No. KöR Whitening Deep Bleaching™ trays are very different. They’re comfortable; because they’re thin and form-fitting, you’ll forget they’re even in your mouth. They’re convenient; by wearing these only while you sleep, it doesn’t interfere with your busy day. Also, unlike regular trays, the KöR Whitening Deep Bleaching™ Trays seal the bleach inside the tray, preventing the gel from quickly leaking into your mouth.← Will the whitening trays be uncomfortable, difficult to sleep with or will the bleach leak out of the trays?