how long should you keep teeth whitening gel on?
Unless directed otherwise, wear Opalescence 10% for 8-10 hours or overnight, Opalescence 15% for 4-6 hours, Opalescence 20% for 2-4 hours, and Opalescence 35% for thirty minutes. Remove Excess gel with clean finger or soft toothbrush. Rinse twice; do not swallow rinsed gel.