BEST GUM DENTIST IN ANNA NAGAR! Before the surgery a stent is created to protect the tissue donor site during the healing process. It’s a retainer-like piece of plastic to protect the roof of your mouth while you’re eating. This preoperative cast is usually a thermoplastic material that conforms to the roof of your mouth. Is it time for your checkup? Give us a ring at Apple Dental and let’s get you on the schedule.