Why do I Need a Crown to Replace Old Fillings

Why Replace The Old Filling?

Many people are a bit surprised to learn that their old fillings cannot simply be replaced with a new filling. In fact, it’s quite common for the patient to be surprised that the filling needs replacing at all, as they do not have any pain or sensitivity in the tooth.

Whether you have pain in the tooth or not, it is important to understand why the filling needs replacing in the first place. 

Traditional amalgam (silver) fillings are composed of various different metals, including mercury. In preparation for an amalgam filling, the dentist had to undercut the tooth after decay removal to hold the amalgam filling. These metals in amalgam fillings expand and contract with hot and cold. When you eat hot foods, your fillings expand. When you eat cold foods, your fillings contract. Each time this happens, the fillings place a stress on your tooth structure and create a gap between the tooth and the filling. Over time, the gap allows bacteria to become trapped and cause decay to form. It can also cause microfractures due to the stress of contraction and expansion, which can cause a portion of the tooth to break off.

Why Not Just Replace With A New Filling?

You may be wondering; if the filling lasted this long, why can’t another filling be placed again? While it would be ideal to simply place another filling, it’s important to keep in mind that your dentist will need to remove not only the old filling, but the decay and microfractures underneath, as well.

In most cases, once the decay has been removed, there is not enough tooth structure to support another filling that will provide a definite long-term positive prognosis. For this reason,  the protection of the crown helps ensure the longevity and integrity of the tooth.

The crown will be designed to match the shade of the surrounding natural teeth, and will be blended into your smile. You will be able to rest assured knowing that your tooth is protected while enjoying a beautiful and complete smile line.

Willow Glen Dental Center: San Jose Dentist

Willow Glen Dental Center is proud to offer comprehensive crown services. For more information about dental crowns in San Jose or to get scheduled for an appointment in our San Jose dental office, give us a call at (408) 266-6144.