These days, dental fillings are made from a variety of materials including gold, porcelain and composite resin. Each option has its own unique virtues and drawbacks, and all of them have finite lifespans. Metal amalgam fillings, which are typically the most durable options, have expected lifespans of about 15 years. Composite fillings, on the other hand, may only last about five years.
So why do fillings fail? The problem is due in large part to the fact that harmful bacteria colonies can continue form on surfaces between fillings and teeth. Over time, these bacteria can wear away teeth until fillings no longer effectively seal cavities. Now, however, a group of engineers at Oregon State University has proposed using a special type of glass in fillings that repels the oral bacteria that cause tooth decay.
It’s called bioactive glass, and it’s composed of the finely-ground dust of compounds such as phosphorous oxide, silicon oxide and calcium oxide. “The bacteria in the mouth that help cause cavities don’t seem to like this type of glass and are less likely to colonize on fillings that incorporate it. This could have a significant impact on the future of dentistry,” said Jamie Kruzic, professor of advanced structural and biomaterials in the OSU College of Engineering.
The dental applications of bioactive glass are just now being realized, but the material has actually been used in bone regeneration therapies for decades. Bioactive glass could not only slow secondary tooth decay, but also provide new minerals to teeth that have been demineralized due to decay.
The team at OSU hasn’t released concrete estimates as to the longevity of bioactive glass fillings, but they have reported success in their preliminary tests. “My collaborators and I have already shown in previous studies that composites containing up to 15 percent bioactive glass, by weight, can have mechanical properties comparable, or superior to commercial composites now being used,” said Kruzic in a statement.
It’s an exciting frontier of innovation that has the potential to make family dental fillings far more effective and long-lasting in the future.