Clean the Retainer, Then Give It a Safe Home
Use a cleaning method suited to your retainer, protect it from heat and damage, and bring it to reviews so fit and condition can be checked.

Match the method to the appliance
The AAO advises gently brushing removable retainers with a soft brush and water, with a suitable retainer cleaner when appropriate. Ask your treating team for instructions specific to the material rather than assuming every appliance tolerates the same products.[1]
Clean the case too, follow product directions and avoid hot water or other heat that could distort the appliance. If deposits, odour or staining persist, bring it for advice instead of using stronger household chemicals.
Keep it out of napkins and pockets
Use the protective case whenever the retainer is out of your mouth. The AAO warns that napkins are easily discarded and that loose retainers in bags or pockets can break. Keep the case away from pets.[1]
Bring the retainer to scheduled reviews and report cracks, sharp edges or changes in fit. If you lose it, call promptly about replacement. A clean appliance still needs to fit correctly, and an intact one still needs the wear schedule prescribed for you.