Assessment of Nickel Release from Stainless Steel Crowns

Objective: adverse effects of dental materials, especially metals, have been an important issue in recent decades.purpose of study: the purpose of this study was to determine the amount of nickel released from stainless steel crowns in artificial saliva.materials and methods: in this in-vitro study, 270 stainless steel crowns were divided into five groups, each with nine subgroups. each group (i to v) was com-prised of four, five, six, seven and eight crowns, respectively. each subgroup was placed in a polyethylene jar containing artificial saliva and held in an incubator at 37°c for four weeks. the amount of released nickel was determined on days 1, 7, 14, 21 and 28, using an atomic absorption spectrophotometer. wilcoxon signed-rank and kruskal-wallis with dunn’s post hoc tests (spss software, v. 18) were used for statistical analysis at a significance level of 0.05.results: the mean level of nickel on day 1 was more than that of day 7; this dif-ference was statistically significant for all groups (p < 0.05), except for group ii (p = 0.086). also, the mean difference of released nickel between the groups was significant on day 1 (p = 0.006) and was insignificant on day 7 (p = 0.620). the nickel levels were zero on days 14, 21, and 28.conclusion: the amount of nickel was below the toxic level and did not exceed the dietary intake.