ive never had a tongue piercing before, but just asked my friend who does pierce and he answered "dead cells, or it could be plaque build up. get soft bristle toothbrush and gently brush at it. glyoxide always helps too." i also had this aftercare guide written by him it was stored in my pc, maybe some of this info might help if you didnt know it already "PIERCING AFTERCARE Primary Oral Suggestions The optimal way to care for your oral piercing is to rinse your mouth for 30-60 seconds with a medical-grade oral rinse (such as tech 2000 or biotene) after every meal during the initial healing period (3-6 weeks). If a medical grade oral rinse is not available the next best thing is to dilute 4 ounces of an oral antiseptic with water. This will de-intensify the antiseptic and prevent it from irritating your piercing. Do not use mouth wash because it will do nothing for your piercing, only mask bad breath. Be careful not to over clean your piercing as this can prevent proper healing. Signs of over cleaning include a very white or yellow looking tongue. In addition to the oral rinse after every meal, sea salt rinse soaks will also help heal your piercing. First, fill a fresh disposable cup with 8 ounces of water and add ¼ teaspoon of sea salt, stirring until it is dissolved. Then, rinse your mouth for approximately 15 seconds. Sea salt rinses should be performed after smoking or drinking anything other than bottled water. Ice and other cold liquids can help reduce swelling. Ice pops, ice cream, and frozen yogurt, are also good ways to reduce swelling, but be sure to perform either a sea salt or oral rinse following your snack. This is not necessary if you use just use plain ice. Swelling tends to last 3-5 days. Brushing your teeth It is important to brush your teeth three times daily while your piercing is healing. Brushing your teeth will cut down on the amount of bacteria and food particles in your mouth. It is suggested that you purchase a new soft-bristle toothbrush to use during the initial healing period. Also, plaque (a white crusty shell) will begin to build up on your tongue jewelry if you do not gently brush the balls and post. You should brush your jewelry daily if you want to prevent plaque build up. " good luck!