Retainers are made of a thermoplastic material that is sensitive to excessive heat, so they should be kept away from heaters, dishwashers, car dashboards or any place where the temperatures exceed 115 degrees(F).
The retainers should be cleaned before and after placement in the mouth. Because the material used for fabrication is slightly porous, plaque tends to cling to the surfaces of the retainer. Gentle scrubbing with a toothbrush and a mild liquid soap will remove the plaque.
A denture cleaning solution, such as Efferdent, will aid in the removal of plaque and tartar. Be sure to rinse the retainer thoroughly after cleaning to remove any cleanser residue.