[Cellular responses to vibration during dental drilling with belt drive motor engine (in vitro) (author's transl)].

There have been many reports on the pulpal reaction caused by vibration during high speed dental drilling with air turbine hand-piece. It is, however, not clear pulpal responses to vibration of low speed drilling with 7 000 rpm of belt drive motor engine which produces a fundamental vibration of about 170 cps having most unpleasant sensation at vestibular apparatus. Here, cellular responses of L strain cells to vibration derived from 7 000 rpm and 15 000 rpm of belt drive motor engine were observed in vitro system. There is no difference between the both cellular responses to the vibration of 7 000 rpm and 15 000 rpm. Suspended free cells were easily influenced and degenerated by the vibration, and remarkably checked in their cell-multiplication. On the contrary, in the cells adhered to the substratum of glassware, no degeneration and no inhibitory effect were observed. And the cells showed reversible response of cytoplasmic shrinkage only.