Invisalign Retainers in Singapore TL;DR — Invisalign Retainers Guide (Singapore) Retainers keep your teeth in place after Invisalign  and stop them from moving back to their original positions. Most adults in Singapore wear  clear removable retainers  because they are comfortable and almost invisible. You must wear retainers  full-time for 3–6 months , then  only at night long-term  to maintain your perfect smile. Clean retainers with  cool water, mild soap, and weekly cleani