Even though current dental materials are very durable and look great, they will not last forever. On average, you can expect a "white" filling to have a 7-10 year lifespan. It is important to remember that this is an average and some may last less and some more. Someone with perfect oral hygiene and low wear and tear can expect a higher lifespan. On the contrary, someone with poor oral hygiene or clenching and grinding habits, can expect a shorter lifespan. Sometimes, it is not the filling that has not lasted, but a new cavity that has occurred in the tooth and the filling needs to be replaced to remove the cavity.