A recent study has found validity in the continuation of grape seed extract study for oral health care. The study concluded that in their controlled studies grape seed extract slowed bacterial growth.
Tannin, or tannic acid, is a polyphenol that is present in wine. Tannic acid is found not only in grapes but also in chocolate, green tea, and several other unripe fruits and berries. Tannic acid is astringent attributing to the dryness of the wine. Other chemical components of tannins include being an anti-inflammatory, an anti-microbial, and an immune booster. Tannin inactivates adhesion and stops growth of polysaccharide cells which makes it a possible viable additive to oral health care products.
Keep in mind that while wine, in these preliminary studies, may help reduce bacterial growth that it does contain alcohol and high levels of acid. Alcohol, used out of moderation, can be detrimental to your health including liver damage. High levels of acid can contribute to gingival erosion and sensitivity of the teeth.
In the future we may see grape seed extract as a natural additive to our oral health care products due to its possible effects on dental decay reduction.