Comparison of Postoperative Sensitivity Following Bulk-Fill and Conventional Incremental Composite Restorations: A Randomized Controlled Trial at Tertiary Care Hospital of Peshawar

When a dentist fills a cavity, regular filling material shrinks as it hardens and cannot be penetrated deeply by the curing light, forcing dentists to painstakingly apply it in tiny 2 mm layers to prevent it from pulling away from the tooth walls and creating gaps for bacteria. To solve this, advanced "bulk-fill" composites were created; they are more see-through to let light reach the very bottom and contain flexible components that absorb their own shrinkage stress. This allows dentists to safely fill a deep 4 to 5 mm cavity all at once, saving significant time while still ensuring a tight, bacteria-proof seal.