Various factors influence the durability of resin fillings, including the filling's size and location, the patient's oral hygiene habits, and the materials used. On average, composite resin fillings can last between 5 to 10 years, but some may last even longer with proper care. It is important to maintain good oral hygiene, visit your dentist regularly for checkups and cleanings, and avoid habits that could damage your teeth, such as biting on hard objects or grinding your teeth.