Hz bandwidth showed 95.06×103mm3 which was only 49.5% of the figure for the control group.
Practice : Dentistry
Keywords :