Gauze is a very thin, sheer and loosely woven fabric that can be used for medical purposes, like covering wounds, or in crafting and sewing projects. Full definition
Use a dog / cat toothbrush or even an old rag or piece of gauze with a small dab of dog / cat toothpaste and gently rub along the outer surface of the teeth on both sides of the jaw and the front incisors. (peninsulahumanesociety.org)
When the teeth appear, it's time to switch to a baby's sized toothbrush instead of gauze pads or washcloths. (thebabycorner.com)