There are a few different types of glue that can be used for toothpick bridges, but the best type of glue to use is epoxy. Epoxy is a strong, durable adhesive that will hold your toothpicks in place and prevent them from falling out. It is also waterproof, so it will not come undone if it gets wet. To use epoxy, simply apply a small amount to the ends of your toothpicks and press them together. Hold them in place for a few minutes until the glue dries and then your bridge should be good to go!