The researchers studied how treating gum disease in rats affects their risk of heart disease. They created gum disease in rats and tried different treatments. They found that levels of a harmful substance in the blood increased with gum disease but decreased with treatment. The rats that had their teeth removed and took antibiotics had the lowest levels. They also looked at certain proteins in the rats' arteries and found that gum disease made them more likely to have heart disease. Treating the gum disease helped lower this risk.