A team of engineers from Oregon State University propose the use of bioactive glass (BAG) to improve the longevity of dental fillings. In a study backed by the National Institute of Health and published in the journal of Dental Materials, the team showed through in vitro experimentation that molars with BAG fillings are resistant to secondary tooth decay, or damage to the filling that usually occurs over some six years after it has been implanted. Unlike most fillings that are inert in the mouth, these fillings are dynamic and react with the mouth’s chemistry to actively reduce tooth decay.
In their experiment, the researchers put fillings with 15% BAG into molar samples and compared them to molars that contained fillings without BAG as a control. They coated the molar discs with a bacterial biofilm and placed them in an environment that simulates that of the human mouth. After two weeks, they measured bacterial penetration into micro-crevices around the fillings. The depth of bacterial penetration in the molars with 15%-BAG fillings was 61% more shallow than penetration around the fillings that lacked BAG.
BAG has proven abilities to inhibit bacterial growth on a surface, and act as a buffer in acidic environments that can be harmful to a tooth’s enamel. Constructed out of silicon oxide, calcium oxide, phosphorus oxide, and other materials, the crushed glass releases phosphorus and silicon ions from its surface, neutralizing acidic ambient surroundings, similar to the way saliva buffers acid to reduce bacteria proliferation and tooth decay.
In addition, cyclic-loading tests showed that 15% BAG fillings have equal or superior mechanical robustness to the composites being used now.