Glass teeth may sound like a really bad idea, but in a few years the seemingly fragile substance may be dentists preferred choice for filling cavities.
Medical researchers at Oregon State University have found that “bioactive” glass can reduce the combat oral bacteria, which results in longer life for fillings and better control over the progression of tooth decay.
Composite tooth fillings can be made of mixtures of resin or ceramics, and look more natural than the traditional dental fillings made of metal amalgam. But the traditional filings tend to be stronger, more durable and less expensive, so dental insurance plans may not cover or may limit the use of composites.
More than 122 million composite tooth restorations are performed in the United States every year. The average person chews 600,000 times annually. This force of chewing, combined with weakening from attacks by oral bacteria, gives a posterior dental composite life span of about six years. In some cases, composites will be covered by dental insurance for use in the front of the mouth, but metal will be stipulated for the back of the mouth.
People without dental insurance or dental savings plans can have a hard time finding the funds necessary to deal with their dental care needs. Having to replace filings every six or so years obviously creates an additional financial burden.
But bioactive glass is extremely tough. Made with compounds such as silicon oxide, calcium oxide and phosphorus oxide, it looks like powdered glass. It’s called “bioactive” because the body notices it is there and can react to it, as opposed to inert biomedical products. Bioactive glass can replace some of the inert glass fillers that are currently mixed with polymers to make composite tooth fillings.
Why would you want filings that your body reacts to? Because, after a filing, new tooth decay often begins at the interface of a filling and the tooth. This is called secondary tooth decay. The tooth is being eroded and demineralized at that interface by bacteria that is colonizing on and around the filing.
The antimicrobial effect of bioactive glass likely comes from the release of ions such as those from calcium and phosphate that have a toxic effect on oral bacteria and tend to neutralize acids in the mouth.
“Bioactive glass has been used in some types of bone healing for decades,” said Jamie Kruzic, a professor and expert in advanced structural and biomaterials in the OSU College of Engineering, in a statement.
“The bacteria in the mouth that helps to cause cavities don’t seem to like this type of glass and are less likely to colonize on fillings that incorporate it,” Kruzic added.
Even when bacteria does clamp onto the glass fillings, the depth of its penetration is significantly less than is commonly seen in composites without bioactive glass.
Fillings made with bioactive glass are also likely to provide minerals that can help strengthen a tooth weakened by decay.
If the laboratory findings are confirmed by clinical research, it should be very easy to incorporate bioactive glass into the formulas currently used for composite tooth fillings.