Evaluation of nickel releasing from stainless steel crowns regarding to “trimming”: An in vitro study

摘要

Context: Stainless steel crowns (SSCs) are the most durable and effective restorations for the primary teeth. Allergy to nickel as major components is common. Aims: The purpose of this study is to evaluate the effect of pH, time, oral temperature, and SSCs trimming on the nickel releasing. Settings and Design: This in vitro study was done on 18 same size crowns. Subjects and Methods: Group A (without trim 0 and Group B (with trim) were immersed in 5 ml artificial saliva. The amount of nickel releasing in each 18 subgroup composed from 3 pH (3.5, 5, and 6.75) and 3 temperatures (27°C, 37°C, and 47°C) in 3 times (1, 7, and 21 days), was measured by Atomic Absorption Spectrophotometer. Statistical Analysis: Data were analyzed by SPSS software (SPSS 20, IBM, Armonk, NY, USA) and use of t-test, Duncan, and Tukey's test for analysis of variances. Results were reported with 95% confidence. Results: The amount of nickel releasing reduced with crown trimming, significantly (P = 0.0001). A significant difference was observed in the amount of released nickel in temperature 47°C in comparison with 37°C (P = 0.0001); this measurement was not significant between 47°C and 27°C (P = 0.442). There was no significant difference between concentration of released nickel in 3 pH conditions and also in 3-time situations. The concentration of nickel was lower in trimmed group in comparison to intact group (P = 0.0001). Conclusions: The concentration of released nickel decreased with trimming of margins and increased when temperature increased. Time and pH had no significant effect on released nickel.