Welcome to HCM! Thanks for posting your query. I am happy to address your questions. Vyvanse (lisdexamfetamine dimesylate) is a Schedule II controlled substance is indicated for the treatment of Attention Deficit Hyperactivity Disorder (ADHD). The dental decay as a result of using any stimulants is not due to bacteria caused by the suppression of the salivary glands to produce saliva but it is the other side of the stimulants that has a demineralizing effect on all traced minerals in our body. It causes to deplete Na+Magnesium, Calcium, Potassium, Chloride even glucose. When all the stored minerals are depleted in the liver the amphetamine salts will turn its sources from the other organs such as the bone, the hair, the nails & the teeth even from the muscles. In the teeth it demineralized them causing them to disintegrate from inside (dentin first) to the enamel outside. The best way to combat these demineralization is to take these traced minerals Na+, K+ , Mg+, via supplements. The secretion of saliva is just as well vital not only to our oral health but overall. Will need to be tapered slowly over a few weeks. Hope I have answered your query. If you have any further questions, I will be happy to help.