M. Victoria Moreno-Arribas and colleagues explain that dental diseases are extremely common throughout the world. Cavities, periodontal disease and tooth loss affect an estimated 60 to 90 percent of the global population. The problems start when certain bacteria in the mouth get together and form biofilms, which are communities of bacteria that are difficult to kill. They form plaque and produce acid, which starts damaging teeth. Brushing, fluoride in toothpaste and water and other methods can help get rid of bacterial plaques, but the effects are limited. In addition, currently used antimicrobial rinses can change the color of the gums and alter taste, so people are less likely to use them for as long as they should. Some research has suggested that polyphenols, grape seed extract and wine can slow bacterial growth, so Moreno-Arribas' team decided to test them under realistic conditions for the first time.
They grew cultures of bacteria responsible for dental diseases as a biofilm. They dipped the biofilms for a couple of minutes in different liquids, including red wine, red wine without the alcohol, red wine spiked with grape seed extract, and water and 12 percent ethanol for comparison. Red wine with or without alcohol and wine with grape seed extract were the most effective at getting rid of the bacteria.