One of the hottest topics of online dental discussions has to be the safety, or otherwise, of amalgam fillings.
The reason for this controversy is that amalgam is a mix of metals including 50 percent mercury, a liquid metal known to be a potent neurotoxin. The concern is that mercury can leach out of the fillings, leading to health problems.
Amalgam fillings have a long track record, coming into common usage almost 200 years ago. The material was cheap, simple to use and strong enough not to break under chewing loads, so it gained widespread acceptance within dentistry.
The health risks of amalgam have been repeatedly scrutinised by many of the world’s health authorities. Their conclusion, based on numerous studies, is that mercury leakage from amalgam fillings does not pose a measurable health risk to adults or children over the age of six.
So amalgam fillings are safe, cheap and effective, and therefore still widely used. From a clinical perspective, however, there are several lesser-known drawbacks to amalgam fillings:
1. Amalgams break teeth
A significant problem with amalgam fillings is that they dramatically weaken teeth. After years of wear, it is common for amalgam-filled teeth to develop structural cracks next to the fillings. Every day, we see numerous examples of amalgam fillings that have fractured teeth. Repairing the damage often requires major restorative care such as crowning and root canal treatment, or implant replacement if the tooth is unrepairable.
2. Amalgam fillings require more tooth removal
Amalgam doesn’t bond to tooth structure and must have sufficient bulk for retention and to resist fracture. For this reason it is generally necessary to sacrifice healthy tooth structure to provide retention and bulk for amalgam fillings. This irretrievably weakens and damages the tooth, making it more susceptible to later problems.
3. Amalgam fillings leak, causing recurrent decay
Amalgam fillings aren’t bonded to tooth structure, so there is a microscopic gap between the filling and the tooth. This provides a pathway for bacteria and nutrients to reach the inside of the tooth and begin the process of decay all over again, causing significant damage over time. Under most of the amalgam fillings we remove, there is decay.
4. Amalgam is ugly
No one wants a black tooth and that is exactly what amalgam looks like. Not only does the surrounding tooth appear grey, as the metal corrodes amalgam fillings can also stain or tattoo the remaining tooth structure.
For these reasons, as well as the fact that we don’t like working with liquid mercury, DentalPlus doesn’t currently offer amalgam fillings.
Instead, we have developed a tooth-coloured filling system we call UltraTough, a blend of carefully selected materials bonded into teeth in layers to provide durable, decay-resistant (and invisible) fillings. Ultratough fillings will be the feature of a future blog post, so please check there for more details.