Well folks summer is here in full swing in sweltering Scottsdale, Arizona with temperatures hitting 120 degrees. No, I am not kidding you, it really is that HOT!!! One of the best ways us Arizonians stay cool is by hitting the movie theaters. And of course the more popular blockbusters being featured are IRON MAN® 3 and Man of Steel®. So I thought this would make a great blog topic; what make your teeth SUPER!!!
As I discussed in my earlier blog, acid wear from extrinsic food and drink causes the breakdown of the enamel or the white part of your tooth. So in essence acid is like to enamel what kryptonite is to Superman®.
In this blog I want to focus more on forces that our teeth take with everyday use. We consider our teeth hard. Enamel is the hardest substance in the body but this does not mean it is inert. Our teeth bend under load. Every day mastication or chewing will not break teeth but under the right circumstances it can fail.
For example if you have a cavity in your tooth, part of the tooth can be unsupported, causing you to break that tooth when you eat even salad or bread. It only will take small forces to break an unsupported part of a tooth that has decay. Think of termites in a house. You can’t see the damage and if you kick a rotten part even just a little it will cave in.
Attrition is another term that is the constant grinding or bruxism of your upper and lower teeth. This can start to wear your smile line and because it happens gradually you won’t notice it until one day your teeth look shorter.
You will start to notice the inner part of the tooth or the dentin as the teeth start to have wear. A lot of focus in dentistry has been to preserve the enamel however new research is showing how important the dentin really is. Scientists at the UCSF are observing that the dentin becomes brittle with age even in the absence of tooth decay or restorations. The cause of the brittleness is not known at this time but it is being studied at the molecular level. Softer than enamel the dentin is made up of part mineral, part collagen and part fluid. It is sandwiched between the enamel and the central chamber known as the pulp. At the microscopic level permeable channels or tubules run through the pulp to the enamel. Surrounding each tubule is a mineral build up called the cuff.
Using a SEM or scanning electron microscope, the researchers initiated cracks in the dentin to simulate wear and measure fractures. They found that the cuffs in the dentin act like steel rods or rebars in reinforced concrete by absorbing some of the stress load from crack and limiting the crack tip from spreading mainly by forming microcracks.
Aged dentin has more mineralization and is not as elastic so it can’t propagate the microcracks which inhibit the spread of the crack. So an aging tooth can fail with repeated stress load and crack generation by having a lower fatigue resistance. So basically age can make your dentin brittle and fracture-prone.
WOW! I know that is a lot of technical information but the basic gist is your dentin has been engineered to make your tooth tough.
If that is not SUPER than I don’t know what is!!!