Abstrait

Potential Leaching of Hazardous Metal Ions from Soldered Orthodontic Appliance

Nora Rizka Mohamad, Khairil Aznan Mohamed Khan, Murshida Marizan Nor and Haizal Mohd Hussaini

Orthodontic soldered appliances used in a dynamic environment of the oral cavity may undergo corrosion process hence exposing patients to possible toxic effect of metal ions released from the process. This exploratory study aimed to assess and compare the leaching potential of hazardous metal ions from two types of silver soldered orthodontic appliance and to determine the conformity of the leached metal ions with the established health and safety standards published by World Health Organisation (WHO). Two types of soldered appliances (Transpalatal arch and Quad helix) were immersed in solutions with pH 2.5 to 5.5 (Hydrochloric acid) for a prolonged period of 22 weeks. The release of silver (Ag) and nickel (Ni) was determined by using a spectrophotometer. Results showed that metal ions were released the highest in the most extreme acidic condition (pH 2.5) and the pattern of metal release was dissimilar between types of metal ion and pH. There was no significant difference (p>0.05) in the release of ions between two types of soldered appliance and some of the metal release exceeded safety value published by WHO. Leaching of metal ions from silver soldered appliance immersed in acidic solutions was observed in this study. The potential of metal toxicity carried by this appliance must be carefully considered when advocating this appliance to patients.