As my daughter is just about to have her braces removed, I asked my dentist what could be used as safe materials for her retainer. He said that titanium for the metal bar, and a clear plastic would be the best that he could think of. He is a really good dentist, as far as I can see. He used all the Huggins protocol and told me what supplements to get to detoxify. He seems aware of the issues. Does anyone know about the possible toxicity of titanium?