A cracked tooth is a very common dental problem. Many people today manage to keep their teeth for longer but with age and circumstance, such as having mercury amalgam fillings can mean that the likelihood of a cracked tooth increases.
One of the many undesirable properties of old silver mercury fillings is that as they age and oxidize, they begin to expand. Your natural tooth structure wraps around the filling and as the filling expands, it puts pressure on the hard enamel and hairline stress fractures are created which in turn can cause your tooth to crack – (see picture 1 – Cracked tooth – Patient presented to Dr Dirk with pain on biting)
In the same way that mercury expands and contracts in a mercury thermometer, this too can happen in mercury amalgam fillings. Amalgam fillings contain approximately 50% mercury so when you have a hot drink, the mercury in the filling also heats up & expands which in turn makes the filling bigger. Conversely when you have something cold to eat or drink such as ice cream, your filling contracts leaving a gap around it. This puts a whole lot of pressure on your tooth & eventually your tooth can’t take the strain and may crack, fracture or fall apart.
There are a few physical processes going on when you have mercury amalgam fillings in your tooth, these are:
- Temperature changes within your mouth, which makes the filling expand & contract.
- The remaining tooth and the mercury amalgam filling moving in different directions when you chew.
- Drilling out large cavities to accommodate mercury amalgam filling(s) can destroy parts of the tooth that actually help to hold the tooth together.
- Severe teeth grinding – called Bruxism can lead to a cracked tooth.
Teeth can sometimes develop hairline fractures that can cause pain when chewing, biting or grinding (see picture 2 – Dr Dirk removed the old mercury amalgam filling to revealing the crack on the wall of the tooth)
What are your alternatives?
If any of the old mercury fillings that were replaced were extremely large and the remaining tooth structure has been compromised one option is to have a crown on the tooth, essentially covering the entire tooth and eliminating any possibility of a piece breaking off.
White bonded composite fillings are also a great alternative if the crack is not too severe. They have a similar expansion rate as your tooth, which means that the composite filling material will expand and contract just like your tooth with any temperature variations. Also, white composite fillings are bonded into the tooth cavity, which means there are no gaps around the edges (see picture 3, Dr Dirk has placed a new white composite filling repairing the clients cracked tooth)
Call today to make an appointment with Hobart holistic dentist Dr Dirk Jacobsen on 6234 5114.
Because it’s time to think differently about your dental health……