Conclusion Nursing intervention can effectively decline the incidence rate of enamel demineralization for adolescent patients with fixed orthodontic appliance.

Polyurethane can be used as adhesive, resin for filling, root canal filling material, implant, orthodontic appliance, tissue engineering and so on in the field of dentistry.

Along with the development of laser welding in dental alloy welding, it was gradually applied in orthodontic appliance for weld of Ni-Cr alloy, Co-Cr alloy or Titanium alloy.