Most patients have old fillings that are amalgam or metal based fillings. The materials that these fillings are made of last around 8-10 years. After that time, the material starts to break down and the fillings start to show signs of leakage. Over time, the leakage can lead to new cavities under the old fillings.
I took some photos of my dental assistant's teeth to show you what happens to old fillings. She is a young lady and these fillings have been in her mouth for 12 years. She is not having any problems with them. The fillings just are turning black in color.
Now I will show you a photo of what the teeth look like after I remove the old fillings. You will notice that there are new cavities under all three fillings. The center one is particularly bad. There is significant decay and there are cracks on this tooth.
What causes the cracks? The physical property of metal is that it expands more than natural teeth when it gets hot. So every time when you drink coffee or soup, the filling expands. Over a long time, like 10 years, the daily expansion of the filling leads to excessive stress on the surrounding teeth, hence causing cracks. By the time we remove the new decay, there will be very little sound tooth structure left. This tooth will need a crown.
I like to recommend that patients replace their small and medium sized old fillings. By doing so, you will prevent major cracks on teeth and reduce your need for more crowns in the future.
Thank you for sharing this information, i learned a lot in this post. All i know is dental fillings need not to be replace. thanks and good luck.
-heather-
Posted by: california cosmetic dentist | March 15, 2009 at 10:03 PM