100% Xylitol All-Natural Dental Defense System May Reduce the Risk of Tooth Decay Non-GMO Gluten-Free Sweetened Only With Xylitol Halal Kosher Spry Dental Defense System Spry—Improving Oral Health Frequent eating of foods high in sugars and starches can promote tooth decay. Clinical studies have shown that the use of xylitol on a daily basis, spread throughout the day, may reduce the risk of tooth decay. Every batch tested in USA to ensure the highest quality.