Why do my white fillings hurt?

Post operative sensitivity is very common after getting white fillings placed, but why? A lot has to do with the chemistry and physics of the filling material itself. Composite resins, or white fillings, are made of a plastic material that will expand and contract with temperature changes. This expansion and contraction is felt within the tooth and results in sensitivity. Most commonly, the sensitivity is within the first couple of weeks after getting a white filling replaced. After a couple of weeks, the tooth will get used to this movement and the sensitivity will go away. There are occasions when a white filling is too large for a tooth and the filling will need to be replaced with a crown.

White fillings are the material of choice for most dentists. This is because white fillings are chemically bonded to the tooth structure, enabling the dentist to do a more conservative preparation of the tooth structure. White fillings are also advantageous because they are esthetic. Dentist’s can place a filling that will be the same shade as your tooth so you can smile with confidence and no one will know that you have a filling.

Amalgam, or silver fillings, are the old standard fillings. They are not as commonly used because of the poor esthetic quality, the mercury controversy surrounding the material, and the cracking of the teeth that results after years of wear. Amalgam fillings are held into the tooth by mechanical preparation. The dentist prepares the tooth so that the filling is held into the tooth with the walls of the preparation. Because of this mechanical preparation, the tooth preparation is not as conservative as a white filling. Amalgam fillings are strong materials and can be used for larger fillings that composite resin materials aren’t designed to withstand. Where are white fillings are expanding and contracting, amalgams are constantly expanding. This expansion will push on the walls of the filling preparation and will result in cracks and splitting of the teeth. Like a crack in a windshield, the crack will continue to grow. You want to have your silver fillings replaced when the cracking begins because the cracks could go into the nerve, resulting in a root canal, or could split the tooth below the bone level which results in needing to have the tooth extracted.

White fillings are the new generation material in dentistry replacing the old amalgam fillings. It is a trustworthy, esthetic, and consistent material of choice for most dentists. Once you understand what the filling composition is doing inside your tooth, it’s easier to understand why you can have sensitivity with the material but also see the advantages of such material.