How exactly do you fill a cavity?

Excellent question. Everyone seems terrified of the dreaded cavity! It just sounds scary and gross. Many people don’t realize how non-invasive a filling can be when treating a small cavity or even multiple small cavities. Sure, when a cavity gets bigger and approaches the nerve, it becomes a little more complicated and technique-sensitive; symptoms and other factors need to be evaluated to anticipate the best possible outcome, but the treatment for small cavities is really very simple and routine!


First off, I like to numb every patient for a true cavity filling. If the decay is just into the soft part of the tooth, which is ideally when I will treat them, it is just good dental practice for your experience as a patient.


After the application of a topical gel to numb the tissues, you will most likely be numbed with some lidocaine or Septocaine®, depending on the tooth, area, patient, and practitioner. After letting the anesthetic take its effect, the caries (or decay) can be removed. This is usually done with a handpiece that is motorized to turn a rotary instrument which has flutes designed to minimally cut the tooth structure, in order to remove just the area that the bacteria has affected. After I can visually see that the cavity is removed, using my xray for supplemental information, I usually use some hand instrument to feel the area and confirm that the caries is gone, or in some cases just mostly gone (a topic for another day).


Next, the assistant and I need to keep the area well isolated to place the filling in the newly prepared cavity. Our materials do better without moisture, and as you can imagine – in the mouth, this is no small task. I use a piece of equipment called an Isolite that lets you rest your jaw, and it has a nice suction feature that removes extra fluid in the area but sometimes cotton rolls and Dri-Angle do just fine. If the filling is between the teeth, we use a matrix to keep our filling material on the tooth we want.


We need to etch the area, which is applying a gel to the tooth to start the creation of the bond of the filling material to the tooth structure. The etch is rinsed (and we hope you don’t taste it, because it is super sour!), then I use a single-step bonding agent that is painted on the tooth and air thinned to evaporate out its solvents and carrier agents. The bond is activated by our curing light for a couple of seconds, and then the white filling material is placed in the prepared area in small increments to avoid any force from shrinkage that would be applied to the walls. The application of the material is truly an art. It takes time, technique, and patience. It becomes a dance with the assistant. The white material is cured after each and every increment, and the final increment should create a nice seal. Then I trim the restoration, polish, and sometimes apply a glaze to the most superficial portion. We check the bite and the contacts with the adjacent teeth, and make sure you know not to take the tooth for a test meal until all anesthesia is gone!

That’s it! You are done. Now, that wasn’t so bad!