A patient came to see us at Time Dental for their routine healthy mouth review having not been to see us for quite some time. She had some old mercury amalgam fillings which had been in place for over twenty years, and at her last healthy mouth review she was advised that they needed replacing as they looked to be failing. She was not experiencing any symptoms at the time and preferred to leave them for the time being.
On her most recent review we found that the teeth with mercury amalgam fillings now had cracks running down the sides of the teeth. This progression is very common to see mercury filled teeth and is better to be dealt with in the very early stages as things get progressively complicated if left in place.
Mercury fillings expand and contract over a period of time and combined with strong downward chewing forces can eventually result in micro enamel cracks occuring in the teeth. At some point either the filling or the tooth will break. When visible vertical cracks can be seen the tooth normally needs something much more robust to prevent the crack from propagating and splitting the tooth. Porcelain or metal ceramic crowns are tooth coloured restorations which help to protect the broken tooth from splitting. If amalgam fillings are relatively small to medium sized and they are at their early stages of failing they can normally be replaced with white composite fillings. However if they are failry large in size either onlays or crowns are recommended as they also cover the biting surface of the teeth which protect the weaker parts of the tooth.