So you have a cavity, a broken tooth or an old leaking or breaking filling that requires attention. In my view, if the area of the tooth affected is greater than two thirds of the surface area of the tooth, then you have a choice to make: a plastic (aka composite) filling or a lab fabricated partial crown (also called onlays). A filling of this size is generally around $275. It is stacked in a jelly form into the tooth where it is then light cured to become hard. You can imagine that its strength, while incredible for the jelly-to-rock transformation, is somewhat limited as compared to a partial crown constructed outside of the mouth and then glued in place.
Partial crowns/onlays are fabricated with modern chemistry, under pressure and subjected to massive crystallization heat - outside of the mouth of course! Partial crowns cost $1100 and require only two hours to make start-to-finish. They can be done with no temporary filling if you are in a digital office like ours, or two weeks if a dentist sends out to a lab while the patient wears a temporary filling. If the problem area on your tooth is smaller than two thirds of the surface area of the tooth, then the modern composites offer great strength at that size, look great, flex like a natural tooth, and provide a unifying strength to the tooth due to its adhesive nature. But will a filling last if it is two thirds or greater? Maybe. And that’s where the decision rests. Let’s jump right into the main question.
Ask yourself if you mind the filling not lasting in order to save the money or if you would prefer to spend a little more to have something that will last longer. (Yes insurance covers both, just be sure to have great photos/xrays and maybe even a pre-authorization from your insurance company for an onlay).
If money were not a consideration, I would choose an onlay. I would choose a more flexible material such as Lava Ultimate if it was slightly smaller and on a premolar, or Emax if it was slightly larger and/or on a molar. That said, stopping decay or handling a problem immediately with a filling is much better than letting it go or blowing your budget on a single tooth if you have several teeth to work on. I’ve done large composites that last for years. It’s an especially common choice for students and people getting started or restarted in the workplace who just need to buy a little time. We monitor these large fillings closely. After a few years or in the event of breakage, often the patient is ready to graduate the filling to an onlay.
There is no right or wrong answer; just a risk-tolerance preference and financial comfort level assessment.
I hope this post helps you decide between a partial crown/onlay or a filling. If you have any questions, please feel free to comment below or contact our office.
Thank you for your interest.