A Narrative Review of the Material Properties, Clinical Efficacy, and Developmental Prospects of Bulk-Fill Resin-Based Composites

Bulk-fill resin-based composites (RBCs) have been developed as alternatives to conventional RBCs, offering advantages such as simplified clinical handling, reduced polymerisation shrinkage, improved restoration integrity, and increased resistance to microleakage that can compromise long-term clinical outcomes. These materials are applied in a single increment of 4-5 mm during restorative procedures, thereby minimising chair time and technique sensitivity without compromising restoration quality. Nonetheless, their clinical performance can be influenced by several factors, including material type and inherent properties (mechanical, optical, biocompatibility, polymerisation shrinkage, and conversion rate), curing parameters, the restorative technique used, storage conditions, the external oral environment, and preheating treatments. This article presents a comprehensive review of bulk-fill RBCs, discussing their concept, classifications, clinical applications, principal properties, and the critical factors that affect successful clinical outcomes. Additionally, it addresses the clinical limitations of bulk-fill RBCs and explores potential future developments. By synthesising the current evidence, this article aims to serve as a practical guide for clinicians and researchers, promoting informed decision-making and effective application of bulk-fill RBCs in restorative dentistry.