Researchers predict that people may soon wear tooth fillings that incorporate an unusual type of glass. In a new study, researchers from Oregon State University (OSU) found that bioactive glass may reduce bacterial attack of composite tooth fillings and even replace losses from tooth decay.

The findings of the investigation show that compared to composite tooth fillings, the bacterial penetration in bioactive glass-made ones was notably smaller. With this, the researchers suggested that bioactive glass may indeed lengthen the life of fillings.

To come up with the results, the OSU engineers installed human molars into dentin disks that measure about 3 millimeters thick. They also placed 1.5 to 2 millimeter-deep composite restorations. Then, they purposely let a gap form between the dentin and composite by not putting an adhesive to that area.

The researchers then exposed both groups of samples to Streptococcus mutans biofilms. They placed the specimens in a bioreactor for two weeks and checked the cross-sectional area to see the gap profile.

The antimicrobial property of bioactive glass may be due to the release of ions such as phosphate and calcium, which are known to neutralize oral acidic environment and contain toxic effects on oral bacteria.

"Bioactive glass, which is a type of crushed glass that is able to interact with the body, has been used in some types of bone healing for decades," said study author Jamie Kruzic, who added that dentistry is just beginning to use this kind of glass and the new research already exhibited promising results. Kruzic also noted that the findings can have a significant impact on the future of dentistry.

The glass is called "bioactive" because the body is able to recognize its presence and respond to it, as opposed to other inert biomedical products.

Another good feature of bioactive glass is that it is hard enough to replace inert glass fillers that are incorporated with polymers to produce composite fillings.

The authors said being able to prolong the life of composite tooth fillings can be a vital step towards the advancement of dentistry. In the United States alone, more than 122 million restorations are being performed annually. People are said to chew about 600,000 times a year and the lifetime of a posterior dental composite is only approximately six years on the average.

The findings then present a vital significance to the delay of secondary tooth decay and restoration margins.

The study was published in the journal Dental Materials.