HERE IS EXACTLY WHAT TO DO: 1) Breathe. You can handle this. 2) Find the crown and rinse it gently with water. Don’t scrub the inside — leave any debris for your dentist to clean. 3) Double check the orientation. It only fits one way. 4) If you have temporary dental cement (from a pharmacy): dry the tooth and crown, place a tiny amount inside, and reseat it. 5) if you don’t have access to temporary dental cement, a dab of toothpaste or even denture adhesive can be used to hold a crown in place u