Did you know that those old metal fillings are made of approximately 50% mercury? Mercury is a nerve toxin. When a mercury filling is rubbed or heated it releases mercury vapor, so over many years the toxic exposure to mercury has the potential to have a negative effect on health. In addition, mercury fillings are harder than tooth structure, so when a tooth keeps expanding and contracting against a mercury filling, it can develop small crack lines which over time can turn into larger crack lines.

Teeth that have mercury fillings removed sometimes can be more sensitive than other teeth, and that is because of the nerve damage that was done by the mercury filling. Mercury causes the protective sheathe that is around nerve fibers to shrink away, leaving nerve fibers “denuded” and at risk of sensitivity. While the mercury filling is in the tooth, the tooth may seem to be doing fine, but once the mercury filling is removed, the act of drilling on a tooth with a damaged nerve system can make the tooth overly sensitive even if all precautions are taken such as placing a liner. Removing a mercury filling has its risks, as does keeping a mercury filling in the mouth, so the decision is often made between two possible negative outcomes – on one hand there is chronic mercury exposure, and on the other hand possible life-long tooth sensitivity. Tooth sensitivity does not always happen, but it happens often enough that the risk of sensitivity has to be taken seriously.

As for fluoride, it is too bad that it has systemic effects, because if we just talk about teeth it does strengthen teeth. The good news is that there is an alternative to fluoride which is biocompatible and has no negative systemic effects – it is called hydroxyapatite. Hydroxyapatite is another word for calcium-phosphate, which is the mineral that our teeth are made of. A cavity happens when the hydroxyapatite in our teeth dissolves away … and in the same way, enamel damage can be reversed if hydroxyapatite is applied to teeth as it strengthens the outer layer of enamel. Unfortunately when damage is into dentin and bacteria start growing in damaged dentin, hydroxyapatite does not help to get rid of the cavity infection, so a filling is still needed most of the time if the damage is deeper than enamel. While swallowing fluoride is a health hazard, swallowing hydroxyapatite has no negative systemic effects, so it is a great option to reverse enamel damage and to just strengthen enamel, especially in the grooves of teeth that have just recently erupted. We encourage parents to bring in their children to see holistic dentists because the benefits of caries prevention are lifelong.