Objective To study the interleukin-8（IL-8） levels in gingival crevicular fluid（GCF） of porcelain teeth
coated with Ni-Cr, Co-Cr or gold alloy at different time periods, and to uncover the degree of stimulation by these
alloys on gingiva at different time periods. Methods 45 cases of porcelain teeth coated with Ni-Cr, Co-Cr or gold
alloy were selected randomly, with 15 cases in each group. Sandwich enzyme-linked immunosorbent assay（ELISA） was
used to determine the concentration and total amount of IL-8 in GCF. The assay was done before treatment, as well
as at 1, 3 and 6 months post-treatment. Results The total amounts of IL-8 and GCF volume in the Ni-Cr alloy
coated porcelain teeth were higher in different time period than those before treatment（Plevels in Co-Cr and gold alloy coated porcelain teeth returned to pre-dental restoration after 3 months. Otherwise,
the levels of IL-8 concentration in GCF showed no significant difference among the three different alloys coating at
different time periods. Conclusion IL-8 is an important cytokine during tissue inflammation. Therefore, the level of
IL-8 in GCF is a useful criteria for the evaluation of stimulation degree on gingiva by different alloy coating materials
in porcelain teeth. The clinical choice of different alloy coating for porcelain teeth should be considered accordingly.
