Present composite dental fillings used by dentists are not eternal, and as Professor Jamie Kruzic of the University of Oregon says, some of them may stop fulfilling their task after six years. That is why, with his team, he is working on a completely new material that is called bioactive glass.
Currently, composites used by dentists as fillings fill holes in our teeth are made of a mixture of polymers and inert glass fillers. They are composed of compounds such as phosphorus oxide, silicon oxide and calcium oxide, which repel bacteria that cause tooth decay. Specifically speaking, calcium and phosphate released ions are toxic to them.
The problem is that bacteria can put the colon in the gaps between the filling and the tooth, causing the tooth to break from the inside. That is why researchers have developed special, bioactive glass that, as demonstrated by laboratory tests, is much more resistant to such action.