So if silver fillings aren’t dangerous due to Mercury, why are people moving away from them?
Clearly, some dentists aren’t. They are a tooth restoration with a proven track record. They last for a long time and they are simple, quick and inexpensive to place. If you’re working on back teeth that no one is going to see, why not just do silver fillings?
There’s certainly an argument to be made for that. Besides their metallic color, silver fillings have a couple other weaknesses.
- strength only in bulk: Silver fillings are pretty strong, but there has to be a pretty big bulk of material. Anything less than about 2mm in depth or width is likely to fracture. This isn’t much of a problem if you have big spots of decay. But lets say you have a small cavity. The perfect example of this is a “groove cavity” in a back tooth. Often these cavities are relatively deep but very narrow. This narrowness doesn’t allow for the proper bulk of silver filling material. But it doesn’t make sense to widen the cavity for material. When you remove more tooth structure you actually weaken the tooth. There may not be problems in the first year, 5 years or even longer. But over time, a tooth weakened by removing extra tooth structure can crack and even break. Which could lead to pain and the need for more expensive dental work. Teeth can break for lots of reasons, but removing tooth structure to restore teeth is a common cause. As Dr. John Kois says, “the best dentistry is no dentistry.”
- not bonded: in order to stay in a tooth silver fillings need to be placed into an undercut area. The material goes into a cavity in a soft, packable form and sets up hard. So when it’s placed into an undercut as a soft material and then hardens up, it stays in the tooth. This causes a similar problem, though. Often more tooth needs to be removed in order to make an undercut.
Modern bonded fillings use a chemical bond to stay in place. They are placed with a kind of “tooth glue” that doesn’t require removing any more tooth structure than what’s needed to clean out the tooth decay. In this way, bonded composite fillings can require less tooth structure to be removed. Which may result in a smaller likelyhood of tooth fracture down the road.
There are options that require the removal of less tooth structure that can be used as well. They look more like teeth and they are actually bonded to the tooth structure. They are MUCH more difficult to place well. They require much drier conditions and take a lot longer to place correctly. Bonded fillings are hands down my favorite restoration to place! When done with care they are beautiful and quite durable.
Questions or comments about this post? I’d be happy to answer them! Email me at firstname.lastname@example.org or call the office at (989) 799-9133. We would love to be your Saginaw dentist!