Metal ion release from silver soldering and laser welding caused by different types of mouthwash

Abstract

Objective: To compare metal ion release from samples welded with silver soldering and laser welding when immersed into mouthwashes with different ingredients. Materials and Methods: A total of 72 samples were prepared: 36 laser welded and 36 silver soldered. Four samples were chosen from each subgroup to study the morphologic changes on their surfaces via scanning electron microscopy (SEM). Each group was further divided into four groups where the samples were submerged into mouthwash containing sodium fluoride (NaF), mouthwash containing sodium fluoride + alcohol (NaF + alcohol), mouthwash containing chlorhexidine (CHX), or artificial saliva (AS) for 24 hours and removed thereafter. Subsequently, the metal ion release from the samples was measured with inductively coupled plasma mass spectrometry (ICP-MS). The metal ion release among the solutions and the welding methods were compared. The Kruskal-Wallis and analysis of variance (ANOVA) tests were used for the group comparisons, and post hoc Dunn multiple comparison test was utilized for the two group comparisons. Results: The level of metal ion release from samples of silver soldering was higher than from samples of laser welding. Furthermore, greater amounts of nickel, chrome, and iron were released from silver soldering. With regard to the mouthwash solutions, the lowest amounts of metal ions were released in CHX, and the highest amounts of metal ions were released in NaF + alcohol. SEM images were in accord with these findings. Conclusions: The laser welding should be preferred over silver soldering. CHX can be recommended for patients who have welded appliances for orthodontic reasons. (Angle Orthod. 2015;85:665-672.)

Metal ion quantification in the saliva of patients with lingual arch appliances using silver solder, laser, or TIG welding

“…Previous studies comparing silver solder and laser welding showed more metal ion release for soldering [16,22,40]. In this study, Zn, Ag, and Cd ions showed no difference in variation along the periods among the groups, concluding that there was no significant increase in the release of these ions when comparing the groups.…”

“…In group 4, for Ni ions, there was a statistic difference from T4 to T1 (P = 0.001), T4 to T2 (P = 0.017), and T4 to T3 (P = 0.001), indicating that TIG-welded appliances had greater Ni ion release and that this increase in ions did not regress during the assessed period. The level of metal ion release from samples of silver soldering was higher than from samples of laser welding in a previous study [22], with greater amounts of Ni, Cr, and Fe released from silver soldering by different types of mouthwash [22]. Whereas the methods of the experiments vary, the results differ, and the comparison is difficult to be made.…”

“…Laser welding is an alternative to silver solder, in which the use of a third metal or alloy is avoided as the energy generated by the laser already promotes the melting of the metals. As such, it appears to be less susceptible to corrosion and more biocompatible [17,22,23]. Some authors [24,25] support the fact that laser welding is less toxic than silver solder.…”

Nickel ion release from dental alloys in two different mouthwashes

“…Listerine is an alcohol-based mouthwash. In this regard, Erdogana 21 studied the metal ion release from silver soldering and laser welding caused by different types of mouthwash and reported that NaF+alcohol (Listerine) mouthwashes exhibited the highest amount of metal ion release.…”

Effect of oral antiseptics on the corrosion stability of nickel‐titanium orthodontic alloys

“…Higher release of titanium in nitride‐ and rhodium‐coated alloys in Listerine may be because this antiseptic contains the highest concentration of hydrofluoric acid causing the damage of the surface layer. Additional release of metal ions above saliva after exposure to oral antiseptics is reported earlier, higher in those based on alcohol and fluorides than chlorhexidine, and least in aqueous solutions of herbal extracts . Ion release could be also related to microstructure of the alloy .…”