I don't like them because they break teeth! ... and it's technology from the 1800's (here's the wiki link to amalgams if you're interested in reading more history). Metals don't bind to teeth, and so the way silver fillings stay in teeth is by preparing the teeth in such a way as to prevent them from coming out - see photo below.
Over time (with cyclic fatigue) the stress areas tend to fracture. If the tooth's lucky, the fracture will be superficial, and not involve the nerve - in such cases, the tooth may be restored by a tooth colored filling, an onlay ('porcelain filling'), or if more extensive, a crown. If the tooth's not so lucky, the fracture line may extend to the pulp chamber of the tooth (where the nerve lives), in which case, the tooth may require a root canal and then a crown. Sometimes these fracture lines extend through the entire tooth, in which case, the tooth will need to be extracted!
I don't advocate removal of ALL silver fillings because that comes with its own risks - every time a dentist alters a tooth, the nerve gets temporarily irritated and sometimes, the nerve gets permanently irritated and requires root canal treatment. In addition, every time you remove silver fillings, you risk exposure to mercury because the filling will now overheat and release mercury particles and vapors (look for my future blog on rubber dam isolation to minimize/eliminate this risk.) However, I do always advocate removal of silver fillings when there's evidence of fracture lines, because I prefer to address the fracture preemptively rather than wait for the tooth to fracture unpredictably, potentially risking losing the tooth.
There are some studies that show silver fillings last longer than tooth colored fillings. This was historically the case, since dental resins were first developed in the 60s and 70s and did not become clinically acceptable for posterior teeth until the 90s. The latest composites have significantly improved since then. Composites are very much more technique sensitive than silver fillings, and if not placed properly, they will fail in a short number of years. However, if proper technique is followed (to be discussed in a future post) they could last just as long, if not longer!
Over time (with cyclic fatigue) the stress areas tend to fracture. If the tooth's lucky, the fracture will be superficial, and not involve the nerve - in such cases, the tooth may be restored by a tooth colored filling, an onlay ('porcelain filling'), or if more extensive, a crown. If the tooth's not so lucky, the fracture line may extend to the pulp chamber of the tooth (where the nerve lives), in which case, the tooth may require a root canal and then a crown. Sometimes these fracture lines extend through the entire tooth, in which case, the tooth will need to be extracted!
I don't advocate removal of ALL silver fillings because that comes with its own risks - every time a dentist alters a tooth, the nerve gets temporarily irritated and sometimes, the nerve gets permanently irritated and requires root canal treatment. In addition, every time you remove silver fillings, you risk exposure to mercury because the filling will now overheat and release mercury particles and vapors (look for my future blog on rubber dam isolation to minimize/eliminate this risk.) However, I do always advocate removal of silver fillings when there's evidence of fracture lines, because I prefer to address the fracture preemptively rather than wait for the tooth to fracture unpredictably, potentially risking losing the tooth.
There are some studies that show silver fillings last longer than tooth colored fillings. This was historically the case, since dental resins were first developed in the 60s and 70s and did not become clinically acceptable for posterior teeth until the 90s. The latest composites have significantly improved since then. Composites are very much more technique sensitive than silver fillings, and if not placed properly, they will fail in a short number of years. However, if proper technique is followed (to be discussed in a future post) they could last just as long, if not longer!
Plus, composite looks much better than silver.
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