[A new method of measuring the cytotoxicity by spectrophotometer for amalgam of different cupric quantity]

The authors developed a new measuring cytotoxic method for biomaterials using violet-spectrophotometer. The principle of this test is that the more the cell exist the higher the concentration of stain occur. Base this phenomena, we may calculate the relative growth rate and evaluated the toxic grade of the tested materials according to the absorption in spectrophotometer. The merits are that it can avoid subjective factor of the operator; collect all cells tested; be more sensitive, simple and accurate than the cell growth rate test, agar overlay test and molecular filter test. Three kinds of different cupric quantity amalgam are tested using new measuring cytotoxic method. The content of copper is 6%, 13% and 24.6% respectively. The result shows that there is no evident cytotoxicity for these three materials after 2 days, but the cytotoxicity appeared and increased as the contacting time between the extract of material and cell goes on. On the other hand, as the content of copper increased. The cell relative growth rate decreased. It indicated that there may be certain relationship between the content of copper and cell growth rate.