The Bottom Line: Whitening Vs Laser Lightening With lightening trays, the peroxide itself releases oxygen molecules that leak right into the external layer of your tooth, called enamel, and damage down stains over a few hours. Lasers are various because they heat up the oxygen process quicker [Ho, 2013] Nonetheless, if you have delicate teeth currently, or have actually had previous damages to your teeth, you may be more at risk to sensitivity after the laser bleaching procedure. The decision ...