Enhance Your Smile At Home In Minutes. Simple Fitting Instructions. Ultra Comfortable. Extra Thin Flex Technology Minimizes Speech Disruption. For Cosmetic Purposes Only, Do NOT Eat Or Sleep While Using This Product Fitting Instructions: Place teeth into a cup of hot (almost boiling) water for 1 minute. This will make them flexible and ready to custom fit. Using a mirror, firmly position the Instant Smile Teeth over your existing teeth. Press them firmly against your teeth and gently pat the impression material with your thumbs behind your real teeth. Gently ease the teeth out of your mouth after 30 seconds and set them in a glass of cold water to cool. The impression material turns white when it is hardened.