The electrophysiological properties of mechano receptive units in case of endosseous dental implants in the dog.

Research Project

Project/Area Number	60480423
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	補綴理工系歯学
Research Institution	HIROSHIMA UNIVERSITY
Principal Investigator	TSURU Hiromichi Hiroshima University school of dentistry ・ Professor, 歯学部, 教授 (90034157)
Co-Investigator(Kenkyū-buntansha)	KONDO Noriaki Hiroshima University school of dentistry, 歯科補綴学, 助手 (20162109) AKAGAWA Yasumasa Hiroshima University school of dentistry, 歯科補綴学, 講師 (00127599) NAGASAWA Tohru Hiroshima University school of dentistry, 歯科補綴学, 助教授 (20034168) SHIGENAGA Yoshio Hiroshima University school of dentistry ・ Professor, 口腔解剖学, 教授 (90028770)
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥6,500,000 (Direct Cost: ¥6,500,000) Fiscal Year 1986: ¥1,200,000 (Direct Cost: ¥1,200,000) Fiscal Year 1985: ¥5,300,000 (Direct Cost: ¥5,300,000)
Keywords	endosseous dental implant / sensory perception / mechanoreceptive afferent / electrophysiology / single fiber method / 下歯槽神経
Research Abstract	The response properties of mechanoreceptive units were examined by the single fiber method in endosseous dental implants in the dog, which were compared to those of control experiments. Three right mandibular incisors of twenty one dogs were removed and single-crystal sapphire endosseous dental implants were set in the edentulous ridge after three months. Three,six nine,twelve months after implantation, animals were subjected to the experiments. Responses were recorded from single fiber dissected from the inferior alreolar nerve. Square, ramp and Vibratory sine wave stimuli were applied to the implants using an electrically controlled mechanical stimulator. One hundred and thirty single fibers responding to the mechanical stimuli applied to implants were isolated. All of these mechanoreceptive afferents belonged to fast adgpting type (FA) and intermediate type (IM). Intensity functions of these units showed a linear relationship between the stimulus intensity and cumulative impulse number during the first second, and between displacement velocity and discharge frequency, which adgpted to logarithmic co-ordinates (log Y=a+b log X). The FA and IM types were classified into two types from the response properties to vibratory sine wave stimulus. one Showed typical tuning curve. The average of tuning points was 8.3Hz. The others did not have an optimal frequency and the threshold amplitude producing one to one discharge to the sinusoidal stimulus increased as stimulus frequency increased. The average conduction Velocities of mechano receptive units in control experiment and endosseous implants were 30.6m/sec and 20.5m/sec respectively. There were significant difference between them (P<0.01).