OBJECTIVETo investigate the immunological function parameters in patients undergoing dental restoration of nickel-chromium (Ni-Cr).

METHODSSeven hundred and ninety-five Ni-Cr alloy consumers as exposure group, together with 198 controls, were surveyed by the questionnaire and the biological examination of immunological function.

RESULTSAfter splitting all subjects into three groups of equal sample size by urinary Ni or urinary Cr, serum interleukin-1beta(IL-1β) was found to be significantly higher in the group of urinary Ni > 115.73 µg/mol creatinine comparing to the group of urinary Ni < 37.28 µg/mol creatinine (P < 0.05). No changes of immunological parameters in surm [tumor necrosis factor-alpha (TNF-α), IL-1β, and IL-6] were found in other groups of urinary Ni or Cr. Both one way analysis of variance (ANOVA) and linear regression analysis did not find any association between serum changes of immunological parameters and the parameters of alloy restoration (period, number and the level of metal crown uncovered with porcelain).

CONCLUSIONSThis study did not show positive associations between dental restoration of Ni-Cr alloy and serum levels of TNF-α, IL-1β and IL-6.