Check the listing for details. Dental Retainer Case Storage Mouth Guard Box Containers for Invisalign Teeth. Color: Purple, Condition: New. Listed at 3.95 USD. Vibrant and Diverse Colors: With a range of colors to choose from, match your case to your style or mood. We strive to exceed all your expectations and put a smile on your face. Easy to Clean: Simply wash with soap and water for a fresh, clean case.