Porcelain crowns should last for years before they need replacing. You could reasonably expect a crown to last for ten or more years, or even longer when made from zirconia. However, the longevity of a crown does depend on good aftercare. Regularly brushing and flossing around your crowns and visiting your general dentist for checkups and hygiene appointments will help to prolong the life of your crowns. It is important to understand that no restoration will last forever.