Dental caries affects the majority of the worlds population and causes tooth decay and loss. Bacteria in the mouth cause this disease. Sugar consumption plays a role in causing these bacteria to make acid that results in dental caries. Studies have shown that a type of sugar alcohol, called xylitol, can help prevent this disease. We will be studying the growth of oral bacteria that cause dental caries. We will examine this growth after applying an oral ultrasound gel (manufactured by SmileSonica Inc) that contains xylitol.