Abstract
The purpose of the present study was to examine the effect of neutral 2% and 0.05% NaF and acidic 2% and 0.05% APF solutions on Nickel (Ni) ion release and morphological change of the metal surface of two types of preformed metal crowns for the primary teeth in which metal crown A and metal crown B contain high and low levels of Nickel, respectively.Ni ion releases (measured as μm/cm2) from metal crown A and B were examined after immersion in each solution for 1, 3, 5 and 10 minutes.SEM observations of both crown metal surfaces, after immersion in four kinds of concentrations of fluoride solutions for 10 minutes, were made for the NaF and APF solutions, respectively.Both metal crowns showed greater Ni ion release in the 0.05% APF and 2% APF solutions than those in similar concentrations of NaF. Metal crown A showed more ion release than metal B.By SEM observation, both metal crown A and B immersed in the test solutions showed visible corrosive surface changes compared to before immersion, regardless of a different acid value. Moreover,more corrosive change of metal crown A was observed than that of metal crown B when immersed in the acid solutions of 2% and 0.05% of APF.Based on the amount of Ni ion release and SEM findings, it is clear that metal corrosive changes in preformed metal is affected by the contained Ni of the metal and the acidity of the immersion solution.
